Manual - 8500A Series Peak Power Meter - Giga-tronics

Manual Part Number: 20790 

Revision Level: D-1 

Configuration Code: 27 

Print Date: March 2009 

Operation & Maintenance Manual 

Series 8500A 

Peak Power Meters 

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Certified Product 

ISO 9001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Certified Process 

Registra: BSI, Certification No. FM 34226, Registered 04 June 1996 

Giga-tronics Incorporated ❖ 4650 Norris Canyon Road ❖ San Ramon, California 94583 

Telephone (925) 328-4650 or (800) 726-4442 ❖ Telefax (925) 328-4700 

Customer Service: Telephone (800) 444-2878 ❖ Telefax (925) 328-4702 

Web Site: www.gigatronics.com 

Superceded by Revision D, March 2009

All technical data and specifications is this manual are subject to change without prior notice and 

do not represent a commitment on the part of Giga-tronics Incorporated. 

©Copyright Giga-tronics Incorporated 2009. All rights reserved. 

Printed in U.S.A. 

WARRANTY 

Giga-tronics Series 8500A instruments are warranted against defective 

materials and workmanship for one year from date of shipment. 

Giga-tronics will at its option repair or replace products that are proven 

defective during the warranty period. This warranty DOES NOT cover 

damage resulting from improper use, nor workmanship other than 

Giga-tronics service. There is no implied warranty of fitness for a 

particular purpose, nor is Giga-tronics liable for any consequential 

damages. Specification and price change privileges are reserved by 

Giga-tronics. 

Model Numbers 

The Series 8500A includes two models: The single-channel Model 8501A and the dual-channel 

Model 8502A. Apart from the number of sensors they support, the two models are identical. Both 

models are referred to in this manual by the general term 8500A, except where it is necessary to 

make a distinction between the models. 


Errata Sheet 

for 

Series 8500A Peak Power Meter 

Operation & Maintenance Manual 

Manual P/N 20790 

Issued March 10, 2009 

Correction: Change in Performance Specifications 

Description of Correction: This change applies to the Giga-tronics 8500A series Peak Power Meter with 

the model 17071A 40 GHz Power Sensor. The change is to the measurement Power Range only: 

Old 17071A specification: 

750 MHz to 40 GHz 

Peak Power Range: -20 to +20 dBm and CW Power Range: -40 to +20 dBm 

New 17071A specification: 



>18 GHz to 40 GHz 


All other specifications remain the same. 

© 2009 Giga-tronics Incorporated. 


QUICK REFERENCE CARD 

Giga-tronics Model 8501A and 8502A Functional Commands 

This card is a summary of commands required to manually activate the functions of the Series 8500A Peak Power Meters (PPM). The commands are listed for each of the different modes of operation of the PPM 

(All Modes, CW, Peak, Graph, Dual Channel, and 1018B Emulation). Keys that are to be pressed for the command sequence are enclosed in brackets. For simplicity, values are given as a single command rather 

than as individual numbers (for example, 0.1 is shown as [0.1] rather than [0][.][1]). The [UNITS] command at the end or included with some of the command keystroke sequences means to press any of the three 

units keys (ms, µs, or ns) to enter the values of the keyed sequence. Numbers in parenthesis after a MENU or MEM key means to press the key that number of times to reach a specific menu level. 

Commands Applicable to All Modes 

Auto Zero Detectors 

[MENU] (1) [F3] [F2] 

Calibrate Detectors 

[MENU] (1) [F3] [F1] 

Self-Test the PPM 

[MENU] (11) [F2] 

(during a test routine) 

Service Functions 

[MENU] (1) [F1] 

Detector Offset (Channel A) 

[MENU] (3) [F1] [nn.nn] [dB] 

Detector Offset (Channel B) 

Frequency Correction 

[FREQ] (follow prompts) 

Frequency Correction - 

[MENU] (3) [F3] [F1] [nnn.nnn] [GHz] 

User Freq/PROM 


V/GHz/PROM 

[MENU] (3) [F3] [F2] [vv.vv] [UNITS] [xx.xx] 

[ff.ff] [GHz] 


[MENU] (3) [F3] [F3] [A] or [B] [nn.nn] [dB] 

Cal Factor (dB) 

Change Units Between dBm and mW [MENU] (4) [F3] (toggle) 

Hide/Display Frequency Information [MENU] (7) [F3] (toggle) 

Review Detector PROM Information [MENU] (10) [F2] (ch A) or [F3] (ch B) 

Check Date and Time then Exit 

[MENU] (5) [F3] [F3] 

Change Date and Time then Exit [MENU] (5) [F3] [F1] [mmddyy] [UNITS] 

[hhmmss] [UNITS] [F3] 

Set Max and Min Power Limits 

[MENU] (7) [F1] [nn.nn] [UNITS] [nn.nn] [dBm] 

Recall Setup (n) in Memory 

[MEM] (1) [F1] [n] [UNITS] 

Store Setup (n) in Memory 

[MEM] (1) [F2] [n] [UNITS] 

Recall Power-On Setup 

[MEM] (1) [F3] 

Display Current Setup 

[MEM] (2) [F1] [F1] or [F3] (F1 = more 

Display Power-On Setup 

[MEM] (2) [F2] [F1] or [F3] (F1 = more 

Display Setup (nn) in Memory 

[MEM] (2) [F3] [nn] [UNITS] [F1] (more) or [F3] 

(exit) 

Initialize Current Setup 

[MEM] (3) [F1] 

Initialize All But Current Setup 

[MEM] (3) [F2] 

Initialize a Numbered Setup (nn) [MEM] (3) [F3] [nn] [UNITS] 

CW Mode Commands 

Select CW Mode 

[CW] 

CW Averaging 

[MENU] (2) [F1] [nnn] [UNITS] 

Fast Analog Output 

[MENU] (10) [F1] 

Graph Mode Commands 

Select GRAPH Mode 

[GRAPH] 

Select 8501A Internal Trigger and Level [MENU] (1) [F1] [nn.nn] [dBm/mW] 

Select 8502A Internal Trigger and Level [MENU] (1) [F1] [A] or [B] [nn.nn] [dBm/mW] 

Select External Trigger 

[MENU] (1) [F2] 

Peak Averaging 

[MENU] (2) [F2] nnn [UNITS] 

Set Initial Delay for Autoscaling 

[MENU] (9) [F2] [nn.nn] [UNITS] 

Set Average Value for Autoscaling [MENU] (9) [F3] [nn.nn] [UNITS] 

Enter Reference Delay [MENU] (4) [F1] (for ch A) or [F2] (for ch B) 

[nn.nn] [UNITS] 

Clear Reference Delay 

[MENU] (4) [F1] (ch A) or [F2] (ch B) [0] [UNITS] 

Graph Mode Commands (continued) 

Marker Sub-Mode Commands 

Change Marker 1 Percentage 

Move cursor to MRKR 2-1 line on display, press 

[*nn.n] [UNITS] 








Move cursor to 4th line on display, press [*nn.n] 

[UNITS] 

* Enter [nn.n] (positive) to place the marker on the rising edge of the pulse. 

Enter [-nn.n] (negative) to place the marker on the falling edge of the pulse. 

GPIB Plotting 

GPIB Plot (Paper) 

GPIB Plot (Transparency) 

Code Number Entry for Plot 

Part Number Entry for Plot 

Abort (Stop) Plotting Activity 

Enter Plotter GPIB Address 

Peak Mode Commands 

[MENU] (2) [F3] [F1] 

[MENU] (2) [F3] [F2] 

[MENU] (5) [F1] [nnnn] [UNITS] 

(nnnn = up to 12 digits) 

[MENU] (5) [F2] [nnnn] [UNITS] 

(nnnn = up to 12 digits) 

[MENU] (6) [F1] 

[MENU] (6) [F2] [nn] [UNITS] 

Select Peak Mode 

[PEAK] 

Select 8501A Internal Trigger and Level [MENU] (1) [F1] [nn.nn] [dBm] [mW] 

Select 8502A Internal Trigger and Level [MENU] (1) [F1] [A] or [B] [nn.nn] [dBm] [mW] 


[MENU] (1) [F2] 


[MENU] (10) [F1] 


[MENU] (2) [F2] nn [UNITS] 

Enable Cursor Delay 

[↑] or [↓] 

Disable Cursor Delay 

[UNITS] 

Enter Reference Delay 

[MENU] (4) [F1] (ch A) or [F2] (ch B) [nn.nn] 

[UNITS] 

Clear Reference Delay [MENU] (4) [F1] (ch a) and/or [F2] (ch b) [0] 

[UNITS] 

Other Dual Channel Commands 


Display Ratio A/B Power Mode 

Select Peak Mode for Channel A 

Select CW Mode for Channel A 

Select Peak Mode for Channel B 

Select CW Mode for Channel B 

Exit Ratio Mode 

[MENU] (3) [F2] [nn.nn] [dB] 

[MENU] (7) [F2] 

[A] [F1] (when using the Ratio Mode) 


[B] [F1] (when using the Ratio Mode) 


[CW] or [PEAK] 

Change Between Cursor, Marker, 

and Pulse Sub-Modes 

Cursor Sub-Mode Commands 

Change Start Delay 

Change Window Delay 

Change Cursor Delay 

Change Internal Trigger Level 

Change Reference Power 

(100% Point) 

Pulse Sub-Mode Commands 

Change Pulse Width Start/End % 

Change Rise Time Start/End % 

Change Fall Time Start/End % 

PULSE/CURSOR/MARKER (triple toggle) 

Move cursor to STRT DLY line on display; enter 

change using [nn.nn] [UNITS] or spin knob 

Move cursor to DLY WIND line on display; enter 


Move cursor to CSR DLY line on display; enter 


Move cursor to TRG LEV line on display; enter 

change using [nn.nn] [UNITS] (or spin knob); or 

use [MENU] (1) [F1] [nn.nn] [UNITS] 

Move cursor to REF PWR line on display; enter 

change using [nn.nn] [UNITS] 

Move cursor to PULSE WID line on display, press 

[nn.n] [UNITS] [nn.n] [UNITS] 

Move cursor to RISE TIME line on display, press 


Move cursor to FALL TIME line on display, press 


IEEE & 1018B Emulation Commands 

Select PPM Listen and Talk Address [MENU] (6) [F3] [nn] [UNITS] 

Initiate 1018B Emulation Mode 

[MENU] (8) [F2] 

* Disable/Enable Service Request [MENU] (8) [F1] (toggle) 

* Automatic/Bus Command Trigger [MENU] (8) [F2] 

Reset 

* Get Data Fast (No Display) [MENU] (8) [F3] 

* Set Measurement Range [MENU] (9) [F1] (for nnn.n µW) 

[MENU] (9) [F2] (for nn.nn mW) 

[MENU] (9) [F3] (for n.nnn mW) 

* Set Initial Delay for Autoscaling [MENU] (11) [F2] [nn.nn] [UNITS] 

* Set Averaging Value for Autoscaling [MENU] (11) [F3] [nnn] [UNITS] 

* End 1018B Emulation Mode [MENU] (10) [F2] 

* These commands are valid only in 1018B Emulation Mode. 

(See other side for a Quick Reference to Menu Displays)

QUICK REFERENCE CARD 

Giga-tronics Model 8501A and 8502A Menu Displays 

This card is a quick reference to the menus that will display when the MENU and MEMory keys are pressed. The number in parenthesis after the key is the number of times the key must be pressed to reach the 

designated menu. MENU (1) means to press the MENU key one time; MEM (2) means to press the MEMory key two times, etc. Two levels of menu displays are available. The first level includes menus for normal 

8500A functions. The second level are the menus used during 1018B emulation. MENU (8) in the normal mode enables or toggles the 1018B Emulation mode. 

MENU Key Displays 

Normal 8500A Functions 

MENU Key Displays (continued): 

1018B Emulation Mode Functions 

Keystrokes 

Menu Displayed 

Keystrokes 


MENU (1) 

MENU (2) 

MENU (3) 

Menu = NEXT MENU 

F1 set Int Trig and Level 

F2 set Extrn Trigger 

F3 to Cal or Zero Detectors 

Menu = NEXT MENU; Minus = PREV MENU 

F1 to Enter CW Averaging Number 

F2 to Enter Peak Averaging Number 

F3 for GPIB Plot 


MENU (8) 

MENU (8) 

(Bus Trigger Reset; SRQ Enabled) 

Press CLEAR to return to data display 

F1 to Disable SRQ (Service Request) 

F2 for Automatic Trigger Reset 

F3 to Get Data Fast; No EL Data Display 

(Auto Trigger Reset; SRQ Disabled) 


F1 to Enable Service Request 

F2 for Bus Command Trigger Reset 


MENU (4) 

F1 to Enter Detector A Offset 

F2 to Enter Detector B Offset (8502A only) 

F3 to Enter Source of Frequency Correction 


F1 to Enter Detector A Ref Delay 

F2 to Enter Detector B Ref Delay (8502A only) 

F3 to Select mW Format 

MENU (9) 

MENU (10) 


Current Range Value is X 

F1 for Range 1 (XXX.X µW) 

F2 for Range 2 (XX.XX mW) 

F3 for Range 3 (X.XXX mW) 


Press MENU for next lower level menu 

MENU (5) 


F2 to end 1018B Emulation 

MENU (6) 

F1 to Enter Code Number 

F2 to Enter Part Number 

F3 for Read and Set Time 

Menu = NEXTR MENU; Minus = PREV MENU 

MENU (11) 

MENU (12) 

MENU (13) 

(Same as MENU (8) for the normal 8500 mode.) 



MENU (7) 

F1 to Abort Current Plotting Activity 

F2 to Enter Plotter Address 

F3 to Enter 8500A Listen and Talk Address 


MEMory Key Displays 

Keystrokes 


MENU (8) 

F1 to Set Max and Min Power Limits 

F2 to Select Ratio Display Mode (8502A only) 

F3: Hide (or Display) Frequency Information 


MEM (1) 

Press MEM for additional selections 

F1 to Recall Setups 

F2 to Store Setups 

F3 to get Power-On Setup 

F2: Emulate 1018B 

MEM (2): 


MENU (9) 


F1 to Program Detector PROM 

F2 to Set Initial Dly Value for Autoscaling 

F3 to Set Averaging Value for Autoscaling 

MEM (3): 

F1 to Display Current Setup 

F2 to Display Power-On Setup 

F3 to Display a Numbered Setup 


MENU (10) 

NOTE: F1 is used only with the PROM Programmer 


F1 to Re-Initialize the Current Setup 

F2 to Re-Initialize All but Current Setup 

F3 to Re-Initialize a Numbered Setup 

F1 for Fast Analog Output 

F2: Review A Detector PROM 

F3: Review B Detector PROM (8502A only) 

MENU (11) 

Minus = PREV MENU 

Be Sure No RF is Applied to Detector 

Press CLEAR to Skip All Tests 

F1 for Service Functions 

F2 for Self Test 

(See other side for a Quick Reference to Functional Commands)

Table of Contents 

About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Record of Manual Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Special Configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

ix 

xi 

xiii 

xv 

1 • Introduction _______________________________________________________ 

1.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 

1.1.1 Environmental Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 

1.1.2 Items Furnished . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 

1.1.3 Items Required. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 

1.1.4 Tools and Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 

1.1.5 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 

1.1.6 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 

1.1.7 Receiving Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 

1.1.8 Returning an Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 

1.2 System Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 

1.3 Default Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 

2 • Operation _________________________________________________________ 

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 

2.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 

2.2.1 PCB-Oriented Voltage Selector and Fuse Holder . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 

2.2.2 VDE Type Voltage and Fuse Holder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 

2.3 Rear Panel Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 

2.4 Front Panel Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 

2.5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 

2.5.1 Power On Self-Test (POST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 

2.5.2 Warm Up Time and Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 

2.6 Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 

2.6.1 CW Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 

2.6.2 Peak Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 

2.6.3 Graph Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13 

2.7 Self-Calibration and Auto-Zeroing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14 

2.7.1 Self-Calibration Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14 

2.7.2 Self-Calibration Failures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 

2.7.3 Auto-Zero Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 

2.8 Measurement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16 

2.8.1 Frequency Correction, Cal Factor, and dB Offset . . . . . . . . . . . . . . . . . . . . . . . . . 2-16 

2.8.2 PROM Frequency Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16 

2.8.3 User-Supplied Cal Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 

2.8.4 CW Power Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18 

2.8.5 Peak Power Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 

2.8.6 Peak Power Measurements Using the Graph Mode . . . . . . . . . . . . . . . . . . . . . . . 2-23 

2.8.7 Pulse, Cursor, and Marker Readouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23 

2.8.8 Cursor Sub-Mode Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24 

2.8.9 Pulse Parameters Sub-Mode Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26 

Manual No. 20790, Rev C, November 1998 

i 


Series 8500A Peak Power Meters 

2.8.10 Marker Sub-Mode Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 

2.9 Digital Plotting of Graphic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 

2.9.1 Plotters Supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 

2.9.2 Procedure for Making Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 

2.10 Dual Channel Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32 

2.10.1 CW, CW Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32 

2.10.2 Peak, Peak Measurements: Method 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32 

2.10.3 Peak, Peak Measurements: Method 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 

2.10.4 Peak, CW Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34 

2.10.5 Power Ratio Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35 

2.11 High Power Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37 

2.11.1 Power Warning - Max/Min Power Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37 

2.12 High Power Measurement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37 

2.12.1 High Power Relative Measurements (8502A only) . . . . . . . . . . . . . . . . . . . . . . . . . 2-39 

2.13 Special Capabilities of the PPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40 

2.13.1 Reference Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40 

2.13.2 Single Pulse Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40 

2.13.3 Single Pulse Measurement Using Internal Trigger . . . . . . . . . . . . . . . . . . . . . . . . . 2-40 

2.13.4 Single Pulse Measurement With an External Trigger . . . . . . . . . . . . . . . . . . . . . . . 2-41 

2.14 Swept Peak Power Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42 

2.15 Self-Testing the 8500A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-44 

2.16 Frequency Display Disable/Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45 

2.17 Non-Volatile Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45 

2.17.1 Memory Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45 

2.18 1018B Peak Power Meter Emulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47 

2.18.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47 

2.18.2 Initiating the 1018B Emulation Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47 

3 • Remote Operation __________________________________________________ 

3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 

3.2 Remote Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 

3.2.1 PPM IEEE Bus Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 

3.2.2 Front Panel Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 

3.2.3 Power-On Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 

3.2.4 Remote and Local Lockout Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 

3.2.5 Output Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 

3.2.6 Command String Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12 

3.2.7 Power Measurement Data Output Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12 

3.3 GPIB Command Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14 

3.3.1 Common Mode Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15 

3.3.2 Measurement Data Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17 

3.3.3 Mode Selection and Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21 

3.3.4 Commands for Retrieving Data From the PPM . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23 

3.3.5 Graph Mode GPIB Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24 

3.3.6 Marker Timing Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26 

3.3.7 Manual Marker Placement/Timing Measurement Commands . . . . . . . . . . . . . . . . 3-29 

3.3.8 Window and Cursor Control Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31 

3.3.9 Commands to Output Graphic Data to a Controller . . . . . . . . . . . . . . . . . . . . . . . . 3-33 

3.3.10 Plotting Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34 

3.3.11 Programming Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35 

3.4 Service Requests and Serial Poll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36 

3.4.1 Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37 

3.5 1018B Emulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38 

ii Manual No. 20790, Rev C, November 1998 


Preface 

3.6 Status Code Decimal Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41 

3.7 Summary of Bus Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43 

3.7.1 Normal PPM Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43 

3.7.2 PPM Stand Alone Plot Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43 

3.8 GPIB Command Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44 

3.9 1018B Emulation Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52 

3.10 Data Formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52 

4 • Theory of Operation ________________________________________________ 

4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 

4.2 System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 

4.2.1 Power Supply PC Assembly (A2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 

4.2.2 GPIB/CAL Control PC board (A3). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 

4.2.3 CPU PC Assembly (A4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8 

4.2.4 Digital Delay PC Assembly (A5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12 

4.2.5 Analog PC Assembly (A6/A7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20 

4.2.6 Front Panel Interface PC Assembly (A8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24 

4.2.7 Calibrator PC Assembly (A12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27 

5 • Testing and Calibration _____________________________________________ 

5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 

5.2 Performance Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 

5.2.1 Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 

5.2.2 Calibrator Return Loss Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 

5.2.3 Calibrator Output Level Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 

5.2.4 Instrument Plus Power Detector Linearity Test . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 

5.2.5 Power Linearity Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 

5.2.6 Delay Accuracy Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6 

5.2.7 Analog Output Accuracy Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 

5.2.8 Voltage Proportional to Frequency Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 

5.2.9 Detector Return Loss Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 

5.2.10 Plotter Output/IEEE-488 Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 

5.3 Calibration Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 

5.3.1 Calibration Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 

5.3.2 Preset Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 

5.3.3 A2 Regulator Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 

5.3.4 Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 

5.3.5 A8 Front Panel Interface Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 

5.3.6 A6/A7 Analog Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13 

5.3.7 A3 GPIB/CAL Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15 

5.3.8 A4 CPU Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15 

5.3.9 A5 Digital Delay Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16 

5.3.10 External Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 

5.3.11 Volume Adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 


iii 



6 • Maintenance _______________________________________________________ 

6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 

6.2 Periodic Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 

6.2.1 Required Test Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 

6.3 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 

6.3.1 Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 

6.3.2 Power-On Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 

7 • Parts Lists ________________________________________________________ 

7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 

7.2 Parts Lists for Series 8500A Peak Power Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 

8501A PEAK POWER METER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 

8502A DUAL INPUT PEAK POWER METER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 

20512-A00 8501A CHASSIS ASSY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3 

20513-A00 8502A CHASSIS ASSY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4 

21145 FRONT SUB PANEL ASSY 8501A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 

21147 FRONT SUB PANEL ASSY 8502A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 

21146 REAR PANEL ASSY 8501A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 

21148 REAR PANEL ASSY 8502A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 

20879 EL DISPLAY MODULE ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 

20879-A00 EL DISPLAY MODULE SUB ASSY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 

16869 DELAY LINE ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 

16932-001 INTERCONNECT PCB ASSY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 

16932-A01 PCB ASSY PRE-WAVE,INTERCONNECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 

16995 PCB ASSY, POWER SUPPLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10 

16995-A00 PCB ASSY PRE-WAVE, PWR SUPPLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10 

21014 PCB ASSY GPIB/CAL CONTROL 8500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13 

21014-A00 PCB ASSY PRE-WAVE,GPIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13 

16878 PCB ASSY., CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16 

16878-A00 PCB ASSY PRE-WAVE, CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16 

16685 P.C. ASSY, DIGITAL DELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19 

16685-A00 PCB ASSY PRE-WAVE, DIG. DELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20 

20741 ANALOG PCB ASSY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24 

20741-A00 PCB ASSY PRE-WAVE, ANALOG. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24 

20195 PCB ASSY, FR PNL INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-30 

20195-A00 PCB ASSY PRE-WAVE,FRT PNL INT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-30 

20526-001 PC BOARD ASSY, FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-33 

20055-001 ASSY, 1GHZ CALIBRATOR TYPE N. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34 

20055-A01 CALIBRATOR SUB ASSY, TYPE N. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34 

7.3 List of Manufacturers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-36 

8 • Diagrams__________________________________________________________ 

8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 

8.2 Applicability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 

Model 8501A/8502A Peak Power Meter, DWG# 20522. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3 

Interconnect PC Assy (A1), DWG# 16932-001. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5 

Interconnect Circuit Schematic (A1), DWG# 21088 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6 

Power Supply PC Assy (A2), DWG# 16995 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9 

Power Supply Circuit Schematic (A2), DWG# 16996. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10 

GPIB/Cal Control PC Assy (A3), DWG# 21014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12 

GPIB/Cal Control Circuit Schematic (A3), DWG# 21015 . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13 

CPU PC Assy (A4), DWG# 16878 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15 

iv Manual No. 20790, Rev C, November 1998 


Preface 

CPU Circuit Schematic (A4), DWG# 16879 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16 

Digital Delay PC Assy (A5), DWG# 16685 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18 

Digital Delay Circuit Schematic (A5), DWG# 16686 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19 

Analog PC Assy (A6/A7), DWG# 20741 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-22 

Analog Circuit Schematic (A6/A7), DWG# 20742 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-23 

Front Panel Interface PC Assy (A8), DWG# 20195. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26 

Front Panel Interface Circuit Schematic (A8), DWG# 20196 . . . . . . . . . . . . . . . . . . . . . . . 8-27 

Front Panel Interface PC Assy (A9), DWG# 20526-001 . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-30 

Front Panel Interface Circuit Schematic (A9), DWG# 20527 . . . . . . . . . . . . . . . . . . . . . . . 8-31 

1 GHz Calibrator Assy, DWG# 20055-001. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-32 

1GHz Calibrator Schematic (A12), DWG# 17097 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-33 

A • Summary of Commands ____________________________________________ 

A.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1 

A.2 Commands Applicable to All Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1 

A.3 CW Mode Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3 

A.4 Peak Mode Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3 

A.5 Graph Mode Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4 

A.5.1 Change Between Cursor, Marker, and Pulse Sub-Modes . . . . . . . . . . . . . . . . . . . A-5 

A.5.2 Cursor Sub-Mode Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5 

A.5.3 Pulse Sub-Mode Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5 

A.5.4 Marker Sub-Mode Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5 

A.6 Dual Channel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6 

A.6.1 CW Mode Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6 

A.6.2 Peak Mode Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6 

A.6.3 Other Dual Channel Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6 

A.6.4 IEEE & 1018B Emulation Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6 

B • Menu and Memory Keys ____________________________________________ 

B.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1 

B.2 MENU Key Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1 

B.2.1 Normal 8500A Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1 

B.2.2 1018B Emulation Mode Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3 

B.3 MEMory Key Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4 

C • Display Formats ___________________________________________________ 

C.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1 

C.2 Data Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1 

D • RF Detectors______________________________________________________ 

D.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1 

D.2 Detector Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2 

D.3 Electrical Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4 

D.3.1 Preamplifier PC Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4 

D.3.2 PROM PC Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-6 

D.4 Detector Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-7 

D.5 Detector Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-7 

D.5.1 Disassembly of Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-8 

D.5.2 Replacement of Detector Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-8 

D.5.3 Reassembly of Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-9 


v 



E • Options ___________________________________________________________ 

E.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1 

E.2 Option 01: Rack Mount Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1 

E.3 Option 03: Rear Panel Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2 

1 • Index _____________________________________________________________ 

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index-1 

vi Manual No. 20790, Rev C, November 1998 


Preface 

List of Figures 

Figure 2-1 Power Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 

Figure 2-2 PCB Voltage Selector and Fuse Holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 

Figure 2-3 VDE Voltage Selector and Fuse Holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 

Figure 2-4 Model 8502A Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 

Figure 2-5 Model 8502A Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 

Figure 2-6 Typical Single Channel Peak Power Display . . . . . . . . . . . . . . . . . . . . . . . . 2-21 

Figure 2-7 Typical Initial Graph Mode Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23 

Figure 2-8 Typical Cursor Sub-Mode Digital Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24 

Figure 2-9 Typical Pulse Sub-Mode Digital Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26 

Figure 2-10 Typical Marker Sub-Mode Digital Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 

Figure 2-11 Typical Signal Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 

Figure 2-12 Typical Peak Power Ratio Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35 

Figure 2-13 Typical Good & Bad Cursor Delay Settings . . . . . . . . . . . . . . . . . . . . . . . . . 2-36 

Figure 2-14 Detector to a High-Power Coupler Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38 

Figure 2-15 Detector to High Power Attenuator Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38 

Figure 2-16 Typical Pulse with -10 dBm Trigger Level . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40 

Figure 2-17 Typical Pulsed Swept Measurement System . . . . . . . . . . . . . . . . . . . . . . . . 2-42 

Figure 4-1 Series 8500A System Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 

Figure 4-2 GPIB/Cal Control (A3) Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 

Figure 4-3 Voltage to Current Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6 

Figure 4-4 CPU (A4) Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8 

Figure 4-5 Digital Delay (A5) Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12 

Figure 4-6 Timing Diagram - Delay Board Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14 

Figure 4-7 Analog PC (A6/A7) Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20 

Figure 4-8 Front Panel Interface (A8) Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24 

Figure 4-9 Detector Calibrator (A12) Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27 

Figure 5-1 Power Linearity Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 

Figure 5-2 Delay Accuracy Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6 

Figure 5-3 Model 8501A/8502A Calibration Components. . . . . . . . . . . . . . . . . . . . . . . . 5-9 

Figure 5-4 Typical PPM Digital Delay Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16 

Figure 5-5 Typical PPM Display with A5R30 at Max cw . . . . . . . . . . . . . . . . . . . . . . . . 5-17 

Figure 5-6 Typical PPM Display w/Smooth Rise Time . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17 

Figure 5-7 Typical PPM Sync Output Scope Display . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 

Figure D-1 Op-Amp Equivalent of Pre-Amp Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4 

Figure D-2 Pre-Amplifier/Line Driver Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5 

Figure D-3 PROM PC Assembly Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-6 

Figure D-4 Detector Disassembly and Assembly Details . . . . . . . . . . . . . . . . . . . . . . . . D-10 


vii 



List of Tables _________________________________________________________ 

Table 2-1 Self-Test Error Flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-44 

Table 3-1 Status Code Values and Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41 

Table 3-2 Summary of Bus Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43 

Table 3-3 GPIB Commands Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44 

Table 3-4 1018B Emulation Commands Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52 

Table 4-1 A2 Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 




Table 4-5 A6/A7 Analog Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23 

Table 4-6 A8 Interface Assembly Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26 

Table 5-1 Required Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 

Table 5-2 Required Calibration Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 

Table 5-3 Multiples of 25.6 ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18 

Table 6-1 Required Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 

Table 8-1 Series 8500A Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 

viii Manual No. 20790, Rev C, November 1998 


About This Manual 

This manual contains the following chapters and appendices to describe the operation and 

maintenance of Series 8500A Peak Power Meters: 

Preface: In addition to a comprehensive Table of Contents and general information about the 

manual, the Preface also contains a record of changes made to the manual since its publication, and 

a description of Special Configurations. If you have ordered a user-specific manual, please refer to 

page xv for a description of the special configuration. 

Chapter 1: Introduction: This is an introduction to the instrument and performance parameters. 

Chapter 2: Operation: This is a guide to the instrument front panel keys, display and 

configuration menus. 

Chapter 3: Remote Operation: This is a guide to the GPIB remote control interface. 

Chapter 4: Theory of Operation: This chapter a block diagram level description of the instrument 

and its circuits for maintenance and applications. 

Chapter 5: Calibration and Testing: procedures for inspection, calibration, and performance 

testing are outlined in this chapter. 

Chapter 6: Maintenance: This chapter contains procedures for maintenance and troubleshooting. 

Chapter 7: Parts Lists: This chapter lists all components and parts and their sources. 

Chapter 8: Diagrams: This chapter contains schematics and parts placement diagrams for all 

circuits. 

Appendix A: Summary of Commands: A summary of the commands used to operate the Series 

8500A front the front panel. 

Appendix B: Menu and Memory Keys: A summary of the menus and functions that can be 

accessed with the MENU and MEMory keys. 

Appendix C: Data Display Formats: A summary of the data display formats with the 

corresponding mode and detector selection switches. 

Appendix D: RF Detectors: Selection data for power detectors, specifications, and calibration 

procedures. 

Appendix E: Options: This appendix will be included only when necessary to describe options 

that are available for the Series 8500A power meters. 

Changes that occur after publication of the manual, and special configuration data will be inserted 

as loose pages in the manual binder. Please insert and/or replace the indicated pages as detailed in 

the Technical Publication Change Instructions included with new and replacement pages. 


ix 



x Manual No. 20790, Rev C, November 1998 


Conventions 

The following conventions are used in this product manual. Additional conventions not included 

here will be defined at the time of usage. 

Warning 

WARNING 

The WARNING statement is enclosed in double lines and centered in 

the page. This calls attention to a situation, or an operating or 

maintenance procedure, or practice, which if not strictly corrected or 

observed, could result in injury or death of personnel. An example is 

the proximity of high voltage. 

Caution 

CAUTION 

The CAUTION statement is enclosed within a single heavy line and 

centered in the page. This calls attention to a situation, or an operating 

or maintenance procedure, or practice, which if not strictly corrected 

or observed, could result in temporary or permanent damage to the 

equipment, or loss of effectiveness. 

Notes 

☛ NOTE: A NOTE highlights or amplifies an essential operating or 

maintenance procedure, practice, condition or statement. 

Keys 

Front panel keys intended to be pressed are contained within brackets, such as [MENU], which 

means to press the MENU key. The Menu and Memory keys may be followed by a number in 

parenthesis. This means to press the key that number of times to reach a specific level. 


xi 



Symbols 

Block diagram symbols frequently used in the manual are illustrated below. 

Course 

MOD 

Fine 

YIG 

STEP 

ATTEN 

LVL 

Pulse 

Modulator 

YIG-Tuned 

Oscillator 

Mixer 

Switch 

Step 

Attenuator 

PIN-Diode 

Leveler 

DAC 

LOW 

PASS 

Digital to 

Analog 

Converter 

RF Level 

Detector 

Coupler 

Fixed 

Reference 

Oscillator 

Filter 

Voltage- 

Controlled 

Oscillator 

Step-Recovery 

Diode Multiplier 

Digital 

Data 

V 

R 

Phase Lock 

Loop 

DIV 

N 

Frequency 

Divider 

Isolator 

Amplifier 

xii Manual No. 20790, Rev C, November 1998 


Record of Manual Changes 

This table is provided for your convenience to maintain a permanent record of manual change data. 

Corrected replacement pages will be issued as Technical Publication Change Instructions, and will 

be inserted at the front of the binder. Remove the corresponding old pages, insert the new pages, 

and record the changes here. 

Change Instruction 

Number 

Change Instruction 

Date 

Date 

Entered 

Comments 


xiii 



xiv Manual No. 20790, Rev C, November 1998 


Special Configurations 

When the accompanying product has been configured for user-specific application(s), supplemental 

pages will be inserted at the front of the manual binder. Remove this page and replace it with the 

furnished Special Configuration supplemental page(s). 


xv 



xvi Manual No. 20790, Rev C, November 1998 


1 

Introduction 

1.1 Description 

The Giga-tronics 8500A Series Peak Power Meters (PPM) are designed for the analysis and power 

measurement of pulsed RF and microwave signals produced by microwave component devices. 

The PPM converts RF energy to dc voltage by using balanced (dual Schottky diode), zero-biased, 

detectors with very fast rise times. The dc voltage is measured with an autoranging dc amplifier, and an 

A/D converter provides the digitized voltage to a MC68000 microprocessor. The microprocessor 

accomplishes the required log functions, diode linearization, frequency response, and other 

mathematical functions. 

The PPM can measure the power in both single and repetitive pulses as well as the power in a CW 

signal. Power measurements are presented on an Electro Luminescent (EL) screen to display both 

alphanumeric and graphic information. Modes of operation are indicated both by information on the 

display and by LED lights on the front panel. Changes in mode or test parameters can be accomplished 

with the front panel keypad or, for some operations, the large spin knob on the front panel, which can 

be used as an analog adjustment for certain parameters. 

GPIB (IEEE Bus) setup and measurement operation are standard in the 8500A power meters. It enables 

various other functions, such as reporting of errors, malfunctions, operational status, and self test 

diagnostics. 

The Model 8501A has a single detector input; Model 8502A has dual detector inputs for making ratio 

measurements. All technical and operation descriptions in this manual apply equally to both models 

unless otherwise stated. 

Performance specifications for the Series 8500A are in Sectio n 1.2. Detector specifications are 

contained in Appendix D. Options, if any will be detailed in Appendix E. 

Power requirements are 100/120/220/240 Vac ±10%, 48-400 Hz. See Section 2.2 for Safety Precautions 

and details to set the voltage and install the correct fuse for the area in which the instrument will be 

used. 

Manual 20790, Rev. C, November 1998 1-1 



1.1.1 Environmental Requirements 

Series 8500A power meters are type tested to MIL-T-28800E, Type III, Class 5, Style E for Navy 

shipboard, submarine, and shore applications except as follows: 

• Operating temperature range is 0 °C to 50 °C (calibrator operating temperature range is 5 °C to 

35 °C). 

• Non-operating (storage) temperature range is -4 0°C to +7 0°C. 

• Relative humidity is limited to 95% non-condensing. 

• Altitude and EMI requirements are not specified. 

1.1.2 Items Furnished 

In addition to options and/or accessories specifically ordered, items furnished with the instrument are: 

1 ea. - Power Cord 

1 ea. - Detachable Detector Cable (for Model 8501A), or 

2 ea. - Detachable Detector Cables (for Model 8502A) 

1 ea. - Operation and Maintenance Manual 

1.1.3 Items Required 

The 8500A requires an external power detector; see Appendix D for power detector specifications. 

1.1.4 Tools and Test Equipment 

1.1.5 Cooling 

1.1.6 Cleaning 

No special tools are required to operate the Series 8500A. Test equipment required for calibration or 

performance verification is described in Chapter 4. 

No cooling is required if the instrument is operated within its specified operating temperature range 

(0 to 50 °C). 

The front panel can be cleaned using a cloth dampened with a mild detergent; wipe off the detergent 

residue with a damp cloth and dry with a dry cloth. Solvents and abrasive cleaners should not be used. 

1.1.7 Receiving Inspection 

Use care in removing the instrument from the carton and check immediately for physical damage, such 

as bent or broken connectors on the front and rear panels, dents or scratches on the panels, broken 

extractor handles, etc. Check the shipping carton for evidence of physical damage and immediately 

report any damage to the shipping carrier. 

Each Giga-tronics instrument must pass rigorous inspections and tests prior to shipment. Upon receipt, 

its performance should be verified to ensure that operation has not been impaired during shipment. The 

performance verification procedure is described in Chapter 5 of this manual. 

1-2 Manual 20790, Rev. C, November 1998 


Introduction 

1.1.8 Returning an Instrument 

If you are returning an instrument to Giga-tronics for any reason, including service, first contact 

Giga-tronics Customer Service at (800) 444-2878 or Fax at (925) 328-4702 so that a return 

authorization number can be assigned. You can also contact Customer Service over their e-mail address 

repairs@gigatronics.com. 

To protect the instrument during reshipment, use the best packaging materials available. If possible use 

the original shipping container. If this is not possible, a strong carton or a wooden box should be used. 

Wrap the instrument in heavy paper or plastic before placing it in the shipping container. Completely 

fill the areas on all sides of the instrument with packaging material. Take extra precautions to protect 

the front and rear panels. 

Seal the package with strong tape or metal bands. Mark the outside of the package “FRAGILE — 

DELICATE INSTRUMENT”. If corresponding with the factory or local Giga-tronics sales 

office regarding reshipment, please reference the full model number and serial number. If the instrument 

is being reshipped for repair, enclose all available pertinent data regarding the problem that has been 

found. 




1.2 System Specifications 

Frequency Range 

30 MHz to 40 GHz depending on detectors 

(See the Detector Specifications in Appendix D) 

Power Range 

(Direct input to detector): 

Pulse Mode: 

CW Mode: 

Absolute Maximum Limit: 

-20 to +20 dBm 

-40 to +20 dBm 

+23 dBm (200 mW) 

Accuracy 

Calibrator Power Uncertainty 

(at 0 dBm): 

The uncertainty of microwave power measurements depends on 

several factors, the most important is the effective mismatch of 

both the power detector and the RF source. Excluding mismatch 

effects, the measurement uncertainties of the instrument and its 

power detectors are as follows: 

±1.5% (0.065 dBm) 

Linearity after Automatic 

Calibration: 

±3% (at stable temperature) 

Temperature coefficient of 

linearity at ambien t±5 °C, CW 

and Peak, typical: >-10 dBm negligible, 0 to 50 °C 

Introduction 

Trigger Delay 

Range: 

Resolution: 

Accuracy: 

0 to 200 ms, using either the Data Entry keyboard or the spin 

knob 

0.1 ns 

0to10ms,±0.2%±1ns;10msto5ms,±0.1%;5msto 

200 ms, ±0.01% 

Triggering Modes 

Internal: 

-20dBmto+16dBmlimitedto>2dBand


Auxiliary Inputs/Outputs 

Monitor: 

Analog Output Coefficient: 

Offset: 

Trigger Input: 

RF Blanking: 

V PROP F: 

Provides a voltage proportional to the detected RF envelope. 

Rise time is typically 20 ns, output impedance is nominally 50 

ohms. 

100 mV/dB ±0.5 mV (0 V = 0 dBm) 

±10 mV 

TTL 

TTL open collector low during zeroing. Used to control power 

source. 

(V/GHz) Allows direct entry of frequency from RF power sources 

equipped with a VpropF output. 

GPIB Interface: Per IEEE STD 488-1978 

GPIB Indicators: 

REM, TLK, LSN, SRQ, LLO 

Remote Operation 

Direct Plot Output: 

GPIB Address: 

IEEE Interface Functions: 

Complete setup and measurement capabilities accessible via 

GPIB (IEEE 488). Reporting of errors, malfunctions, operational 

status, and self-test diagnostics available through serial poll 

capability. 

Outputs hardcopy pulse profile plots, with time, date and part 

identification, to a GPIB plotter. 

Selectable from front panel 

SH1, AH1, T6, L4, SR1, RL1, PP0, DC1, DT1, TE0, LE0 

General Specifications 

Stored Setups: 

Power-On Self-Test (POST): 

Reset Control 

(rear panel): 

Saves settings at power down, and has 10 additional setups in 

non-volatile memory. 

POST is optionally performed at any time. A diagnostic code 

indicates the cause and location of any errors. 

Returns the instrument to preset (default) condition. 

Design and Construction: To the intent of MIL-T-28800C, Type III, Class 5, Style E or F, 

Color R 

Power Requirements: 100, 120, 220, or 240 Vac ±10%, 50, 60, or 400 Hz ±5% 

Power Consumption: 

Operating Temperature: 

Non-operating Temperature: 

Approximately 100 VA 

0 to 50 °C (32 to 122 °F) 

-40 to +65 °C (-40 to +149 °F) 



Introduction 

Operating Humidity 

(without precipitation): 95%, ±5% to 30 °C 

75%,±5%to40°C 

45%,±5%to50°C 

Dimensions: 

Bench Mount: With Feet: 148.3 x 425.7 x 355.6 mm (5.84 x 16.76 x 14.00 in.) 

Without Feet: 132.6 x 425.7 x 355.6 mm (5.22 x 16.76 x 14.00 in.) 

Rack Mount: 

Weight: 

132.6 x 482.6 x 355.6 mm (5.22 x 19.00 x 14.00 in.) 

Conforms to EIA RS-310 Standard for a 19-inch rack. 

Model 8501A: 12 kg (26 lbs) 

Model 8502A: 13 kg (28 lbs) 

Depending upon requirements, the following software versions and enhancements apply (See Table 1-1). 

Table 1-1: 8500A Functions Related to Software Versions 

S/W Version Sound Works Fast Analog 

2.10A YES 

S-Mode 

(FAA) 

Menu Wrap 

2.11A 

2.13A YES YES 

2.14A YES YES YES 




1.3 Default Settings 

Factory-programmed settings of various user definable functions have the following defaults whenever 

there have been no changes made in the settings by the operator during any testing routines. 

Function 

Averaging 

Internal Trigger Level (A & B) 

Frequency 

Offset 

Cursor Delay (A & B) 

Start Delay 

Delay Window (A & B) 

Reference Power Level (A & B) 

Reference Delay (A & B) 

Cal Factor 

Mode 

Trigger Mode 

Default Setting 

CW: 4 samples; Peak: 4 samples 

-10 dBm 

1.00 GHz 

0 dB 

1.0000 microseconds 

0.0000 nanoseconds 


0 dBm 


0 dB 

Channel A, CW power, dBm 

Channel A, Internal 

Pulse Width Start 50% 

Pulse Width End 50% 

Rise Time Start 10% 

Rise Time End 90% 

Fall Time Start 90% 

Fall Time End 10% 

Marker 1 2.5% (A and B) 



Marker 4 90% (A and B) 

The following settings are not affected by power-on, initialization, and setup store or recall: 

Maximum Power 

Minimum Power 

+20.5 dBm 

-45.0 dBm 

Autoscale Average Number 4 

Autoscale Initial Delay 75 µs 

Plotter Address 6 

PPM Address 4 

Source of Frequency Correction 

Frequency Display 

a) User supplied (as input, default = 1GHz) 

b) VpropF - parameters not subject to store/ 

recall or initialization 

c) Cal Factor - not subject to store/recall or 

initialization 

Displayed 



2 

Operation 

2.1 General 

The Series 8500A Peak Power Meters are very simple to operate. You only need to follow the instructions 

given in the prompts and menus shown in the display window to set up the parameters for making a 

measurement. Eleven levels of operational menus are available. Each can be accessed with the MENU 

key. The type of measurement (Peak or CW) being made will also be shown in the lower right corner of 

the display to identify the mode in use. 

Along with the menus and prompts in the display, the power meters produce audible clicks and beeps to 

indicate the occurrence (or non-occurrence) of certain events during setup and testing. The tones are 

defined as follows: 

Click: 

When a key is pressed and a click is heard, this means that the key is active and its 

function will be included in the parameters being entered. If no click is heard, the 

key is not active and not performing any function at that time. 

Beep: 

A single beep indicates that the calibration, zeroing, or self-test functions have 

successfully completed when they are performed. A double beep means that the 

function failed to complete. The discussion of these functions later in this chapter 

will detail what problems might cause the function to fail. 

There is a volume control on the rear panel of the instrument. It adjusts the audio tones to a comfortable 

level, or the audio can be turned off if desired. 

2.2 Installation 

☛ NOTE: In the remainder of this chapter except where specified as the Model 8501A or 

8502A, the instrument may be referred to as the PPM (Peak Power Meter). 

The unit is set at the factory for operation at the normal supply voltage for the country in which it is 

sold. The input frequency must be 50, 60, or 400 Hz ±5%. The combination of the module and 

transformer design allows instrument operation of 100/120 volts with a 2.0 A Slo-Blo fuse, or 220/240 

volts with a 1.0 A Slo-Blo fuse. 

WARNING 

Before applying ac power to the instrument, be sure that the instrument is set for 

the correct line voltage and that the fuses are of the correct rating. 

Figure 2-4 illustrates the rear panel. Before operating the instrument, make sure the input voltage is 

correctly set and that the fuses are compatible with the applied line voltage. 

Manual No. 20790, Rev C, November 1998 2-1 



☛ NOTE: The 8500A may be furnished with the PC-oriented voltage selector and fuse holder 

described next, or the VDE-approved fuse holder described in the following pages. Refer 

to the appropriate type of voltage selector and fuse holder for your power meter. 

CAUTION 

The instrument may be damaged if you turn it on while the voltage selector and 

fuses are incorrect for the applied line voltage. 

The power meter is supplied with a three-conductor NEMA type power cord for connection to the power 

source and safety ground, as illustrated in Figure 2-1. The current carrying conductor is black and its 

return is white. The green wire of the power cord is for connection to earth ground. The instrument will 

be properly grounded if the plug is connected to a properly installed three-prong receptacle. If a 

three-prong to two-prong adapter is used, be sure that the pigtail lead of the adapter is earth-grounded. 

WARNING 

The safety ground is connected directly to the chassis. If a 3-to-2 wire adapter is 

to be used, be sure to connect the ground lead from the adapter to earth ground. 

Failure to do this could cause the instrument to float above ground, posing a shock 

hazard. 

EARTH GROUND 

LINE 

NEUTRAL 

LINE 

NEUTRAL 

EARTH GROUND 

Figure 2-1. Power Connector 

2-2 Manual No. 20790, Rev C, November 1998 


Operation 

2.2.1 PCB-Oriented Voltage Selector and Fuse Holder 

The number on the selector card, visible through the window, indicates the nominal line voltage to which 

the power meter must be connected. 

The line voltages and fuse ratings are: 

Line Voltage 

Fuse Rating 

100/120 Vac, ±10%, 50, 60 or 400 Hz ±5% 1.0 AMP Slo-Blo 


To select a different operating line voltage and fuse, refer to Figure 2-2 and proceed as follows: 

1. Open the cover door, rotate the fuse-pull to the left, and remove the fuse. 

2. Select the operating voltage by orienting the PC board so that the correct voltage label is on the 

top left side. 

3. Push the board firmly back into the module slot. 

4. Rotate the fuse-pull back into the normal position and reinsert the fuse into the holder. Use care 

to select the correct fuse value. 

Operating voltage is shown 

in the module window 

Figure 2-2. PCB Voltage Selector and Fuse Holder 




2.2.2 VDE Type Voltage and Fuse Holder 

The VDE-approved voltage selector and fuse holder are contained in a covered housing directly above the 

ac power connecter. 

The line voltages and fuse ratings are: 

Line Voltage 

Fuse Rating 



To gain access to the voltage selector and fuse, open the cover with a small screwdriver or similar tool 

and proceed as follows: 

To change the voltage setting: 

Use the same tool to remove the voltage selector (a small barrel-shaped component marked with voltage 

settings). Rotate the selector so that the desired voltage faces outward and place the selector back in its 

slot. Close the housing cover; the appropriate voltage should be visible through the window (see 

Figure 2-3). 

To replace the fuse: 

With the housing cover open, pull out the small drawer on the right side of the housing (marked with an 

arrow) and remove the old fuse. Replace with a new fuse, insert the drawer and close the housing cover 

(see Figure 2-3). 

Figure 2-3. VDE Voltage Selector and Fuse Holder 



Operation 

2.3 Rear Panel Description 

The Series 8500A power meter rear panel controls and interface connections are described in this section. 

The boxed numbers in the diagram correspond to the boxed numbers in the description. The Model 

8501A will have single-channel inputs while Model 8502A will have Channel A and Channel B inputs as 

shown in Figure 2-4. 

Figure 2-4. Model 8502A Rear Panel 

1 Input Power 

and Fuse 

Refer to Section 2.2 for the details to select the correct input voltage and fuse. 

2 Monitor Output This output connection interconnects to a test instrument such as an oscilloscope to 

externally monitor the detected signals entering the PPM. The Model 8502A has a 

monitor input for Channel A and Channel B. 

3 Analog Output This connector outputs 100 mV/dB signal to interface the PPM with the 

Giga-tronics Model 8003 Precision Scalar Analyzer for making swept peak power 

measurements (see Measuring Peak Power Under Swept Conditions in Section 2.14). 

The Model 8502A has an analog input for Channel A and Channel B. 

CAUTION 

When using the PPM in the 1018B Emulation Mode, it should be kept in mind that 

the 1018B instrument has a 10 mV/dB analog output while the PPM has 

100 mV/dB. If the 10 mV/dB output of the 1018B is required, a 10:1 resistive divider 

network should be employed to reduce the PPM’s 100 mV/dB output. 




4 Detector Input These channel A and B inputs (single input in the 8501A) will be hole cover plates 

unless Option 03 (Rear Panel Connection) has been ordered. With Option 03, the 

Detector Input and Calibrator will be relocated from the front to the rear panel. The 

Calibrator connection will be above the Serial/Code number label on the right side 

of the rear panel. 

5 GPIB Interface This is the interface connection for controlling the instrument through the GPIB 

(IEEE bus). 

6 FREQ Input This is the voltage-proportional-to-frequency (VpropF) input connection that 

receives the Frequency Reference or V/GHz (V α F) output signal from an external 

signal generator. This signal provides frequency information to the PPM for detector 

frequency response correction when required. 

7 TRIG Input - 

TTL 

This connection interfaces a TTL signal source to provide an external trigger when 

this mode of operation is selected. 

8 SYNC Output This output connection provides access to the sample pulse for synchronizing the 

PPM to an external counter. 

9 RF Blanking 

Output - TTL 

This output interfaces a blanking TTL signal to turn off the external RF power 

signal source when you want to autozero or calibrate the detectors. It is at a TTL 

high level during execution of these functions. 

10 Reset This control resets the PPM to its initial power-on condition without having to turn 

off the instrument. 

11 Volume Control This control adjusts the volume level of the audio tones generated by the PPM. The 

audio can be turned off with this control. 



Operation 

2.4 Front Panel Description 

The front panel controls, display, and connections are described in this section. The boxed numbers in 

Figure 2-5 correspond to the boxed numbers in the description. The Peak, CW, and Graph keys in both 

power meter models, and the Detector Select A and B keys of the Model 8502A contain lights in the 

center of the buttons to indicate when the functions are active. 

2 6 7 8 13 17 

Peak Power Meter 

Model 8502A 

7 8 9 

4 5 6 

Clear 

GHz kW 

ms 

Calibrator 

1GHz 

1 

2 3 

dB W 

µs 

On 

Off 

LL0 

 

F1 F2 F3 

 

Bksp 

GPIB 

LSN REM 

Ready 

TLK SRQ 

New Data 

dBm mW 

0 . _ 

ns 

Pulse/ 

Cursor Menu Freq Mem 

Detector Select 

A B 

Peak CW Graph 

Autoscale 

Detector Input 

A 

B 

1 

3 4 5 9 

14 

10 11 12 15 16 

Figure 2-5. Model 8502A Front Panel 

1 Power This is the push-on push-off ac power switch to the PPM. 

2 Display This is an Electro Luminescent (EL) alphanumeric and graphic display screen. It 

presents data and shows pulse waveform profiles. 

3 GPIB 

Indicators 

4 F1, F2, F3 

Directional keys 

Backspace 

5 Ready, New Data 

Indicators 

These LEDs indicate whether the PPM is under local or remote control and the 

current GPIB status (REM = remote control on, LSN = listen, TLK = talk, SRQ = 

service request, and LLO = local lockout.) 

The F1 (up) and F2 (down) directional keys are used in the Graph Mode to move the 

cursor (∆ icon) up and down to select any pulse or cursor parameters that are to be 

changed. The F3 (backspace) key is for correcting entered text or numbers. 

A secondary function of these keys is to select menu functions as the various menus 

are displayed. 

These LEDs flash whenever the system is receiving a trigger. If the Ready light is 

steadily on and the New Data light is off, it would indicate that a trigger was not 

being received. 

6 Data Entry Use this 12-button keypad to enter parameter data when instructed in the applicable 

procedure. 




7 Clear The CLEAR key exits from a menu, but it clears erroneous entries while entering 

data. 

8 Units: 

ns/dBm mW 

µs/dB W 

ms/GHz kW 

This key enters pulse timing parameters in nanoseconds. The dBm mW function 

enters a power parameter in either dBm or milliwatts. 

This key enters pulse timing parameters in microseconds. The dB W function enters 

a power parameter in either dB or Watts. 

This key enters pulse timing parameters in milliseconds. The GHz kW function 

enters a frequency in GHz or (with offsets) a power parameter in kilowatts. 

☛ NOTE: Each of the unit keys have a secondary function. At various points in these 

instructions, the procedures will state to press any units key. This is to enter a parameter 

without units (average number), to enter units other than those listed above (start voltage), 

or to start a function. 

9 Pulse/Cursor/ 

Marker 

This key is active only in the Graph Mode. Pressing the key cycles the PPM through 

the three sub-modes: Pulse, Cursor, and Marker. The Cursor sub-mode is convenient 

for changing the time base parameters, scaling, trigger level, and cursor position. 

The Pulse sub-mode displays the rise time, fall time, and pulse width of the current 

pulse. The Marker sub-mode displays the time between four user-defined power 

levels on the pulse. 

10 Menu The MENU key enables access to the eleven main menus of the PPM. Depending on 

the mode of operation, other keys can display sub-menus that pertain to the 

particular function of that key. However, the MENU key will cause the routine to 

step through each of the main menus each time it is pressed. As an example, if it 

were pressed three times, then Menu 3 would be displayed. 

Appendix B contains a description of each menu that will be accessed at each 

keystroke of the MENU key. Wherever possible, commands or user selections that 

would be used more often are located at the top of the menu structure (Menu-1 

through Menu-4). Less commonly used menus are located toward the bottom of the 

menu structure (Menu-5 through Menu-11). 

11 Freq This key enters the signal frequency for the channel A and B detectors. When the 

PPM default setting is used, all that is required is the entry of the frequency of the 

specific signal being tested. 

If the PPM is in the Cal Factor or V/GHz setting, the FREQ key will allow you to 

change these parameters by following the prompts. 

12 MEM This key activates three memory menus. Press the key once to display memory 

Menu-1. Press the key twice to display memory Menu-2, and three times for 

memory Menu-3. Press [CLEAR] to return the routine to the Data Display mode. 

The memory menus control the non-volatile setup memories. The contents of the ten 

memory locations can be stored, recalled, initialized, and displayed. The menus also 

give you the option to return to the current test setup (the test in use just before the 

MEM key was pressed), as well as the option to return to the initial power-on status. 



Operation 

See the Non-Volatile Memory discussion in Section 2.17 for more information on 

the PPM memory capabilities. 

13 Spin Knob The spin knob changes the value of selected parameters. The usability of the knob is 

indicated in the display by the appearance of a delta symbol (∆) next to the name of 

the parameter of interest. For instance, when in the Peak mode, a Cursor Delay entry 

will cause the delta symbol to appear next to DLY in the power reading display. 

This means that the spin knob can be used to change the Cursor Delay setting. 

14 Detector Select 

A or B 

(8502A only) 

15 Peak, CW, 

Graph 

These keys select which channel should display data on the Model 8502A display. 

They also tell the instrument which channel a trigger level entry is intended for. In 

the CW and Peak Modes it is possible to display measurements for either channel A 

or B, or both at the same time. In the Graph Mode, only one channel at a time can 

be viewed. 

These mode keys select whether the PPM will be used for CW or Peak power 

measurements. GRAPH is used when making Peak power measurements to allow the 

graphic display of the detected pulse and easy determination of pulse timing factors. 

In addition to the readout display indications, the selected mode is identified by 

which LED in the center of the PEAK, GRAPH, and CW keys is lit. If the Model 

8502A is being used for dual channel operation and all of the mode LED’s are out, 

then it is in the Ratio Mode (see the Power Ratio Measurement Procedures in 

Section 2.10.5). 

When the 8502A Ratio Mode is in use, the A and B keys call up a menu so that the 

type of signal (CW or Peak) can be specified for the selected channel. This is useful 

for determining the ratio between a CW and a Peak signal. For example, a radar 

TWT might have a pulsed output but its input could be CW. To measure its gain, the 

Peak output would have to be divided by the CW input. The 8502A does this 

instantly and automatically. 

16 Detector Input These receptacles provide the input from the A and B channel detectors in the 

Model 8502A. The Model 8501A has a single input. 

17 Calibrator The CALIBRATOR connection performs an amplitude response calibration of the 

detector from -30 dBm to +20 dBm, as well as standardizing the absolute power 

level readings (see the Self-Calibration Procedure in Section 2.7). 




2.5 Operation 

Single-channel operation is essentially the same dual-channel for standard peak power and CW 

measurements. The single channel 8501A does not have a ratio measurement capability. The following 

instructions define the operation of both instruments. If a Model 8501A is being used, ignore references 

to A and B keys, distinctions between the A and B channels, and reference to two detectors. The single 

channel of the 8501A is channel A for definition purposes. If the instructions require that a distinction be 

made between the two instruments, the specific model number will be given rather than PPM. 

2.5.1 Power On Self-Test (POST) 

1. Before turning on the power to the PPM, be sure that it is set for the correct input voltage. 

Procedures for setting the operating voltage are given in Section 2.2. 

2. Connect a detector (detector) to the DETECTOR INPUT at channel A, using the Giga-tronics 

detector cable (P/N 16956-XXX, where XXX defines the specified length of the cable) supplied 

with the system. If a Model 8502A is to be used, detectors should be connected to channel A and 

B inputs for dual channel operation. 

To connect the cable to the detector housing, pull back on the metal sleeve at the detector end of 

the cable, align the red dots, and make the connection. To connect the other end of the cable to 

the front panel DETECTOR INPUT receptacle, again pull back the metal sleeve, align the red dots 

on the cable and input receptacle, and make the connection. 

☛ NOTE: The detector must be connected to the Calibrator connection on the front panel, to 

a 50-ohm termination, or to a signal source before initiating the POST function. 

3. Turn on the power by pressing the power switch on the front panel. The PPM will perform a 

self-test to verify that it is operating properly. 

The self-test is not identical to the one performed by selecting [MENU] (11) [F2], or by sending the 

SELT command over the GPIB. The POST will not report errors 5 or 6 because you may not have 

removed the RF power from the detectors, or error 10 because it sometimes fails erroneously soon after 

power on (see Self-Test Failure Indications in Section 2.15). 

The PPM will automatically return to the last setup before the instrument was powered off. 

2.5.2 Warm Up Time and Temperature 

When initially operating the PPM, it is common to see a prompt on the display stating 

RECAL: dT XXX DEGS-C. 

The number of degrees shown is the difference between the present temperature of the detector and the 

temperature at which it was last calibrated. 

The prompt occurs only if the change in detector temperature is more than 5 °C. When this prompt is 

displayed, sufficient time should be allowed for the instrument to warm up so that accurate readings can 

be taken. Variations of less than 5 °C from the calibration temperature do not result in a temperature 

prompt display because minor temperature changes in the detector are monitored and compensated by the 

68000 microprocessor. 

If the PPM continues to display the temperature prompt after 30 minutes warm up, or if the room 

ambient temperature changes by more than 5 °C, a Self-Calibration will be required (see the Self 

Calibration Procedures in Section 2.7). 



Operation 

2.6 Mode Selection 

Follow these procedures to select the desired operating mode. The modes are CW, PEAK and GRAPH. 

Throughout this chapter, you will be instructed to press the MENU and MEM keys. The instruction may 

be followed by a number in parenthesis. This number corresponds to the menu number and indicates the 

number of times you need to press the key to reach the necessary menu. 

2.6.1 CW Mode 

If in the Peak or Graph mode, press [CW] to access the CW Mode. 

If a menu is being displayed and you want to exit it and go to the CW Mode press [CLEAR] [CW]. 

If the 8502A is in the Ratio mode, selecting CW will cancel RATIO and the 8502A will display the CW 

power of channel A. 

In certain instances the option will be given to select the CW Mode if there is some reason that another 

mode is not operating properly. For example, if a trigger had not been provided as required in the Peak 

Mode. The purpose is to allow an escape from erroneous modes of operation. 

Very few adjustments or menu selections are required to set up the unit for CW measurements. The two 

major settings that must be specified are defined as follows: 

Frequency 

Press [FREQ] to select the operating frequency at which the power will be measured. Normally, the PPM 

automatically adjusts for detector frequency response variations by using the factory measured frequency 

response data stored in the PROM in the detector housing. Other options are available as detailed in 

PROM Frequency Correction Section 2.8.2. Not compensating for the frequency response of the detector 

could result in an error in the power measurement reading. 

CW Averaging 

This setting selects how many samples of the signal being measured will be taken and averaged to reduce 

noise effects at low power levels. To adjust the averaging number, press [Menu] (2) [F1]. A number 

between 1 and 999 averages must then be entered. The number of averages presently in effect is not 

indicated until the averaging menu has been entered. 

Low Power Level Measurements 

When the PPM is used in the CW mode for power levels below -30 dBm, its dynamic range is extended 

to below -40 dBm. Under low power testing conditions it is necessary to observe the correct auto-zeroing 

procedures to obtain the highest measurement accuracy. Zeroing should be done more often in 

environments where temperature changes are more drastic. See the Auto-Zero procedures in Section 2.7.3. 

2.6.2 Peak Mode 

While you are in the CW or Graph Mode, press [PEAK] to access the Peak mode. 

If a menu is displayed and you want to exit and go to the Peak mode, press [CLEAR] [PEAK]. 

After this, follow the trigger setting guidelines given below. Lack of a trigger can freeze the display. To 

exit either of these situations either the trigger can be set, or the CW Mode can again be accessed by 

pressing [CW]. 

To make measurements in the Peak or Graph Mode, first ensure that the system is receiving a trigger 

signal that will drive its timebase and crystal-based delay generator. The delay generator accurately 

places a sampling window at the desired time on the pulse to be measured. The different triggering 

methods are detailed below. 




Internal Triggering 

The PPM can generate its own internal trigger from the detected RF video envelope at the detector 

output. This triggering mode requires that the power of the RF pulse be greater than the internal trigger 

level. The trigger level is an adjustable threshold at which the leading rising edge of a pulse will cause 

the PPM to take a reading. The precise time at which a reading is taken following the trigger is 

determined by the delay generator. This function of the PPM is called Cursor Delay. See the Cursor 

Delay functions in Section 2.8.8. 

There are two trigger amplifiers in the PPM, one for the range -20 dBm to -10 dBm and another for the 

range -10 dBm to +16 dBm. Selecting trigger levels in the lower range (below -10 dBm) can cause the 

trigger to be delayed on the order of 100 ns due to the filtering required to improve trigger stability at 

these low levels. The absolute accuracy of the trigger level is about ±1/2 dB near the top of these ranges, 

but degrades to about ±2 dBm near the bottom. 

Normally, the Trigger Level is set at -10 dBm (default). The internal trigger level can be adjusted by 

pressing [MENU] (1) [F1]. A trigger level value between -20 and +16 dBm can then be entered. 

If there is no RF pulse present at the detector input or if the pulse amplitude is too low, the PPM will not 

internally trigger. When this occurs the display will freeze, the New Data light will not be lit, and the 

Ready light will not be on. 

If a Model 8502A is being used, the routine will ask whether internal triggering is to be driven by inputs 

from channel A or channel B. Press the appropriate Detector Select [A] or [B] key. To select the Internal 

Trigger Mode and set the level press: 

8501A: [MENU] (1) [F1] [nn.nn] [UNITS] 

8502A: [MENU] (1) [F1] [A] (or B) [nn.nn] [UNITS] 

(nn.nn = selected trigger level numbers) 

Autoscaling changes the internal trigger channel to the displayed channel. 

External Triggering 

For some test routines it may be desirable to provide an external trigger to the system. This can be 

especially useful if the trigger pulse from the external source leads the RF pulse at the detector input by a 

small amount of time. Readings can then be taken just prior to the arrival of the RF pulse, allowing close 

inspection and measurement of the pulse leading edge. 

To use the External Trigger Mode, connect a BNC cable from the TTL sync pulse output of the system 

under test (or pulse generator) to the Ext Trigger input on the rear panel of the PPM. To select the 

External Trigger Mode, press [MENU] [F2]. Correct operation of the External Trigger Mode can be 

verified by noting that the Ready and New Data lights on the front panel are flashing. 

☛ NOTE: If you attempt to operate in the External Trigger Mode without supplying the 

required trigger as described above, the display will freeze, the Ready light will be on, and 

the New Data light will be out. 

To select External Trigger, press [MENU] (1) [F2]. 



Operation 

2.6.3 Graph Mode 

The Graph Mode of the PPM provides graphic capabilities for the display, plotting, and analyses of RF 

pulse profiles. Most instrument pulse parameters can be set and changed directly from information 

presented in menus. Features are available which allow measurement of commonly required pulse 

parameters such as rise time, pulse width, and so forth. 

When the system is operating satisfactorily in the Peak or Graph Mode, it is possible to toggle back and 

forth between the two modes by pressing [PEAK] or [GRAPH] whenever desired. The only exception to 

this is when an 8502A is being used in the dual channel mode of operation since the Graph Mode does 

not allow dual channel operation. If a dual channel function is being used and it is desired to switch to 

the Graph Mode, single channel operation must first be selected. See Dual Channel Operation in 

Section 2.10. 

The ability to toggle back and forth between Peak and Graph Modes is useful for a number of reasons. 

For example, in the single channel Peak Mode, the display produces large distinct power read-out 

characters that can be read from a distance (see Figure 2-6). In addition, while in the Peak Mode, the 

current frequency being used for the test is directly visible on the display. In the Graph Mode, the display 

is primarily for inspection of the pulse profile and the frequency is not displayed to allow room on the 

display for other important pulse profile parameters (see Figure 2-7 for a typical Graph Mode display). 

All operating parameters such as trigger mode, frequency, and cursor delay are maintained in both the 

Peak and Graph Modes. The Graph Mode can place the cursor at a specific point on the pulse, and then 

the PEAK key can be pressed to see the power reading using the large readout characters. 

Selecting the Graph Mode: 

If in the Peak, CW Mode, or Ratio Modes (previous Graph or Peak Mode settings will apply), press 

[GRAPH]. If a menu is being displayed and you want to exit to the Graph Mode, press [CLEAR] 

[GRAPH]. Then, to Autoscale the pulse, press [AUTOSCALE] 

☛ NOTE: While in the Graph Mode, the Autoscale function of the GRAPH key will be active. 

Under some conditions, autoscaling cannot take place due to the complex shape of the pulse or other 

timing factors. The PPM will then display only a part of the pulse. The reference level will be correct for 

rectangular pulses. The PPM will not have been able to set an appropriate Delay Window for the pulse. It 

may be possible to subsequently autoscale by changing the initial delay value for autoscaling to be closer 

to twice the actual pulse width for the pulse in question. This is done by pressing [MENU] (9) [F2] 

[n.nnnn] [UNITS]. 

To use the Graph Mode, the triggering selection guidelines discussed Section 2.6.2 must be followed. 




2.7 Self-Calibration and Auto-Zeroing 

The purpose of the PPM’s Self-Calibration function is to ensure that measurement accuracy will be 

maintained despite changes in detectors, changes in detector diode temperature, or other changes that 

might occur in the PPM’s analog circuits. 

During the time the instrument is performing its Self-Calibration routine, the RF output of the 1 GHz 

calibrator is accurately stepped from +20 to -30 dBm. Each step is measured by an internal standard and, 

at each point, the calibrator output power as measured by the RF detector is compared to the standard. 

The power readings are then digitally adjusted by the PPM microprocessor and stored in memory. For 

power levels below -30 dBm, the system relies on the Auto-Zero function as well as the inherent 

repeatability of the detector voltage output versus input power at these levels. (Refer to Section 4.2.7 for 

a complete description of the automatic calibration system.) 

To make any type of power measurements with the PPM it will be necessary to use the appropriate 

calibration and zeroing procedures to ensure the highest accuracy. 

After the instrument has warmed up for 30 minutes and the mode of operation has been selected, a 

detector self-calibration should be performed. In addition, if the ambient room temperature changes more 

than 5 °C from the temperature at which the system was last calibrated, self-calibration should also be 

done. If there has been a change in the temperature of the detector of more than 5 °C since it was last 

calibrated, the difference will be shown. 

2.7.1 Self-Calibration Procedure 

Connect the channel A detector to the 1 GHz Calibrator output. Press [MENU] [F3] to call up the Cal or 

Zero Detectors menu. The menu offers the following choices: 

• F1 to Calibrate the Detectors 

• F2 to Auto-Zero the Detectors 

• F3 to Return to Data Display 

Select F1 for the Detector Self-Calibration. 

☛ NOTE: The CLEAR key as well as F3, can also be used to return to data display. 

The display will show the last date and time the detector was calibrated. To proceed with the calibration, 

press any Units key. The Self-Cal process takes about 50 seconds, during which time the statement 

A (or B) CALIBRATION IN PROGRESS 

will be displayed. 

If a Model 8501A is in use, press [CLEAR] to return the routine to the data display (the last mode of 

operation). If the Model 8502A is being used, press [CLEAR] to bypass the channel A calibration and go 

to the channel B calibration. 

After successful completion of the Self-Cal function, the instrument will go back to displaying data in the 

last mode of operation. With the Model 8502A, either bypassing or successfully completing the channel 

A calibration will take the routine to the channel B calibration. 

Channel B calibration is done in the same manner as the channel A calibration. The date and time of the 

last B channel calibration will be presented, and the option will be given to either press any Units key to 

start the cal procedure or press [CLEAR] to return to the data display. 



Operation 

2.7.2 Self-Calibration Failures 

In the event of a malfunction such as a burned out detector diode or if you forget to connect the detector 

to the calibrator, the Self-Cal function will fail. If this occurs, the following error menu will be displayed: 

A Calibration Error Exists 

Press [CLEAR] to continue 

Press any Units key to repeat cal 

Press [CLEAR] to return the instrument to the last mode of operation. 

Selecting any Units key gives you the opportunity to correct a simple error such as not connecting the 

detector to the calibrator. This can be accomplished, and then the Self-Cal procedure can be repeated. 

See Input/Output & Calibration Failure descriptions in Section 6.3.2 for the procedure to follow if the 

PPM fails the Self-Cal. 

2.7.3 Auto-Zero Function 

To initiate the Auto-Zero function, turn off the RF power to the detector to be zeroed and then press 

[MENU] [F3] to get to the Self-Cal/Auto-Zero menu. Then press [F2] to Auto-Zero and follow the 

displayed prompts. 

If the Model 8502A is in use, channel A must be auto-zeroed before channel B. If desired, channel A can 

be bypassed by pressing [CLEAR] and going directly to channel B. 




2.8 Measurement Procedures 

2.8.1 Frequency Correction, Cal Factor, and dB Offset 

The Frequency Correction and Offset functions enhance measurement accuracy, and compensate for 

detector amplitude and frequency response variations as well as devices residual to the test setup. 

Frequency correction is selected in Menu-3. Three methods of frequency correction are available and will 

be described in detail in this section. These are: 

• PROM Table — User Supplied Frequency (default mode). 

• PROM Table — External Frequency Input (uses the V α F output of the sweeper) 

• User Supplied Calibration Factor — (allows direct entry in dB) 

To select the desired mode, press [MENU] (3) [F3]. 

Then select F1, F2, or F3 respectively, for items a, b, or c. This will determine the functioning of the 

FREQ key of the instrument. 

Whenever a mode is selected that uses the PROM table in the detector assembly for frequency correction, 

the PPM will interpolate between the discrete amplitude correction points stored in the detector PROM. 

This allows entry of frequencies other than those stored in the PROM, and reduces the need for operator 

interpretation and manual correction of power readings. 

All of the information stored in the PROM of the detector currently in use can be reviewed by accessing 

Menu-10 and pressing [F2] for channel A, and/or [F3] for channel B. 

2.8.2 PROM Frequency Correction 

User-Supplied Frequency 

This is the User-Supplied Frequency mode. It is the default mode of the instrument. Factory measured 

frequency correction data is stored in a PROM inside the detector housing, thus eliminating the need for 

you to refer to a frequency correction chart and then make manual adjustments to the system for each 

discrete frequency point. The PROM data is used by the PPM to correct for all of the detector’s 

amplitude variations across its entire frequency range. When the system is first turned on, the PROM data 

stored in the detector is transferred to the main memory of the PPM. 

To select the PROM Table - User Supplied Frequency mode, press [MENU] (3) [F3] [F1]. 

The display will then prompt for the frequency of operation to be entered. The default frequency is 

1 GHz, the same as that of the Calibrator. Press any Units key to complete the entry. 

After selecting the PROM Table - User Supplied Frequency mode, use of the FREQ key allows entry of 

the carrier frequency and gives the microprocessor the ability to correct any detector frequency response 

deviations. 

External Frequency 

The purpose of the PROM Table - External Frequency input function is to allow entry of the operating 

frequency by means of an externally applied voltage. The voltage level will be proportional to the 

frequency, and will be used by the PPM to correct power readings for detector frequency response. 

When this function is active, the RF frequency of a sweep generator or signal source can be changed and 

the PPM will convert the analog voltage input (through the rear panel FREQ Input connection) to a 

digital representation of the frequency. The PPM’s microprocessor uses this information to correct power 

readings according to the frequency correction table stored in the detector’s PROM. 



Operation 

If the sweep generator (sweeper) is equipped with a rear panel output providing frequency information, 

this information will usually consist of an analog voltage proportional to the RF frequency output of the 

sweeper at any given time. Some sweeper manufacturers refer to this voltage as Frequency Reference, 

Volts/GHz (V/GHz), or Voltage-Proportional-to-Frequency (VpropF or V α F). The most common 

coefficients for this output are 1V/GHz and 0.5V/GHz. 

Once the VpropF frequency correction function has been activated, the FREQ key can change the 

parameters for use by the VpropF function. 

To activate the VpropF frequency correction function, perform the following: 

1. Connect a BNC cable from the V/GHz output of the sweeper to the Frequency Input on the rear 

of the PPM. 

2. Press [MENU] (3) [F3] [F2]. 

3. The instrument will then ask for the sweeper V/GHz value (normally 1 or 0.5). Press [n.n] 

[UNITS] (where n.n is volts and UNITS is any units key). 

4. The Sweeper Start Voltage is required next. If the sweeper frequency range is from 2 to 18 GHz 

and the sweeper V/GHz coefficient is 0.5V/GHz, then this value would normally be 2 x 0.5 = 1. 

Press any Units key to complete this entry. 

The above steps set the frequency scaling factor for the PPM so that the analog voltage coming in from 

the FREQUENCY INPUT connection can be interpreted to the correct frequency by the PPM’s 

microprocessor. 

2.8.3 User-Supplied Cal Factor 

If you prefer to use your own detector frequency response correction factors, the PPM provides a means 

to manually correct for any detector frequency response variations (in dB). An example of when this 

could be necessary is if the data stored in the detector’s PROM might be out of date. 

To activate the Cal Factor feature of the system, press [MENU] (3) [F3] [F3]. 

If the dual channel 8502A is being used, you will be asked to select a channel. Select A or B as 

appropriate. 

Next, the value of the desired Cal Factor must be entered in dB. Complete the entry by pressing any 

Units key. 

When using the Cal Factor mode, the frequency of operation is unknown to the PPM. Therefore, the Cal 

Factor will be shown on the display instead of Frequency. This also serves to notify you that this mode is 

in effect. The readout will display the Cal Factor as CF = nn.nn dB. 

☛ NOTE: In the Cal Factor mode of operation the FREQ key alters the Cal Factor (dB), not 

the frequency. 

Offset 

The Offset feature of the instrument digitally offsets the displayed power value within a range of -40 to 

+90 dB. The offset will be in effect whether the measurement is in dBm or linear power in milliwatts. 

The Offset function is useful for two main purposes. (1) It provides the ability to add or subtract minor 

correction factors to correct errors that might be introduced by attenuators or other devices in the test 

setup, and (2) It provides the ability to adjust the reading in high power measurement situations where it 

is desirable to read the correct power directly on the display despite the fact that the unattenuated power 

being tested is well above the measurement range of the detectors. 




In the latter case, a high power coupler is required to attenuate the signal to a level that can be safely 

measured by the detectors (less than +20 dBm). If the exact coupling factor of the coupler being used is 

known, the Offset feature can then be used to subtract it out. Then the display will accurately show the 

high power present at the device under test. However, the detectors only see the coupled power which has 

been attenuated to avoid burning out the detector diode. 

To offset the displayed power reading, press 

8501A: [MENU] (3) [F1] 

8502A: [MENU] (3) [F1] (ch A) or [F2] (ch B). 

After the Offset function has been selected, enter the desired offset in dB and then press any Units key. 

When the Offset function has been activated, an asterisk (*) will appear next to the FREQ indication in 

the display to indicate that an offset is in use. (If the Cal Factor function is in use, the asterisk will be 

next to the CF indication.) 

The display will appear as: 

*FREQ = nn.nGHz or *CF = n.nndB 

2.8.4 CW Power Measurement 

To make a CW measurement be sure that the PPM has warmed up for at least 30 minutes, and then 

perform the following steps: 

1. Select the CW Mode as described in Section 2.6.1. 

2. Self-Calibrate the PPM as described in Section 2.7. 

3. Determine that the power range to be measured will not exceed the maximum power capability 

of the instrument (less than +23 dBm). If it will, connect an attenuator or coupler to the output 

of the device under test to bring the power down into the range of the PPM, and use the 

attenuator or coupler output as the measurement point for the detector attachment. If in doubt, 

use a 10 dB attenuator. This should prevent a mild overload that might result only in detector 

degradation rather than burn out. 

4. Be sure the RF power of the source is completely OFF. 

5. Connect the detector to the power source being measured. 

6. Auto-Zero the detector by pressing [MENU] (1) [F3] [F2] [UNITS], or, if only channel B of a 

Model 8502A is to be zeroed, press [MENU] (1) [F3] [F2] [CLEAR] [UNITS]. 

A beep indicates that a successful auto-zero has been accomplished. A double beep indicates 

either there was RF power present at the detector input or there could be a failure. If a failure is 

suspected, then run the Self-Test procedure in Section 2.15. 

7. Upon successful completion of the auto-zero function, turn on the RF power of the source to be 

measured. 

8. Take into account the detector frequency response so that an accurate reading can be made at the 

frequency of operation. If the External Frequency mode (i.e. PROM Table and Sweeper Back 

Panel) is being used, this step is unnecessary. (See PROM Frequency Correction in 

Section 2.8.2). The keystrokes are [FREQ] [nn.nn] [GHz] 

If the PPM is in the PROM Table - User Supplied Frequency mode, nn.nn is the Carrier 

Frequency in GHz. If the PPM is in the User Supplied Calibration Factor mode, nn.nn is the Cal 

Factor in dB. 

9. If a coupler or attenuator is being used at the detector input, enter the attenuation value as a 

positive offset. For example, if an attenuator with a value of 30.2 dB at the frequency of 



Operation 

operation were being used, the required offset would be entered as follows: 

8501A: [MENU] (3) [F1] 

8502A: [MENU] (3) [F1] (ch A) or [F2] (ch B). 

10. Enter the value of the offset in dB, followed by the dB Units key: 

[30.2] [dB] 

The PPM will now be reading CW power, and the display will look something like: 

A: +35.26 dBm 

*FREQ=10.78 GHz CW 

☛ NOTE: +35.26 dBm represents the power at the input of the attenuator which is connected 

to the detector input. The actual power at the detector input would be +35.26 - 30.2 = 

+5.06 dBm. 

11. Select the number of samples to be taken to arrive at an average reading (default is 4 readings). 

Press [MENU] (2) [F1]. 

12. Enter the desired number followed by pressing any Units key. The number of samples that can be 

taken to arrive at an average can be between 1 and 999. For power levels below -30 dBm, it is 

recommended that more than 100 samples be taken to reduce noise effects. 

13. To change the displayed power reading from dBm to milliwatts or vice versa, press [MENU] (4) [F3]. 

2.8.5 Peak Power Measurement 

Method 1: Peak Mode via Graph Autoscale 

There are several methods that can be used to make Peak Power measurements with the system. The 

easiest method is to use the Autoscaling function in the Graph Mode. The Autoscaling function only 

operates on pulses greater than the selected trigger level. Complex pulse shapes such as double pulses 

cannot always be successfully autoscaled. Methods for these situations will be covered later. 

After the pulse to be measured has been successfully autoscaled, it is only necessary to press [PEAK] and 

the system will read the power at the center point of the pulse. The readout will be displayed in large 

alphanumeric characters. For the following procedure, assume that either a single channel Model 8501A 

is being used or just channel A or channel B of the dual channel 8502A. 

Autoscaling Procedure - Internal Trigger 

1. Connect the detector(s) to the PPM and allow it to warm up for 30 minutes. Then conduct the 

Self-Cal procedure as described in Section 2.7. 

2. When Self-Cal has completed, connect the channel A (or B) detector input to a pulsed signal 

greater than -10 dBm (the default trigger level). Press [GRAPH] to select the Graph Mode, and 

then press it again to start the Autoscaling function. 

When the Autoscaling function is initiated the PPM will change to internal triggering off of the 

displayed channel. Then it will attempt to automatically select the correct Window Delay time 

and Reference Power which will center the pulse on the display. The Start Delay will be set to 

zero. If the signal at the detector RF input is less than the trigger level (or there is no pulse 

present at the input), then the system will not trigger and the following display will appear: 




Waiting for trigger on A (or B) Detector Signal 

F1 for Trig Mode or Level Change 

F3 for CW Data Display 

If you still desire to Autoscale at this point, the easiest thing to do is to increase the RF power 

until the power at the detector input is greater than the trigger level. Then the system will start to 

trigger and the autoscaling process will begin. 

The factory-set default initial delay is 75 µs (pulses wider than 75 µs or pulses less than 75 µs 

apart cannot be Autoscaled when using the default setting), and the default pulse averaging is 

four samples for the Autoscaling function. This can be changed to allow the user to enter a 

different pulse width and averaging number by accessing Menu-9 (press the MENU key 9 times), 

and then following the prompts given in that menu. Once the pulse width and/or pulse averaging 

has been changed from the default setting, the values will remain at the new setting whenever the 

instrument is turned off and on again. The values are not affected by recalling set-ups, nor at 

power-on. 

3. If the previous triggering requirements have been met, the PPM will display the statement, 

AUTOSCALING IN PROGRESS 

4. When the Autoscaling has successfully completed, the pulse profile will be centered in the 

graphics display area on the left side of the window and the top of the pulse will line up with the 

100% tic mark. The Cursor (displayed as a vertical line with spaces just above and below the 

point where it crosses the pulse) will be located at the center of the pulse profile. If all of the 

above has occurred, you can go to the Power Display instructions given below. 

Due to the many varieties of pulse widths, pulse shapes, and duty cycles that might be encountered, it is 

not always possible for the PPM to autoscale. If the failure to autoscale is the result of a pulse being 

present at the 75 µs default setting, the setting can be changed by accessing Menu-9, making the change, 

and then repeating the autoscaling procedure detailed in this section. It is necessary to keep the initial 

delay less than the time from the trigger to the start of the second pulse since the Autoscale routine 

cannot handle multiple pulses in the delay window. 

Autoscaling Procedure - External Trigger 

When pulses are autoscaled on an external trigger, the PPM uses the internal trigger level of the selected 

detector to find the pulse. For this reason, the internal trigger level of the selected detector must be lower 

than the maximum power of the pulse. A good test is to first select internal trigger and verify that the 

PPM is triggering before trying external trigger autoscaling. 

The external triggered autoscale will set the Start Delay to center the pulse in the delay window. 

However, autoscaling may not work properly if the pre-trigger is more than ten times the pulse width. 

1. Press [PEAK]. The PPM will now display the power reading at the Cursor location in large 

alphanumeric characters, similar to the display shown in Figure 2-6. The statement 

DLY = n.nnn µs 

will be at the bottom of the display. This is the Cursor Delay which indicates the time difference 

between the pulse’s initial triggering point and the point where the reading was taken. If the 

triggering method is changed, a given Cursor Delay does not necessarily guarantee that the 

power reading will be taken at exactly the same point on the pulse as it was before. 



Operation 

Figure 2-6. Typical Single Channel Peak Power Display 

2. Press [FREQ] and enter either the RF operating frequency or the Cal Factor in dB. (This step is 

not required if the External Frequency input mode is being used.) 

3. Enter any required offset as described in Section 2.8.3. 

4. If desired, the Peak Averaging can be changed by pressing [MENU] (2) [F2] [nnn] [Units]. 

(nnn = number of samples to be averaged - must be between 1 and 999. Default is 4) 

5. The power will then appear on the display. 

6. To change the time at which the power readings are taken, adjust the spin knob on the front panel. 

Alternatively, Delay entries can also be made through the keypad. After the desired numeric 

entry has been made, pressing the appropriate Units key will enter the delay in either 

nanoseconds, microseconds, or milliseconds. Pressing any UNITS key without entering any 

numbers will cause the cursor symbol (∆) next to the DLY indication on the screen ( CSR DLY = 

N.NN ns) to disappear. This indicates that the keypad and spin knob are inactive and keeps the 

spin knob from being accidentally bumped and moving the cursor to some undesired delay time. 

To reactivate the Delay time entry, press either the up or down arrow key. 

Method 2: Peak Mode - Direct Access 

For the purposes of this procedure, assume that either the single channel 8501A or only channel A of the 

dual channel 8502A is being used. The procedures for channel B of the 8502A are almost the same as 

those for channel A. However, if it is desired to use the Internal Trigger function with channel B, this 

must be selected by using the MENU key as described under Internal Triggering in Section 2.6.2. 

1. Allow the PPM to warm up for 30 minutes, then conduct the Self Calibration procedure (see 

Section 2.5). 

2. Select the Peak Power Mode of operation. Observe the triggering guidelines. If there is no 

external trigger available or if there is any uncertainty as to which method to use, use the 

Internal Trigger (see Section 2.6.2). 

3. To verify that the PPM is in the desired mode and that it is receiving the proper triggering, check 

the following: 

a. The light in the center of the PEAK key should be lit. (If not, this means that the Peak Mode 

has not been entered.) 

b. The Ready and New Data lights should be flashing. (If not, then the system is not receiving 

a trigger. If external was selected and no triggering indication is observed, try the Internal 

Trigger function. The RF pulse power level must be greater than -10 dBm.) 

4. Once Step 3 has been successfully accomplished, the PPM should be taking readings in the Peak 

Power Mode. However, the cursor might not be positioned on the specific pulse of interest at this 




time. 

The easiest way to ensure that all of the Peak Mode settings are at their default values is to 

select Peak operation after initializing the current setup. Press [MEM] (3) [F1] [PEAK]. The 

display should be similar to Figure 2-6. 

A display of hyphens in place of a number in the power read-out portion of the display indicates 

that the power being sampled is below the measurement range of the system. Either the overall 

power of the pulse is too low, or the cursor has not been placed on a sufficiently high powered 

section of the pulse of interest. Another possibility could be no RF present. However, in this 

case, the PPM would not be triggering if Internal Triggering were being used and there was not 

enough RF at the detector input.) 

☛ NOTE: If the External Trigger mode is being used, the likelihood of obtaining a meaningful 

power reading at this point depends on the timing relationship between the RF pulse at the 

detector input and the external trigger pulse coming in through the rear panel input 

connection of the instrument. 

If the trigger pulse and the RF pulse are coincident in time, then the default Cursor Delay time 

of 1 µs will probably result in the Cursor being located somewhere on the pulse. This depends 

on the pulse width exceeding 1 µs. 

It is recommended that Internal Trigger is used before using the External Trigger mode so that 

pulse information such as pulse width can be obtained. This can save the effort of having to 

search for the pulse using the Cursor Delay function — Using the Graph Mode makes searching 

much easier. 

5. As already mentioned, the cursor (∆ symbol) next to the DLY indication on the display means 

that the spin knob is active and, if turned, will alter the value of the Cursor Delay (CSR DLY). 

To locate the highest power point on the pulse, it is best to start at the rising edge of the pulse 

and move the cursor gradually up in time until the power reading reaches its maximum point. 

This can be done as follows: 

a. Turn the spin knob counter clockwise until the Cursor Delay is zero (i.e. DLY = 0.000 ns on 

the display). 

b. Slowly rotate the spin knob clockwise while monitoring the power readout display. Note that 

the increments that the spin knob causes the DLY to step through will change faster as the 

knob is turned faster. Rotate the knob until the power readings increase. This indicates that 

the leading edge of the measured pulse being is being monitored. 

c. Continue increasing the Cursor Delay until the power readings go through a peak or stay at a 

high level. If the maximum power point is passed, turn the knob counterclockwise slowly, 

thus reducing the cursor delay until the maximum reading is once again reached. 

d. Press [FREQ] and enter either the desired RF operating frequency or the Cal Factor in dB as 

required. (This step is not necessary if the external frequency input mode is in use.) 

e. Enter any required dB Offset (see Section 2.6.2). 

f. The power will be displayed similar to Figure 2-6. The desired unit of power measurement 

can be selected by pressing [dB/mW]. 

6. If difficulties arise in locating the pulse to be measured, use the Graph Mode with Autoscale. 



Operation 

2.8.6 Peak Power Measurements Using the Graph Mode 

It is recommended that you read the basic information pertaining to the Graph Mode in Section 2.6.3 for 

a better understanding of this function. The initial Graph Mode (Cursor sub-mode) display looks 

something like that shown in Figure 2-7. Pulse profiles are shown graphically on the left side of the 

display while the right side displays the power and timing parameters pertinent to the pulse. 

Figure 2-7. Typical Initial Graph Mode Display 

To use the Graph Mode for peak power measurements, follow the instructions given next for accessing 

the Graph Mode: 

1. Connect the detector(s) to the detector connection(s) on the front panel, and allow the system to 

warm up for 30 minutes. Then conduct a Self Cal as described in Section 2.7. 

2. After ensuring that the pulse power of the RF source to be measured is not high enough to cause 

damage to the detectors (limit to less than +20 dBm), connect the channel A detector to the 

source. 

3. Select the Graph Mode of operation by pressing [GRAPH]. Press [AUTOSCALE] and the PPM 

will attempt to autoscale the pulse on the display. If there is no pulse present at the detector 

input or if the pulse power is below -10 dBm, then the PPM will not trigger (the New Data light 

will be out). 

While the PPM is Autoscaling, the display will indicate Autoscaling in Progress. When autoscaling is 

complete, the pulse will be centered in the graphics area of the display and the vertical cursor will be 

positioned at the center of the pulse profile. 

If the display does not indicate a pulse centered in the graphics area of the display with the vertical 

cursor positioned at the center of the pulse profile, then the autoscaling process was not successful. 

One possible reason that the PPM might not be able to autoscale is that the RF pulse might be too wide. 

The default setting of the PPM for the maximum pulse width that can be autoscaled is 75 µs. If desired, 

this maximum setting can be changed by pressing [MENU] (9) [F2]. 

2.8.7 Pulse, Cursor, and Marker Readouts 

On the 8500A, the Graph display mode has been enhanced to: 1) Simplify entry of timebase, triggering, 

and display scaling (CURSOR sub-mode), 2) Allow automatic readout of rise time, fall time, and pulse 

width (PULSE parameter sub-mode), and 3) Allow automatic readout of time differences between custom 

marker settings on the pulse (MARKER sub-mode). 

These three functions can be accessed by pressing [PULSE/CURSOR/MARKER] to cycle the display 

through the three sub-modes. 




2.8.8 Cursor Sub-Mode Functions 

The Cursor sub-mode is convenient for changing the timebase parameters of the display (the CurSoR 

DeLaY, the STaRT DeLaY, and the DeLaY WINDow), the scaling of the display (the REFerence PoWeR), 

and the trigger level if the PPM is in internal trigger mode. 

Figure 2-8. Typical Cursor Sub-Mode Digital Plot 

CSR PWR 

Indicates the power level at the location of the cursor. By pressing [MENU] (4) [F3], this can be 

indicated in either dBm or in Watts. This is a read-only function, and cannot be changed with the spin 

knob or numeric entry keypad. Placing the cursor here will prevent an accidental movement of the spin 

knob from changing a parameter. 

CSR DLY 

The Cursor Delay indication shows the amount of time after triggering has occurred that the Cursor will 

sample the power of the pulse. The time at which the trigger occurs is dependent on either the Trigger 

Level or, if External Triggering has been activated, on the triggering signal provided by the external 

source. The delta symbol next to CSR DLY means that the Cursor Delay is adjustable by using either the 

spin knob or the keypad. The cursor is placed by using either the up or down arrow key. 

STRT DLY 

This is the Start Delay of the graphics display area on the readout. It signifies the amount of time 

between the occurrence of the trigger and when readings begin at the left side of the graphics display. If 

the default value is still set, then the Start Delay would be set to 0.0000 ns and the left edge of the 

display will be coincident with the timing of the trigger. However, the Start Delay may be at whatever 

value was used the last time the Graph Mode was accessed. The cursor next to STRT DLY means that the 

spin knob or keypad can be used to adjust the Start Delay value. 

DLY WIND 

The Delay Window is the amount of time between the left and right sides of the graphics display area. 

The default value is 10.000 µs. When the Autoscale function is used, the PPM will adjust the Delay 

Window to display the pulse profile so that the trailing edge of the pulse can be seen. Autoscaling will 



Operation 

decrease the Delay Window in a 1, 2, 5 sequence as required until the trailing edge no longer disappears 

from view off of the right side of the graphics area. The cursor next to DLY WIND means that the spin 

knob or keypad can be used to adjust the Delay Window value. 

REF PWR 

The PPM’s Reference Power nomenclature refers to the manner in which the pulse profile is displayed. 

Referring to the graphics area of Figure 2-7, there are four horizontal tic (division) marks on the left 

vertical axis of the display. These tic marks correspond from top to bottom to the 100%, 90%, 50%, and 

10% power points on the pulse profile with respect to the Reference Power. The pulse profile is always 

displayed in linear units. The default Reference Power is 1 mW. However, once the Autoscale function 

has been used, the Reference Power is automatically adjusted to whatever the power level is at the middle 

of the pulse. Therefore, the Autoscale feature not only serves to center the pulse on the time (or 

horizontal) axis, it also optimizes the display positioning on the power (or vertical) axis by setting the 

highest power level as the 100% Reference point. 

The adjustable Reference Power level is provided to give the user flexibility in displaying the pulse, and 

measuring pulse timing parameters using the markers. This is important because it means that the PPM 

can be set up to accommodate the various types of test parameters that different users might need for 

their specific measurement requirements. 

NOTE: The reference power level is used as the 100% power level in the marker sub-mode, but is not 

used in the cursor or pulse parameter sub-modes. See the descriptions of marker sub-mode in 

Section 2.8.10 and cursor sub-mode in Section 2.8.8 for a more detailed explanation. 

There are two ways to set the Reference Power Level on the PPM. 

The first way is to move the cursor to the REF PWR (next to last) line of the displayed parameters (use 

either the up or down arrow key). Then, enter the desired Reference Power level and press the appropriate 

Units key (dBm for logarithmic units; mW, W, or kW for linear units). 

The second way is to move the cursor to the CSR DLY line and move the cursor to the point on the 

displayed pulse profile that is desired to be 100% reference. Next, move the cursor to the REF PWR line 

of the display. Then pressing any Units key will shift the pulse vertically on the screen, resulting in the 

selected point lining up with the 100% tic mark on the display. 

Reference Power cannot be changed with the spin knob. 

TRIGGER 

This display indicates the present triggering mode of the PPM. TRIG LEV = -10 dBm (A TRIG = 

-10 dBm in the 8502A) is the default setting. It means that the PPM will trigger when the leading edge of 

the RF pulse rises above -10 dBm at the (channel A) detector input. B TRIG = (8502A only) indicates 

that the PPM is triggering off the channel B detector. 

To change the Trigger Level, use either the up or down arrow key to move the cursor beside the TRIG 

LEV indication. The spin knob can then be used to alter the Trigger Level, or a desired number can be 

entered through the keypad and terminated with the dBm or mW key. 

EXTERNAL means that the PPM is triggering off the TTL trigger input on the back panel regardless of 

which channel is being displayed. 

Selecting External Trigger or changing the internal trigger channel is accessed through Menu-1. See 

Triggering in Section 2.6.2. 




2.8.9 Pulse Parameters Sub-Mode Functions 

Commonly used timing measurements required when analyzing pulsed RF/microwave signals are: 

• Pulse Width 

• Rise time 

• Fall time 

• Peak Power 

• Repetition Rate 

The pulse parameter readout allows the first four of these parameters to be measured directly by the PPM 

and displayed on the readout window. Auxiliary equipment may sometimes be required to measure 

repetition rate. 

While in the GRAPH Mode, the Pulse sub-mode routine is entered by pressing 

[PULSE/CURSOR/MARKER]. 

Figure 2-9. Typical Pulse Sub-Mode Digital Plot 

Pulse Rise Time, Width, and Fall Time 

The PPM displays the time between three pairs of start and stop power percentages. The default values 

for start and stop percentages are: 

Measurement Start % Stop % 

Rise time 10% rising edge 90% rising edge 

Fall time 90% falling edge 10% falling edge 

Pulse Width 50% rising edge 50% falling edge 

These parameters can be set or changed as follows: 

1. Press [PULSE/CURSOR/MARKER] to display the pulse parameters. 

2. Move the cursor (using either the up or down arrow key) to the Pulse Width line on the display. 

The current Start % setting will be displayed. 



Operation 

3. The last line of the display will show the prompt: 

Enter Start %. 

4. Enter the desired Start % setting through the numeric keypad. 

5. Press [UNITS]. 

6. The Enter Start % indication will change to: 

Enter End %. 

7. Enter the desired End % value and press [UNITS]. 

(Repeated pressing of any Units key will toggle the display between the Start and End values.) 

8. To change the start and stop percentages for rise and fall times, move the cursor to the 

appropriate line and repeat Steps 3 through 7. 

The relationship of 10% to 90% rise or fall time equals 2.198 time constants for a single pole 

circuit. Similarly, a 10% to 90% power rise or fall time equals 1.098 time constants. 

For some applications it is desirable to measure rise, fall, and width in terms of the voltage 

waveform instead of the power waveform. This can be done by simply modifying the appropriate 

start and stop percentages. The power waveform is proportional to the square of the voltage 

waveform. Therefore, to measure the voltage pulse parameters you would change the default 

percentages to the following: 

Measurement Start % Stop % 

Rise time 1% rising edge 81% rising edge 

Fall time 81% falling edge 1% falling edge 

Width 25% rising edge 25% falling edge 

The pulse rise time, fall time, and width are displayed with the appropriate time units. A display 

consisting of all dashes indicates that: 

a. the instrument failed to find the peak power point, or 

b. the instrument failed to find a start percentage point, or 

c. the instrument failed to find a stop percentage point. 

The method used to find pulse parameters is as follows. On each trace sweep, the instrument: 

A. finds the 100% pulse level. Starting from the trailing edge of the pulse, the instrument looks earlier 

and finds the largest flat section (±1 pixel on the screen) on the top of the pulse. This level is chosen 

as the 100% level. If no area is flat, (such as with gaussian shaped pulses) the maximum level found 

is used as the 100% level. This algorithm helps ignore the ringing and overshoot that sometimes 

accompanies rectangular pulses. Note that the display scaling (i.e., the REFerence PoWeR) is not 

reset and is independent of the 100% level found in this step. 

B. finds the rise time, fall time and width of the pulse. In order to improve the accuracy of timing 

measurements. You should set the delay window so that the pulse fills at least 20% of the screen. 




2.8.10 Marker Sub-Mode Functions 

The Marker sub-mode is another completely independent way to read the time difference between user 

defined points on the pulse waveform. It may, at first, seem redundant with the Pulse parameter mode. 

The Marker sub-mode, however, treats the 100% power point differently, and reads the differences 

between four user-defined points on the waveform. It is intended for use in specialized applications (such 

as measuring the linearity of the leading edge skirt of a navigation pulse) where the user is interested in 

something other than standard rise, fall, and width measurements. This Marker sub-mode is also most 

similar to the Marker Mode offered in the original 8500 Peak Power Meter. 

The Marker sub-mode uses the user-set REFerence PoWeR as the 100% power point of the pulse. This 

allows the user to set the 100% point at other than the flat spot at the top of the pulse. For instance, the 

100% point can be set at the top of the pulse overshoot. The 100% point can also be set 10 dB lower than 

the top of the pulse to scale all the user-set marker percentages by 1/10. This is particularly useful to set 

marker percentages to resolutions better than 0.1% of the peak power. 

The default settings for marker sub-mode are set for the measurement of linearity on the leading edge of 

a navigation pulse. In this particular measurement, the time between the 5%, 13.3%, 21.7%, and 30% 

points on the voltage waveform are compared. Equal times indicate a linear voltage waveform between 

the 5% and 30% point on the waveform. Because markers are entered in terms of % power, the 

corresponding power percentages would be 0.25%, 1.78%, 4.69%, and 9.00%. Because markers can only 

be entered to 0.1% resolution, the actual marker values are set 10 times greater or 2.5%, 17.8%, 46.9% 

and 90.0%. Then, to get the maximum resolution from the markers the REFerence PoWeR is set to 

exactly 10 dB less than the peak power of the pulse, effectively scaling all marker values by 1/10. (This 

action must be done manually.) 

Figure 2-10. Typical Marker Sub-Mode Digital Plot 

To change a marker percentage setting: 

1. In GRAPH mode, press [PULSE/CURSOR/MARKER] until you see a display on the right side 

of the screen similar to: 

∆CSR PWR = +0.91 dBm 

MKR 2 - 1 = 4.9000 ns 

MKR 3 - 2 = 5.4000 ns 

MKR 4 - 3 = 10.5000 ns 



Operation 

2. Move the cursor (using the up or down arrow keys) to the MKR 2-1= line on the display. The 

current marker percentage setting for marker 1 will be displayed. 

3. Enter the desired Marker 1 percentage through the numeric keypad, using any Units key to 

terminate the entry. 

4. Repeat steps 2 and 3 at the MKR 3-2 = line to change the Marker 2 percentage, and the MKR 

4-3 = line to change the Marker 3 percentage. To change the Marker 4 percentage, move the 

cursor to the blank line just below the MKR 4-3 = line. 




2.9 Digital Plotting of Graphic Data 

2.9.1 Plotters Supported 

The PPM is configured to provide direct output of Graph Mode information for hardcopy recording on a 

digital plotter. This is done without the necessity of using a computer or GPIB controller. The following 

plotters (and any other 100% compatible plotters) are supported: 

Hewlett-Packard Model 7440A 



All of the above plotters must be configured with the option for GPIB usage. 

2.9.2 Procedure for Making Plots 

The procedure for making plots with the PPM is quite simple. Plots can be made when in the Graph 

Mode and Marker sub-mode, and the plots will be essentially duplications of the information shown on 

the PPM display at the time the plot function is activated. 

Two different plotting speeds can be selected by the PPM. These are: a Fast Plot for use with normal 

plotting paper, and a Slow Plot for making plots using transparent paper (film). 

To make a (fast) paper plot, press [MENU] (2) [F3] [F1] 

To make a (slow) transparency plot, press [MENU] (2) [F3] [F2]. 

When the PPM has drawn a complete pulse profile on its display, it is ready to act as a GPIB controller. 

If the PPM is part of a GPIB system, it is up to the user to be sure that no front panel plot function is 

initiated to ensure correct operation of the system. 

The following steps are required to generate an X-Y hardcopy plot: 

1. Connect a GPIB cable from the PPM’s rear panel GPIB connection to the plotter’s GPIB input 

connection. 

2. Choose a GPIB address for the plotter, and set its address switches according to the instructions 

in its operating manual. (Address 6 is recommended; see Step 3.) 

3. Select the plotter address for the PPM by pressing [MENU] (6) [F2] [nn] [UNITS]. 

Where nn is the plotter address. The default address to which the PPM sends data is 6. If the 

plotter address is changed from the default value of 6, it will remain at the new value until 

another value is entered. That is, it is not reset at power-on or any other time until intentionally 

changed again. 

4. Check that the plotter pens are installed and operating properly. Following the manufacturer’s 

instructions, insert paper into the plotter and prepare it to plot. 

5. If it is required or desired, enter a Code number or Part number to be printed on the plot. If no 

Code and Part numbers are selected, numbers previously entered will be plotted. The default 

numbers are blank. 

a. Enter the Code number as follows: 

[MENU] (5) [F1] [n] [UNITS] 

(n is a number up to 12 digits.) 



Operation 

b. Enter the Part number as follows: 

[MENU] (5) [F2] [n] [UNITS] 

(n is a number up to 12 digits). 

6. The date and time are always plotted. The date and time are obtained from the internal, real-time 

clock of the PPM which is kept alive by a battery when the instrument is turned off. If it is 

desired to check and/or change the date and time before plotting, press [MENU] (5) [F3] [F3] (if 

clock is correct) 

or, to change the clock, [MENU] (5) [F3] [F1] [mmddyy] [UNITS] [hhmmss] [UNITS] [F3] 

where mmddyy = month, day, year; and hhmmss = hours, minutes, seconds 

7. Enter the Graph Mode. The Delay Difference Timing will be plotted if it has been activated on 

the readout. See Figures 2-8, 2-10, and 2-9 for examples of the types of plots available from the 

PPM. 

8. Before the PPM can make a plot, it must first complete one sweep of the pulse profile. Assuming 

the profile is completed, press [MENU] (2) [F3] [F1] for a paper plot or [MENU] (2) [F3] [F2] 

for a transparency plot. 

9. If there is any GPIB bus error, an alarm will sound. This indicates that when the PPM checked 

the IEEE Bus, it was unable to activate the plotter. Some possible causes for this might be an 

incorrect address setting, the plotter not set up correctly, or the plotter is turned off or out of 

paper. If this situation occurs, press [F2] to return the PPM to its previous mode of operation. 

This feature allows PPM operation to continue despite bus hang-ups. 

The GPIB bus error alarm consists of 2 audible beeps and a display of GPIB BUS ERROR 

A single beep indicates that there are no problems, and that plotting will begin as soon as the trace has 

been drawn on the display screen. 

Once the plot has started, control of the PPM can be regained before the plot has finished. This gives the 

ability to proceed with further testing without having to wait for the plotter to complete its task. 

If it is necessary to Abort the plot for some reason, press [MENU] (6) [F1]. The plot will be terminated 

as soon as possible. 




2.10 Dual Channel Measurements 

Dual channel measurements are available only when using the Model 8502A power meter. The dual 

channel capability of the Model 8502A provides two very useful functions. These are: 

• Display of power measured by two channels simultaneously. 

• Display of the power ratio between two channels. 

Applications for these two functions are many and varied. Dual channel measurements allow two points 

in a system to be measured with one power meter. The PPM can simultaneously measure both channels in 

either the CW or Peak Power Modes. 

The Ratio function allows relative measurements to be made in either CW or Peak. It is also possible to 

ratio Peak to CW or CW to Peak. These functions are useful for gain and loss measurements under CW 

or Peak conditions (or a combination of the two). 

2.10.1 CW, CW Measurements 

The following procedure is used for making dual channel CW measurements: 

1. After power-on, press [CW] to access the CW Mode. Press [MEM] (3) [F1] for the PPM to use 

its default values, if desired. Wait approximately 30 minutes for the PPM to warm up. 

2. Self-Calibrate both channels. Press [MENU] (1) [F3] [F1]. 

3. Follow the instructions displayed by the PPM to connect the appropriate detector to the 

Calibrator when prompted. 

4. Connect the detectors to the device(s) or system to be tested. 

5. The PPM will now be displaying the CW power for channel A. To display the CW power for 

both channels, press [B]. 

6. Select the frequency of operation or cal factor as necessary for detector response correction by 

pressing [FREQ]. 

7. Enter any required display offsets. 

8. To return to single channel operation, use the Detector Select A and B keys as required. 

2.10.2 Peak, Peak Measurements: Method 1 

1. Follow the procedure given in Section 2.10.1, except press [PEAK] in Step 1 instead of CW. 

2. If the PPM is triggering, it will display the peak power in both channels. The following default 

settings are in effect if the PPM has been initialized. 

a. Internal Trigger from channel A set at -10 dBm (i.e. pulse at channel A causes trigger if 

greater than -10 dBm) 

b. Frequency = 1.00 GHz 

c. Chan A Cursor Delay = 1.0000 µs 

d. Chan B Cursor Delay = 1.0000 µs 

e. Spin knob active on channel A Cursor Delay as indicated by ∆ next to CSR DLY 

3. If the PPM’s New Data and Ready lights are flashing, a trigger is occurring and measuring 

should be possible. Try adjusting the channel A Cursor Delay by turning the spin knob until the 

CSR DLY reads 0.0000 ns. The Delay can then be increased slowly until the reading is being 

taken on the desired part of the pulse. 



Operation 

4. To change the Cursor Delay for channel B, press the up or down arrow key. The spin knob can 

then be used to alter the channel B Cursor Delay. To lock out the spin knob and keyboard, press 

any UNITS key. To reactivate the spin knob and keyboard, press the up or down arrow key. 

5. If there are any difficulties due to timing factors, it is recommended that External Triggering be 

used. The trigger signal should occur slightly before the RF pulses to be measured. The Cursor 

Delays can then be used to place the Cursors on the pulses to allow readings to be taken. 

2.10.3 Peak, Peak Measurements: Method 2 

This method utilizes the Graph Mode to facilitate placing Cursors on the pulses of interest. Signal timing 

should be considered first of all. For purposes of discussion, assume the timing of the signals to be 

measured are similar to those shown in Figure 2-11. 

As can be seen in Figure 2-11, the Measurement Port 1 pulse occurs before the Measurement Port 2 

pulse. If Measurement Port 2 were used to generate an Internal Trigger, it would be impossible to set the 

Cursor on the leading edge of the displayed Measurement Port 1 pulse because the minimum Cursor 

Delay of 0 ns would be the trigger point (leading edge of the Measurement Port 2 pulse). 

Figure 2-11. Typical Signal Timing 

Therefore, this situation would require that either Measurement Port 1 be used to generate an Internal 

Trigger, or that an External Trigger be used. Doing this would ensure that readings could be taken at any 

desired points on the pulses being measured. 

In cases where the pulses at each detector input are essentially occurring at the same time, this problem 

could be ignored. However, it is generally the case that using the External Trigger results in more 

satisfactory performance. 

The preceding information is provided mainly to emphasize the importance of knowing the timing 

relationships of the signals to be measured. If there is any doubt or confusion, the rear panel Monitor 

Output of the PPM can be connected to an oscilloscope to quickly ascertain the timing relationships. 

Assuming an autoscalable pulse greater than the current trigger level is to be measured by channel A for 

this example, the procedure for Dual Channel operation in the Peak Mode via the Graph Mode would be: 




1. Connect the channel A detector to the RF source (port) that is believed to be generating a pulse 

before the second source (port) to be measured (i.e. Measurement Port 1). If the pulses of the 

two sources are coincident, use either port. 

2. Connect the channel B detector to the second source (port). 

3. Select the Graph Mode in channel A, and press [GRAPH] to Autoscale. 

4. After the pulse has been successfully Autoscaled, set the Cursor to the desired measurement 

point. 

5. Make a note of the Window and Cursor Delays. (The Start Delay will be 0.0000 ns after 

Autoscaling.) 

6. Press Detector Select [B] to switch to the channel B Graph Mode. 

7. Set the Window and Cursor Delays to the same values as were noted in Step 5. If the pulse is not 

visible on the readout, gradually increase the Start Delay until the entire pulse is on the screen. 

8. Set the Cursor Delay to the point on the pulse where it is desired to take a measurement. Channel 

A and B Cursors should now be placed wherever dual channel readings are to be taken. This can 

be verified by pressing Detector Select [A] or [B] as necessary to check that the Cursors are 

properly positioned. 

9. Select the Peak Mode of operation by pressing [PEAK]. 

10. Select Dual Channel operation by pressing Detector Select A. Make sure that the LEDs in the 

center of the Detector Select A and B keys are lit. This signifies that the PPM is in the Dual 

Channel Mode. The display should be similar to the following: 

A: +0.65 dBm, 30.600 ns 

B: -4.65 dBm, 39.700 ns 

FREQ = 1.00 GHz, PEAK 

2.10.4 Peak, CW Measurements 

If it is desired to measure Peak power on one channel and CW on the other channel, the procedure is the 

same as when measuring Peak Power on both channels with some minor differences. These differences 

are: 

1. The channel used to make the Peak power measurement determines the triggering of the PPM. 

For low amplitude signals (below -20 dBm in the Peak Mode), use external triggering. 

2. It is not necessary to use the Graph Mode or any Delay settings on the channel that will be 

measuring CW as the power will be continuous, and it makes no difference at what time the CW 

is sampled. 

3. Even though one channel is displaying CW power, the PPM operates as though both channels 

were in the Peak Mode. CW averaging has no effect on the reading. The rate at which the RF is 

sampled and averaged is determined by the characteristics of the Peak power channel. 



Operation 

2.10.5 Power Ratio Measurements 

To make ratio measurements, the power measured by both channels must be within the specified power 

measurement range of the PPM system. When operating in CW, this power range is -40 to +20 dBm. In 

the Peak Mode, this power range is -20 to +20 dBm. Power readings taken in the Ratio Mode outside of 

these ranges will result in an error display. 

The Ratio Mode only provides the ratio of A/B, not vice versa. The PPM can ratio two CW signals, two 

Peak signals, or a combination of both. The following procedures show how to perform each of these 

ratio’ing operations. 

Ratio’ing Two CW Signals 

This is the easiest ratio function of the PPM. Proceed as follows: 

1. Allow the PPM to warm up for at least 30 minutes. Then Self-Calibrate both channels. From 

power-on, press [CW] [MENU] (1) [F3] [F1]. 

Follow the displayed prompts to complete the Self-Cal. After Self-Cal has completed, the PPM 

will be measuring CW power in channel A. 

2. Select the Ratio Display Mode by pressing [MENU] (7) [F2]. 

3. The default mode for power ratio measurements is for Peak power on both channels. To set both 

channels for CW operation, press [A] [F2] [B] [F2]. 

The PPM will now be reading the ratio of A/B. Normally this is expressed in dB, however, it can also be 

expressed as a linear reading (such as 19654 EXP=-4) by pressing [dB/mW]. The display indicates that 

two CW signals are being ratio’ed by displaying CW/CW in the lower right hand corner of the display. 

Remember that the frequency of operation or Cal Factor must be entered using the FREQ key, and any 

desired Offsets should also be included. These two functions are described in Sections 2.8.3 and 2.8.4. 

Ratio’ing Two Peak Signals 

The point in time at which readings of Peak power are taken in both channels for ratio’ing purposes is 

determined by the setting of the Cursor Delay. Although it is most desirable that both pulses being 

monitored occur at exactly the same time, in practice this would be a very rare event. Therefore, the 

signals to be measured must be carefully evaluated to ensure that accurate readings are taken. 

The Cursor Delay must be set so that samples are being taken on both the channel A and B pulses. See 

Figures 2-12 and 2-13 for an examples of good and bad Cursor Delay settings in this situation. 

The following are guidelines that can be used when ratio’ing two Peak signals: 

1. Make a single channel Peak measurement using the Graph Mode (Autoscaling is recommended). 

2. Set the Cursor Delay so that the power reading (CSR PWR) is being taken close to the center of 

the pulse (see Figure 2-12). 

Figure 2-12. Typical Peak Power Ratio Display 




3. Verify that the Cursor Delay setting is adequate for both channels by switching to the other 

channel. Use the same Start, Window, and Cursor Delays as in the first channel. If the pulses 

occurred at the same time, the Cursor would be close to the center of the pulse sampled by the 

other channel (see Figure 2-13). 

GOOD 

BAD 

Figure 2-13. Typical Good & Bad Cursor Delay Settings 

4. Switch channels, checking to be sure that the Cursor is not placed close to the edge of either of 

the pulses being sampled. 

5. Once the Cursor has been satisfactorily set, to activate the Ratio Display Mode press [MENU] 

(7) [F2]. 

The default setting for the type of signal being used by both channels is Peak. This is verified by PK/PK 

being displayed in the lower right hand corner of the readout. If this is not the case, select Peak operation 

by pressing [A] [F1] [B] [F1]. 

The PPM should now be displaying the ratio of the two pulses (similar to Figure 2-12). Be sure to use 

the FREQ key and Offset function if necessary. 

Ratio’ing Peak to CW Signals 

This function is very useful in many applications such as traveling wave tube (TWT) testing that require 

the measurement of gain under pulsed conditions. This could be a problem when the TWT has a CW 

input and a pulsed output. The PPM easily performs this type of measurement using the following 

procedure: 

1. Make a single channel Peak measurement at the port of the device under test that has the pulsed 

signal. 

2. Set the Cursor at the desired point on the displayed pulse profile. Using the Graph Mode is the 

simplest way to do this. 

3. Select the Ratio Mode by pressing [MENU] (7) [F2]. 

4. Set which channel will be CW by pressing [B] [F2] (if channel B is to be CW) or [A] [F2], (if 

channel A is to be CW). 

5. Set which channel is to be Peak by following the same procedure as above, only press [F1] 

instead of [F2]. 

The lower right hand corner of the readout will indicate which channel is CW and which is 

PEAK. Whichever indication is farthest to the right side will be channel B. 



Operation 

2.11 High Power Measurements 

One of the most important things to remember when using the PPM is that it employs balanced, zero 

bias, Schottky diode detectors as power detectors. Due to this highly sensitive, highly accurate 

configuration, the maximum power that the detectors can handle before burning out is +23 dBm 

(200 mW). This limitation is regardless of duty cycle. 

2.11.1 Power Warning - Max/Min Power Limits 

The PPM has a built-in warning system to advise you of mild overloads to the detectors. Large overloads 

which are usually the result of a failure in the device under test or leaving an attenuator out of the test 

setup, cannot be prevented because of the speed at which these failures happen. However, you will be 

advised by a prompt when the power level exceeds the preset power warning level. 

The default value for the MAX Power warning point is +20.5 dBm. You can set this to anywhere between 

-10 and +21 dBm. 

The PPM also has a lower level limit (MIN). This is mainly used to avoid displaying power readings 

outside the lower power range of the instrument. When the power level being measured by the PPM is 

below the lower level limit, the readout will display a series of dashes to indicate that the power being 

measured is too low for the PPM to take an accurate measurement. 

The default value for the MIN Power warning point is -45.0 dBm. You can set this anywhere between -15 

and -50 dBm. To change the MAX and MIN power limits, press [MENU] (7) [F1] [mm.mm] [dBm] 

[nn.nn] [dBm], where mm.mm is the maximum power limit, and nn.nn is the minimum power limit. 

2.12 High Power Measurement Procedures 

The procedure for making absolute CW or Peak power measurements under high power conditions is as 

follows: 

1. Approximate the Peak power of the signal to be measured. 

2. After 30 minutes warm-up, Self-Cal the PPM detectors. 

3. Choose an appropriate attenuator or coupler to be used in the test setup to reduce the power 

being measured to a safe level for the detectors. The power at the detector input must be less 

than +20 dBm. 

4. When making this approximation, be sure to use worst case power levels. If in doubt, a 10 dB 

attenuator can be used directly on the detector input in addition to the selected high power 

coupler or attenuator. 

5. Ensure that the RF power of the source to be measured is turned OFF. 

6. Connect the high power coupler to the RF source to be measured as shown in Figure 2-14. If a 

high power attenuator is used, connect as shown in Figure 2-15. 

7. Connect the PPM detector with its attenuator to the coupled output of the high power coupler 

(Figure 2-14), or to the output of the high power attenuator (Figure 2-15). 




Figure 2-14. Detector to a High-Power Coupler Setup 

Figure 2-15. Detector to High Power Attenuator Setup 

8. Auto-Zero the PPM by pressing [MENU] (1) [F3] [F2] [UNITS]. 

If a dual channel 8502A is being used, follow the prompts given on the display. Select any Units 

key or CLEAR as necessary to Zero the desired channel(s). 

9. Turn on the RF power of the source under test. 

10. If measuring a pulsed signal, it is important that the Cursor be placed on the pulse. This can be 

done by using the PPM’s Autoscale feature which is activated in the Graph Mode by pressing 

[AUTOSCALE]. If this method is not possible, try using the Internal Trigger with the level set at 

-20 dBm. Then set the Cursor at 0.0000 ns and increase the Cursor Delay gradually until the 

CRS PWR is at its maximum. 



Operation 

If the New Data light on the front panel of the PPM does not flash, then the instrument is not 

triggering. If the trigger level is at -20 dBm and no trigger occurs, there might not be enough 

power at the detector input to be able to measure. If this is the case, recheck the calculations that 

were made to decide what attenuation levels were required to prevent detector burnout. If 

necessary, reduce the attenuation at the detector input by 10 dB to increase the power so that the 

PPM will trigger. 

☛ NOTE: If a TTL Trigger signal is available from the source being measured, then using the 

External Trigger Mode is advisable. If an oscilloscope is available, the PPM’s rear panel 

MONITOR OUTPUT(s) can be used to determine the proper timing settings for the 

instrument. 

11. Once the PPM is reading power as desired, press [FREQ] and enter the frequency of operation 

(or Cal Factor). 

12. To obtain the absolute power output of the RF source being measured, use the PPM’s Offset 

feature to offset the displayed values by the combined attenuation values of the coupler and/or 

attenuators being used in series with the detectors. Most couplers and attenuators have 

attenuation versus frequency response curves supplied that can be used for exact entry of the 

required offset. To enter the Offset, press [MENU] (3) [F1] [nn.nn] [dBm]. 

Where nn.nn is the Offset desired. For channel B offset on the 8502A, use F2 instead of F1. When the 

Offset feature is in use, this will be shown on the display by an asterisk (*) next to the FREQ or CF 

indication. 

2.12.1 High Power Relative Measurements (8502A only) 

The procedure for making a gain or loss measurement is the same as for absolute power, but requires 

activating the Ratio Display function of the 8502A. The Offset feature compensates for external devices 

before entering the Ratio Mode (see Power Ratio Measurement Procedures in Section 2.12 for more 

information on ratio’ing). 




2.13 Special Capabilities of the PPM 

2.13.1 Reference Delay 

To facilitate making timing measurements relative to some event other than the trigger (such as the 

falling edge of a pulse), it is possible to shift the PPM time coordinates by using Reference Delay. The 

PPM subtracts the Reference Delay from the Cursor Delay and Start Delay, in effect shifting the zero 

time reference from the trigger time to a time after the trigger by the amount of the Reference Delay. To 

set the Reference Delay press [MENU] (4) [F1] (for Ch A or [F2] for Ch B) [nn.nn] [UNITS]. 

2.13.2 Single Pulse Measurements 

Measurement of a single pulse can be done with the PPM by operating in the Peak Mode. (The Graph 

Mode cannot be used for single pulse measuring.) 

Two methods are available for making single pulse power measurements. These are discussed in the next 

two sub-sections. 

2.13.3 Single Pulse Measurement Using Internal Trigger 

To make a single pulse measurement using the Internal Trigger, it must first be decided how long after 

the trigger has occurred that the measurement should be taken. For example, in the single pulse shown in 

Figure 2-16, the PPM trigger level is set to -10 dBm. If the Cursor Delay were set to 0.0000 ns, then the 

power measurement would be taken at the trigger point. In this case, this is not on the top of the pulse 

being measured. 

To measure power at the top of the pulse as required in most applications, the Cursor Delay needs to be 

set at around 5 µs. Therefore, to accurately make Peak power measurements using the Internal Trigger 

mode of operation, you must have some idea of the pulse width boundaries to be tested. 

In cases where the rise time of the pulse is known to be repeatable and the pulse width is known never to 

be below, say, 8 µs, you could set the Cursor Delay to 5 µs. This decision would allow measurement of 

all pulse widths greater than 5 µs without the necessity of altering the Cursor Delay. 

Figure 2-16. Typical Pulse with -10 dBm Trigger Level 



Operation 

Single pulse measurements cannot be made with the same accuracy as repeating pulse trains. This is 

primarily due to the fact that there is no way to eliminate noise that might be present in the test setup. 

For repetitive pulse trains, averaging can be used to eliminate errors due to noise. 

The procedure for making a single pulse measurement is as follows: 

1. Allow the PPM to warm up for 30 minutes, then conduct a Self-Cal. 

2. Select the Peak Mode of operation. If there is no pulse at the detector input there will be no 

trigger. If this is the case, the display will either be blank or frozen with the last data that was 

taken. The Ready light should be lit, the New Data light will be dark. 

3. Set the Trigger Mode to Internal, and then set the trigger level as desired. 

4. Set the Cursor Delay to the desired time following the trigger that the measurement is to be 

taken. Press [GRAPH]. Move the cursor to CSR DLY. Enter the desired delay (for this example, 

use 5 µs) through the keypad, and terminate with the ms, µs, or ns key. Then press [PEAK]. 

5. Set the Peak Pulse Averaging number to 1. 

6. Connect the detector to the RF source to be measured. 

7. When a pulse of sufficient amplitude to cause a trigger enters the detector input, the PPM (in this 

case) will take a reading 5 µs later. The Peak power being measured at the time of the Cursor 

Delay will then be frozen on the display until the next pulse or trigger occurs. 

2.13.4 Single Pulse Measurement With an External Trigger 

Making a single pulse measurement using an External Trigger is done with the same limitations as with 

the Internal Trigger. However, it is possible to control exactly when the power reading is taken by 

supplying a TTL trigger to the PPM’s rear panel trigger input at the appropriate time. 

The PPM is set to External Trigger by pressing [MENU] (1) [F2]. 

The trigger signal must arrive coincident with or before the RF pulse to be measured when measuring 

with the External Trigger. If the power reading needs to be taken exactly at the time that the trigger 

occurs, then the Cursor Delay is set to 0.0000 ns. If the pulse to be measured arrives after the trigger, 

then set the Cursor Delay so that the power reading will be taken at the desired point on the pulse. 




2.14 Swept Peak Power Measurements 

The frequency response and power level characteristics of pulsed signals can be measured under swept 

frequency conditions by combining the capabilities of the Giga-tronics PPM with those of the 

Giga-tronics Model 8003 Scalar Network Analyzer. 

The Analyzer’s normalization memory can be used to subtract out residual test setup responses, thus 

allowing direct readout of the frequency response of the device under test. There are a variety of 

applications where this ability can be very useful such as: 

• Pulsed TWT testing 

• Microwave frequency performance of pulsed radar systems 

• Return Loss 

• VSWR Measurements under Pulsed Conditions 

• and others. 

Figure 2-17 illustrates a typical setup for measuring swept peak power. 

Figure 2-17. Typical Pulsed Swept Measurement System 

If a Giga-tronics Scalar Analyzer system is not available, a conventional oscilloscope can be used by first 

displaying the PPM’s output, and then marking the system tracking errors on the CRT in grease pencil for 

visual correction. 

The PPM is normally used in the Peak Mode for this type of testing. Most PPM settings would be the 

same as when measuring a single frequency pulsed signal. In order to use the Swept/Pulse system with 

any degree of accuracy, the pulse repetition rate must be considerably faster than the speed at which the 

RF sweep takes place. This is determined mostly by the setting of the sweep generator’s sweep speed. 

The PPM is capable of reading better than 100 pps, and the output level will be at 100 mV/dB. Swept 

measurements can also be made simultaneously from channels A and B of the 8502A, but the PPM’s 

reading rate will be somewhat slower. 

It is very convenient to use the sweep generator’s Frequency Reference signal to continually inform the 

PPM as to what the RF frequency is at any given time. (Frequency Reference is synonymous with 

V/GHz, VpropF, etc.) Using this feature ensures that, as the sweep generator changes frequency, the PPM 



Operation 

knows to alter its frequency correction accordingly. The PPM then uses the proper frequency correction 

accordingly. The PPM then uses the proper frequency correction for the detector(s) at each discrete 

frequency point without necessitating any operator input or any calculations (see Section 2.8.2 more 

information on the interfacing of external frequency signals.) 

To make swept frequency measurements under pulsed conditions, equipment should be set up similar to 

Figure 2-17. The measurement routine is initiated by pressing [MENU] (10) [F1]. 

During the time that the fast analog output mode is active, the display window will indicate: 

FAST ANALOG OUTPUT 

MEASUREMENT MODE 

Press [MENU] to exit 




2.15 Self-Testing the 8500A 

Prior to performing a self-test during a testing routine (at some point after the instrument has been turned 

on), the detector must either be connected to the Calibrator Output on the front panel, to a 50-ohm 

termination, or to a signal source which has the RF power turned OFF. 

The Self-Testing feature of the PPM is provided as a quick health check of the instrument. The PPM 

performs a Self Test each time it is powered on. To initiate the Self-Test function at other times: 

First remove all RF power from the detector. Then press [MENU] (11) [F2]. While the Self-Test is in 

progress, the following will be displayed: 

Performing Self-Test 

CLOCK/CALENDER INDICATES 

(day) (date) (time) (year) 

System version # = n.nn 

At the successful completion of the Self-Test, the PPM will display Self Test Completed: Passed. A beep 

will then sound, and the PPM will return to its previous display mode. 

If some type of failure is detected by the PPM’s microprocessor during the Self-Test, the display will 

indicate: 

SELF TEST FAILED! - PRESS CLEAR 

ERROR NUMBER(S): 11, 8, etc. 

Table 2-1 gives a listing of the error numbers and their associated meanings. 

Table 2-1. Self-Test Error Flags 

Error 

Cause 

01 -5.2 V Supply 

02 Memory Bad 

03 Excessive A Channel Offset 

04 A Channel Gain Error 

05 Excessive B Channel Offset 

06 B Channel Gain Error 

07 A Channel Analog Output DAC 

08 B Channel Analog Output DAC 

09 Delay 8555s (ICs) 

10 Delay Time Error 

11 Calibrator Bridge Voltage Error 

Press [CLEAR] to bring back the display of the last setup before Self-Test. However a failed Self-Test 

indicates a problem of some kind, and it is recommended that the PPM not be used for measuring until it 

is checked according to the procedures given in the Troubleshooting instructions in Chapter 6. 



Operation 

2.16 Frequency Display Disable/Enable 

If there is some reason (such as classified testing) why it might be desired not to have the frequency of 

operation displayed while measurements are being taken, this can be done by using the F3 key of MENU 

(7) as a toggle for this function. 

Pressing [MENU] (7) [F3] the first time will replace the frequency numbers at the bottom of the display 

window with asterisks. 

When you desire to return to the normal frequency display mode, press [MENU] (7) [F3] again and the 

numbers indicating the frequency will return. 

2.17 Non-Volatile Memory 

The PPM Non-Volatile Memory is intended to Store front panel settings for later Recall. This is 

particularly useful when complicated setups are in use. Usage of this feature can save many menu 

selections that might otherwise have to be entered every time the instrument is used. 

The PPM stores all front panel information pertaining to the present setup in a memory location called 

Current Setup. When the PPM is turned off, Stored setups and the Current setup in memory are kept alive 

by a Lithium battery (exceptions are detailed in Section 1.3). The battery will ensure that the contents of 

the memory will be preserved for about six months. 

When the PPM has been turned on and Self-Test either completed or bypassed, the opportunity will be 

presented to select Last Setup at Turn-Off. If it is desired to use the PPM in the same manner as when it 

was last used, this feature of the Non-Volatile Memory is very convenient. Other features of the 

Non-Volatile Memory will be discussed next. 

2.17.1 Memory Features 

To access the Memory features of the PPM, press [MEM]. There are three levels of menus accessible by 

sequentially pressing the MEM key. The menus accessed through the Memory key are detailed in 

Appendix B. If you mistakenly access the Memory menu, press [CLEAR] to return to the Data Display 

Mode. 

Store Setup 

The PPM has 10 Non-Volatile Memories for storing front panel setups. These are numbered from 1 

through 10. To store the present PPM front panel setup in one of these 10 memories, press [MEM] (1) 

[F2] [nn] [UNITS]. 

Where nn is the number of the memory where the setup is to be stored (between 1 and 10). If no number 

were entered, the operation would be aborted when any Units key was pressed and the PPM would return 

to data display. 

Recall Setup 

To Recall a previously stored setup, press [MEM] (1) [F1] [nn] [UNITS]. 

Where nn is the number of the memory to be recalled (from 1 to 10). If no number is pressed, the 

operation is aborted when any Units key is pressed and the PPM will return to data display. 

Get Power-On Setup 

To retrieve from memory the front panel setup that was operative the last time the instrument was used 

before power-off or the rear panel RESET button was used, press [MEM] (1) [F3] 




☛ NOTE: This selection will erase the Current selection. It is advisable to store the setup in 

a numbered memory before executing the command. 

Display Setups 

When one of the Display Setup features of the PPM is activated, the panel settings of the selected setup 

are shown on the display. This is useful if it is desired to determine the exact parameters that were used 

for a particular setup, and allows checking whether or not the various settings are correct before making 

any measurements. 

1. To Display the contents of the Current setup, press [MEM] (2) [F1]. The PPM will then display 

the current instrument status readout in a screen by screen display mode. To scroll to the next 

screen display, press the F1 key for More. To exit and return to the Data Display Mode, press F3. 

2. To Display the contents of the Power-On setup, press [MEM] (2) [F2]. The PPM will then 

display the Power-On instrument status readout screen by screen. To scroll to the next screen, 

press [F1] for More. To exit and return to data display, press [F3]. 

3. To Display a numbered memory setup, press [MEM] (2) [F3] [nn] [UNITS], where nn is the 

number of the memory (between 1 and 10) that is to be displayed. If no number is entered, the 

operation is aborted when any Units key is pressed and the PPM returns to data display. 

The PPM will display the instrument status readout of the Memory screen by screen. To scroll to the next 

screen display, press [F1] for More. To exit and return to data display, press [F3]. 

Initializing Setups 

This feature of the PPM allows the initializing of the current setup, a numbered memory setup, or all but 

the current setup (see Section 1.3). Initializing resets the selected setup’s parameters to the factory default 

settings. Certain parameters are not initialized. The Initializing function can be useful if, for some reason, 

you get lost or have difficulty interpreting readings due to the complexity of a particular setup. 

Initializing also allows parameter settings to be made from a known status. 

1. To Initialize the Current setup, press [MEM] (3) [F1]. 

☛ NOTE: This selection will erase the Current setup. It is advisable to store the setup in a 

numbered memory before executing the command. 

2. To Initialize all memory setups except for the Current setup, press [MEM] (3) [F2]. It is a good 

idea to Display the contents of the numbered memory setups before executing this command to 

see if it is desired to retain any of the setups in question. 

3. To initialize a numbered Memory setup, press [MEM] (3) [F3] [nn] [UNITS], where nn is the 

number of the memory (between 1 and 10) to be initialized. If no number is entered, the 

operation is aborted when any Units key is pressed and the routine will return to data display. 



Operation 

2.18 1018B Peak Power Meter Emulation 

2.18.1 General 

The Giga-tronics Model 1018, 1018A, and 1018B series of peak power meters were the predecessors to 

the Model 8501A/8502A meters. This 1018 series was first produced in 1969, and has had several design 

up-grades. In 1978 Pacific Measurements, Inc. (now known as the Giga-tronics Power Measurements 

Division) added limited IEEE Bus capability to the 1018, but no provision was available for controlling 

front panel states. Only the cursor delay, trigger or reset, and the taking of data was remotely controllable. 

The purpose of the 1018B emulation mode is to provide a means for current users of the 1018B to 

quickly adapt to using the 8501A/8502A meters in automatic systems. While perfect emulation is not 

possible, the PPM can mimic certain operations of the 1018B. This emulation relates only to GPIB (IEEE 

Bus) operations. That is, the ability to reset, trigger, alter the cursor delay, and take a power reading over 

the bus. See Section 3.5 for detailed information on GPIB operations with the PPM. 

Although software written for the 1018B series would not take advantage of many of the new features of 

the PPM, the emulation capability can allow work to continue while new software is being written for the 

PPM. 

☛ NOTE: To use the 1018B software with the PPM in the 1018B Emulation Mode, the 

software must be written so that the talk and listen addresses of the PPM are both the same. 

For further information, see Section 3.5. 

2.18.2 Initiating the 1018B Emulation Mode 

To initiate the 1018B Emulation Mode, press [MENU] (8) [F2]. 

Thereafter, MENU (8) selects settings relating to the way in which the PPM will emulate the 1018B. See 

the Menu-8 listing in Appendix B for a listing of available settings. To know which selections to make, 

three questions must be answered regarding how the 1018B is presently being used on the IEEE Bus. 

These are: 

1. Is SRQ Enabled or Disabled? 

2. Is the instrument set up to output data upon being talk-addressed (automatic trigger reset), or 

does the instrument require a trigger reset (a GET or ? command) to take a data point? 

The 1018B emulation is incompatible with the Ratio Mode, and once the routine is in the 1018B 

Emulation Mode, the Fast Analog Output function cannot be accomplished. For further 

information, see Section 3.5. 

3. What is the Talk/Listen address? (they must be the same.) 

Based on these questions, use MENU (8) to select the appropriate settings. Press [MENU] (6) [F3] to set 

the PPM listen and talk addresses. 

Once the above has been done, it should be possible to swap a Model 1018B with option 05 (GPIB) with 

a Model 8501A or 8502A meter and continue operations. 

To terminate the 1018B Emulation Mode, press [MENU] (10) [F2]. 






3 


3.1 Introduction 

This chapter describes remote operation of the Series 8500A Peak Power Meters using the General 

Purpose Interface Bus (GPIB), and provides all of the basic information required to begin programming 

as easily as possible. After you are familiar with the Model 8501A/8502A Peak Power Meter (PPM) 

commands and functions, controlling the instrument through the GPIB should be fairly simple. A 

first-time user of the PPM should read the General Information in Section 3.2 before attempting to 

operate the PPM over the GPIB. 

Appendix A to this manual contains a summary of command codes. 

This chapter contains the following information: 

• General Information; Bus Functions; Menus; Modes of Operation; IEEE Output Modes; String 

Formats; Data Formats; Descriptive material on how the PPM functions over the GPIB; 

Simple Sample Programs 

• Command Descriptions by Function; Command Syntax; Sample Programs 

• Service Request (SRQ) Functions; Error Conditions 

• Giga-tronics Model 1018B Emulation; Limitations; Explicit and Implied 1018B Emulation 

• Status Code Values - Normal; Command Errors; Operation Errors; Task Completion Codes, 

Normal and Abnormal; Critical Errors 

• Summary of Bus Functions Implemented on the Model 8501A/8502A Power Meters 

• Command Summary Table (Alphabetical Listing) 

The PPM allows several modes of GPIB operation. Power measurements can be taken in a variety of 

modes and formats. These range from simple CW measurements to complex graphic display capabilities 

of pulse profiles, complete with timing information. 

The 1018B emulation feature allows the 8501A/8502A to be installed in most test systems where the 

1018B was previously used, without the need for immediate reprogramming. The emulation can facilitate 

the usage of the PPM with the older 1018B software while writing new codes is under way. 




3.2 Remote Operating Modes 

This section describes the various methods and modes that are used for remotely controlling the PPM 

through the GPIB. Typical sample programs illustrating the use of commands are provided. 

3.2.1 PPM IEEE Bus Functions 

Remote operation of the PPM is accomplished through the GPIB under the control of a remote 

controller/calculator. Bus functions are implemented using the notation of the IEEE-488 1978 

specification. These are given in the Bus Functions Summary in Section 3.7. 

The following is the general order of events when operating through the GPIB: 

1. Parsing of Command String. 

2. Actions taken: 

a. Autoscale, if requested. 

b. Power measurement, and so forth. 

c. Output of data upon TACS (Talker Active State) 

It is necessary to wait for certain events to complete before sending new commands. Examples of such 

commands are AUTO and Marker Placement. If the PPM is placed in TACS and then untalked or if a new 

command string is sent, then the taking of data will be terminated as will the autoscale function if it is 

not yet complete. Failure of autoscale will result in a service request and the error condition of 60. 

Completion will be signaled by the SRQ reporting either success or failure. If the command is AUTO and 

Marker Placement, it is necessary to wait for AUTO success or failure, and then Marker Placement 

success or failure before expecting any time measurement output data from the PPM. 

The controller should time out if the PPM does not complete the appropriate service requests in a 

reasonable amount of time; allowing for the autoscale average number, pulse repetition rate, etc. 

It is recommended that commands be sent after Device Clear from the controller to guarantee the state of 

the instrument. See Section 1.3 for the default settings. 

Any pulse profile related command (DUMG, Plot commands, and marker placement commands) will 

perform their operation on the collected data when they are received. 

Throughout this IEEE Bus operation, delays handled as arguments to commands sent to the PPM are 

listed as nnnnnn.nn µs. The PPM will accept resolution down to 0.1 ns or 0.0001 µs. A total of eight 

digits are allowed. The position of the decimal point can vary. Arguments should not be sent with excess 

digits to the right of the decimal point. 




3.2.2 Front Panel Menus 

See Appendix B for a listing of menus that can be accessed with the front panel MENU and MEM keys. 

Appendix C contains illustrations of top level menu formats. 

Before attempting to control the PPM over the GPIB, it should be kept in mind that there are various 

front panel menu selections that will affect bus activity. The front panel menu selections relating to the 

GPIB will include the following capabilities: 

1. Enter the PPM address 


☛ NOTE: This is most important as the PPM will not respond to bus commands unless this 

has been correctly accomplished. 

2. Enter the plotter address 


The address entries are self-explanatory; valid values are 0 to 30. The addresses entered are 

stored in non-volatile memory and need to be entered only when they change, but not when 

power is turned off and on again. 

3. Emulate 1018B (see Section 3.5). The instrument will always power-on in the normal PPM mode 

and not the 1018B emulation mode. 

4. Plot (see Plot Output Mode in Section 3.2.5). 

5. Stop current plotting activity (see Stand Alone Plot Output Mode in Section 3.2.5). 

3.2.3 Power-On Condition 

When the PPM is first turned on, it will automatically go into its Power-On Self-Test (POST) function. 

When POST has completed, the routine returns to the last setup before the instrument was powered off. 

After POST, the instrument will be ready to receive instructions from the GPIB controller to go to the 

Remote state. 

The address to place the PPM in Remote at power-on will be the same address that was used before 

power-off (the default address is 4). 




3.2.4 Remote and Local Lockout Functions 

The PPM accepts commands or output data only through the bus when it is in the Remote state. It is 

placed in the Remote state by listen-addressing the instrument with REN asserted, per the IEEE-488 1978 

standard. The PPM will ignore talk-addressing when it is not in the Remote state. Any Group Execute 

Trigger (GET) command or any data sent to the instrument when it is addressed while not in Remote will 

result in an error condition, and a service request will be generated if SRQ is enabled. 

When in the Remote state, the front panel keys will not be active except for an escape sequence to return 

to local control. The escape sequence is initiated by pressing [MENU]. At that time the PPM will suspend 

all operations, including IEEE Bus interaction. The measurement being displayed on the front panel will 

be replaced with a prompt to press F1 to return to local control, or F2 to abort the local escape sequence. 

The instrument will not respond to any other keystrokes. If F1 is pressed, the instrument will return to 

local control and resume normal manual operation. If F2 is pressed, the instrument will resume normal 

operations in the Remote state as though no action had occurred. Once the unit has been returned to 

Local control, it will return to Remote control the next time it is Listen-Addressed (LADS) with REN 

asserted. 

Another method to return to Local is achieved by sending a GTL (Go To Local) command from the GPIB 

controller. The PPM will return to the Local control state when it receives this command, and can then be 

returned to the Remote state the next time it is listen-addressed with REN asserted. 

Besides the return to local escape sequence and the GTL universal command, the PPM will also exit the 

Remote state when the REN line goes low. 

After the PPM has entered the Remote state, a Local Lockout command can be sent to disable the use of 

the front panel. This feature is intended to prevent accidental changes in front panel settings or 

interruption of the program. 

When the instrument is in the Local Lockout mode, the Return to Local escape sequence activated by the 

MENU key is disabled. There is no way to regain control from the front panel once Local Lockout has 

been commanded. 

To go to the Local Lockout mode, the Local Lockout (LLO) bus command must be sent to the PPM. The 

LLO light on the PPM’s front panel will not be turned on at that time, but the instrument will be in the 

LLO state. At the next change in the state of the instrument, either a change in the addressed state of the 

PPM on the GPIB or any keystroke made on the front panel, the LLO light will turn on. If a front panel 

keystroke is made, it is ignored and will not affect the state of the instrument. Subsequent attempts to 

control the unit from the front panel will also be ignored. 

3.2.5 Output Modes 

The PPM outputs data over the GPIB in the following six output modes: 

• Update Trigger Reset 

• Update Data Continuously 

• Plot 

• Temperature Difference 

• Status Byte 

• Stand Alone Plot 

The PPM can be in only one output mode when it is talk-addressed. For example, the unit cannot be 

programmed to plot and then immediately output the difference in temperature since the last calibration. 

If the PPM receives more than one output mode instruction, the most recent command will supersede all 

previous output commands. 




The instrument must always be in an output mode. It sends output information when it receives a 

command to initiate another output mode, or when a current output mode is completed and terminates 

itself. The self terminating modes are Plot, Output Temperature Difference Since Calibration, Output 

Status Byte, and Stand Alone Plot. When these modes complete, the PPM will not send any more data 

until it is untalked (the Stand Alone Plot untalks itself). When untalked, the default output mode becomes 

either Update Data Trigger Reset or Update Data Continuously, depending on which mode was last 

initiated. When power is first applied to the instrument, the default output mode is Update Data Trigger 

Reset. 

Before selecting any of the PPM Output Modes described above, required parameters should be set so 

that the PPM data that is taken will be valid. For example, plotting commands will not work unless the 

PPM has been set to the Graph Mode. 

Update Trigger Reset Output Mode 

A string of four characters (UPDT) must be sent over the bus to the PPM to access this mode of 

operation. If you are using BASIC on an HP Series 200 computer, the command might look like: 

where: 

OUTPUT 704; UPDT 

OUTPUT is the GPIB command to send the letters following the semicolon. 

The 7 in 704 is the HP instruction that the output is to go via the GPIB interface. 

The 04 in 704 is the Listen/Talk address of the PPM. The Listen/Talk address must be set with 

the MENU key on the PPM’s front panel (see the Menu (6) description in Appendix B). 

In the Update Trigger Reset Mode, the PPM will not send any data until it receives a trigger reset. When 

the trigger reset is received through the GPIB, the instrument is set to record the next measurement. If the 

instrument is in the Peak or Graph Mode, the measurement (power reading at the cursor location) will be 

taken the next time the instrument is triggered. Triggering can be either internal or external, depending on 

how the instrument has been configured. The recorded measurement data will be output through the GPIB 

when the PPM next enters TACS (Talker Active State). 

The trigger reset can take one of the following two forms: 

A. The universal GPIB command, GET (Group Execute Trigger), can be sent over the bus when the 

PPM is listen-addressed, or 

B. The controller can send the UPDN (Up-date Data Now) command to transfer the last data taken to 

the GPIB buffer (e.g. OUTPUT 704; UPDN). 

When the PPM completes the measurement and has the data ready to output, it will request service if it is 

not in TACS and has SRQ enabled. Entering TACS will clear the service request if the instrument has not 

already been serviced directly by the GPIB controller program. 




The procedure to trigger reset the PPM with the GET command consists of the following steps: 

1. Listen-address the PPM. 

2. Send the GET universal command. 

3. Talk-address the PPM. 

4. Release ATN to set the PPM in TACS. 

If in the Peak Mode, send the pulse to trigger the PPM. 

If the pulse is sent before the PPM is in TACS, an SRQ will be generated if SRQ has been 

enabled. Entering TACS will clear the SRQ. 

5. Read the power measurement string as it is sent by the PPM. The string will be terminated with a 

carriage return followed by a line feed character sent with EOI. 

The procedure to trigger reset the PPM with the UPDN command is the same as using the universal GET 

command except that after Step 1 when the PPM has been listen-addressed, the command string UPDN 

should be sent. The power measurement data output format is discussed in Section 3.2.7. 

Sample Program: 

10 PRINT CHR$(12); 

20 ! THIS PROGRAM USES THE 

30 ! UPDATE TRIGGER RESET MODE 

40 ! OF THE PPM TO COLLECT 

50 ! POWER MEASUREMENT DATA. 

60 ! UPDN RESETS THE PPM. IT 

65 ! IS THEN READY OR ARMED. 

70 ! THE PPM WILL SEND DATA 

80 ! AFTER RECEIVING THE UPDN 

90 ! COMMAND. 

100 ! 

110 ! DATA ENTERED AS A STRING 

120 ! D$ IS DISPLAYED, AND THEN 

130 ! REPEATED CONTINUOUSLY. 

140 ! 

150 OUTPUT 704; UPDT 

160 OUTPUT 704; UPDN 

170 ENTER 704;D$ 

180 DISP D$ 

190 GO TO 160 

200 END 

☛ NOTE: In the Dual Channel Mode, it is necessary to read the IEEE Bus twice to get A and 

B channel data. 




Update Data Continuously Output Mode 

A string of four characters (UPDC) must be sent to the PPM to access this mode of operation: 

If you are using BASIC with an HP Series 200 computer, the command might look like: 

OUTPUT 704; UPDC 

where: 

OUTPUT is the GPIB command to send the letters following the semicolon. 

The 7 in 704 is the HP instruction that the output is to go via the GPIB interface. 

The 04 in 704 is the Listen/Talk address of the PPM. This address must be set from the front 

panel with the MENU key (see the MENU (6) description in Appendix B). 

In the Update Data Continuously Mode, the PPM is ready to send a continuous stream of data points 

while it is in TACS (Talker Active State). Upon entering TACS, the PPM will initiate a trigger reset and 

be ready to record the next measurement. If the instrument is in the Peak or Graph Modes, the 

measurement (power reading at the cursor location) will be taken the next time the instrument is 

triggered. Triggering can be either internal or external, depending on how the PPM has been configured. 

Upon continuous triggering, measurement data points separated by commas will be sent by the PPM. 

Measurement data will continue to be sent through the GPIB, separated by commas, every time a trigger 

occurs until the instrument has been untalked. 


10 ! THIS PROGRAM USES UPDC 

20 ! UPDATE DATA CONTINUOUSLY. 

30 ! THE DATA IS SENT BY THE PPM 

40 ! WHEN IT IS TALK ADDRESSED 

50 ! WITH THE ENTER STATEMENT 

60 ! 

70 OUTPUT 704; UPDC 

80 ! 

90 ! TAKE 10 READINGS AND 

100 ! DISPLAY THEM: 

110 FOR I=1 TO 10 

120 ENTER 704 USING K,#;A$,A(I) 

130 DISP A(I) 

140 NEXT I 

150 END 




Plot Output Mode 

In this mode the PPM sends HPGL plotter commands to plot a pulse on a compatible plotter. The PPM 

command PLOT initiates the capturing of a pulse and relevant information that will be plotted when the 

PPM enters TACS. The procedure to plot a graph over the GPIB consists of the following steps: 

1. Prepare the PPM by entering the Graph Mode and obtaining the desired pulse profile to be 

plotted as shown in the PPM’s display window. Also select which sub-mode you want because 

the data shown on the plot is different for each sub-mode. For example, selecting the Marker 

sub-mode will cause the marker values to be shown at the bottom of the plot. 

2. Send the PLOT command to the PPM. 

3. Listen-address the plotter. 

4. Talk-address the PPM. 

5. Release ATN, putting the PPM in TACS. 

The PPM will terminate the plot with a carriage return followed by a line feed sent with EOI. If 

necessary, the plot can be aborted by the untalking of the PPM during transmission of the plot. 

Whenever the PLOT command is sent to the PPM while it is in the Graph Mode, the PPM will plot a 

graph of the selected Cursor, Pulse, or Marker sub-mode. See Figures 2-8, 2-10 and 2-9 for typical plots 

of Graph sub-mode pulse profiles. 

The following commands are used when it is desired to have any serial or code numbers appear on a 

hardcopy plot. 

PLPNxxxxxx...... 

(x = string of 12 or less characters 

Plot part number, ASCII string) 

PLCNxxxxxx...... 

(x = string of 12 or less characters 

Plot code number, ASCII string) 

Any printable character is allowed, including spaces, except that all leading spaces prior to the first 

non-space character are stripped off, and not included in the number of characters in the string. The 

string must be terminated by a semicolon which is not printed. Therefore, no semicolons can be 

contained within a label string. 


10 ! THIS PROGRAM DEMONSTRATES 

20 ! HOW TO MAKE THE PPM OUTPUT 

30 ! A PULSE PROFILE DISPLAYED 

40 ! IN THE GRAPH MODE TO A 

50 ! DIGITAL PLOTTER. 

60 ! 

70 ! C$ AND P$ ARE STRINGS 

80 ! THAT CAN BE SENT SO THAT A 

90 ! CODE NUMBER & PART NUMBER 

100 ! ARE PRINTED ON THE PLOT BY 

110 ! THE PPM. 

120 ! 

130 C$=ABCDEFGHIJKL 

140 P$=123456789012 

150 

160 ! AFTER ENTRY INTO THE GRAPH 

170 ! MODE, THE FOLLOWING 




180 ! COMMANDS WILL INITIATE THE 

190 ! PPM’S PLOT ROUTINE. THE 

200 ! ADDRESS OF THE PLOTTER AND 

210 ! PPM MUST BE SET CORRECTLY - 

220 ! IN THIS CASE THE PPM IS AT 704, 

230 ! AND THE PLOTTER IS AT 706. 

240 OUTPUT 704;PLCN&C$ 

250 ! SEND CODE NUMBER TO PPM 

260 OUTPUT 704;PLPN&P$ 

270 ! SEND PART NUMBER TO PPM 

280 

290 ! THESE ARE THE COMMANDS TO 

300 ! INITIATE THE PLOT ROUTINE: 

310 

320 OUTPUT 704;PLOT 

330 ! (PUTS PPM IN PLOT OUTPUT MODE) 

340 

350 SEND 7;UNL 

360 SEND 7;LISTEN 6 

370 ! (LISTEN ADDRESSES THE PLOTTER) 

380 SEND 7;TALK 4 

390 ! (TALK ADDRESSES THE PPM) 

400 

410 SEND 7;DATA 

420 ! (RELEASES ATN LINE ALLOWING 

430 ! PLOTTING TO BEGIN) 

440 

450 WAIT 180 

460 ! WAIT UNTIL PLOTTING HAS 

470 ! FINISHED BEFORE UNTALKING 

480 ! THE PPM. PLOT TAKES ABOUT 

490 ! 3 MINUTES 

500 

510 ! UNTALK AND UNLISTEN ALL BUS 

520 ! DEVICES 

530 SEND 7;UNT UNL 

540 END 




Temperature Difference Output Mode 

This mode determines the difference in temperature for each detector since it was last calibrated. The 

mode provides a means to maintain measurement accuracy by allowing the software to determine when a 

detector Self-Cal is required. If detector temperature difference information is desired, the command 

DTMP is sent to the PPM. The instrument will then be ready to output a data string in the following 

format (x and y = temperature reading digits; s = polarity): 

DTPAsxx.x,DTPBsyy.y(CR)(LF-EOI) 

This will be true with both the Model 8501A and 8502A instruments. If a detector is not present, the 

digit portion of the string will read +00.0. The zeros can either mean no change in temperature difference 

or no detector present. With the 8501A, the B reading will always be zeros. 


Status Byte 

10 ! THIS PROGRAM EXTRACTS 

20 ! TEMPERATURE INFORMATION 

30 ! FROM THE PPM SO THAT A 

40 ! CONTROLLER CAN DETERMINE 

50 ! IF A SELF-CAL IS REQUIRED. 

60 ! IF THE TEMP SINCE LAST SELF- 

70 ! CAL IS MORE THAN +/-5 DEG-C, 

80 ! SELF-CAL IS RECOMMENDED 

90 DIM A$(19) 

100 

110 

120 OUTPUT 704;DTMP 

130 ENTER 704;A$ 

140 DISP A$ 

150 END 

The PPM uses this mode to send its status byte as a character string. The value sent is the internal status 

value. It is not exactly the same as the byte sent during a serial poll in which bit-7 is high when service 

is being requested (see Service Requests in Section 3.4). The character string sent out to represent the 

status value will consist of a four character head, STAT, followed by three digits. This output mode can 

only be active when SRQ is disabled. Service request status bytes are not buffered when SRQ is disabled, 

so only the most recent status value will be output. The status value is followed by a carriage return, 

followed by a line feed sent with EOI. 

Stand Alone Plot Output Mode 

Plotting Without Using a Controller: 

The PPM uses this mode to send HPGL digital plotter commands to plot a pulse, much as it does in the 

Plot Mode. The difference is that stand alone plots are initiated by commands from the front panel of the 

PPM. This is to allow plotting without the use of a controller (see Digital Plotting of Graphic Data in 

Section 2.9). 

Stand Alone Plot Output Mode: PPM Internal Procedures: 

These actions are performed by the PPM when the Stand Alone Plot is initiated from the front panel. 

Before the PPM can output plotter information, it is necessary to first enter the Graph Mode of operation. 

Chapter 2 of this manual contains the information required to prepare for and produce digital plots of 

Graph Mode and Marker sub-mode data. The following paragraphs describe the PPM’s internal 

procedures for GPIB interaction when front panel plots are to be made. 




When the PPM has drawn a complete pulse profile on its display, it is ready to act as a GPIB controller. 

When the plot routine is activated, the PPM checks to make sure that there is no other active controller 

on the bus. If the PPM is in the Remote state, it implies that a controller is present and registers as a 

GPIB bus error. Also, all PPM service requests are generated by action on the GPIB, and are cleared 

when REN is not asserted (see Remote and Local Lockout in Section 3.2.4). Therefore, if the PPM 

internally detects any abnormal status condition in its status byte, it will assume that there was recent 

activity on the bus involving a controller and refuse to proceed further with the plot. It will also attempt a 

service request to see if there is any response from the controller. 

If the PPM does not detect an indication of another controller, it will assume that it is the only 

controller-capable device on the bus, and will act as the system controller. Depending on the system 

configuration, these checks made by the instrument may not be perfect. 

☛ NOTE: For proper system operation, no active controller can be on the bus when the front 

panel function is initiated. 

While the PPM is checking the state of the bus, it will display the message Checking GPIB Interface, and 

the keyboard will be inactive. 

If the PPM does detect an indication of a controller on the bus, or if the PPM takes control of the bus and 

attempts to address the plotter but does not get a handshake, a GPIB bus error message will be displayed 

and a prompt will require F2 to be pressed to continue. If the PPM does not detect a bus error, a beep 

will sound and normal operation will resume while the plot is being sent over the GPIB. Once plotting 

has begun, control of the front panel will be returned to local. 

☛ NOTE: If you want to add serial and code numbers to the plot, use the procedure for 

Making Plots in Section 2.9. 




3.2.6 Command String Format 

Control of the PPM is accomplished by using four-character mnemonic commands. Some of these require 

one or more numerical entries (arguments). The command structure is intended to be taken literally; there 

are no optional formats. Thus, if two arguments are specified for a command, both must be given for the 

command to be processed. 

A character string is terminated with a line feed character and/or an EOI. Carriage returns are ignored. 

Therefore, a carriage return/line feed sequence will act as a string terminator and will be treated as a line 

feed. More than one command (and respective arguments) can be sent in a command string as long as the 

string does not exceed 128 characters, including the terminator. If an EOI is sent and the last character is 

not a line feed, only 127 characters can be sent. None of the commands can be processed until the string 

is terminated, and then they will be processed in the order they were given (see Output Modes in 

Section 3.2.5 regarding conflicting output commands). 

When the command string is received, it is first checked for syntax and numerical values, and commands 

are reviewed to make sure they are valid. If a syntax error or an invalid data error is detected, or the 

execution of the command string would lead to an operation error, then none of the commands will be 

executed and a service request will be generated if SRQ is enabled. 

A very forgiving syntax is allowed since the PPM can distinguish between any command and any 

argument, with no separator character required between commands or a command and its argument. The 

only time a separator character is required is between arguments when the command has two or more 

arguments. A separator is defined to be a space, a comma, or a semi-colon. Any number of separators are 

allowed before the first command, between a command and an argument, between arguments, between 

the last argument of a command and the next command, or at the end of the string without effecting the 

PPM’s interpretation of the command string. Commands can be in upper or lower case format. 

An argument consists of a digit string which can optionally be preceded by a positive (+) or negative (-) 

sign. If no sign is present, the number is assumed to be positive. The digit string can also contain a 

decimal point if desired. The dimension of each argument is fixed, therefore no dimensional identifier is 

needed or allowed, only a number. This will be described in the command description to follow. 1018B 

command arguments follow a different format as is discussed in Section 3.5. 

3.2.7 Power Measurement Data Output Format 

The measurement data output formats transmitted by the PPM over the GPIB depend on whether the PPM 

is in the dBm or W power mode of operation. These modes are entered by using GPIB commands as 

described in Section 3.3.3 or, when the PPM is not in the Remote mode, by pressing [dB/mW] on the 

front panel. 

Power measurements over the GPIB are taken only during the Update Trigger Reset or Update Data 

Continuously output modes (see Section 3.2.5). 

To initiate a power measurement over the GPIB, a command is sent to the PPM from the controller and 

then talk-addressed. When the PPM is triggered, it will transmit its data through the GPIB to the 

controller. See the following command descriptions for the commands required to take data. The 

measurement data strings are discussed in subsequent sections. 

Log (dBm) Data Format 

When the PPM is in the dBm mode (as indicated in the display), the first three letters of the data string 

are DBM. This indicates that the data represents a dBm value. The following letter indicates which 

detector (channel A or B) was taking the measurement. This is followed by a polarity sign, and then a 

string of five digits with a decimal point after the third digit. 

Each measurement taken in the Update Trigger Reset Mode will be terminated by a carriage return 

followed by a line feed sent with EOI. Measurements taken in the Update Trigger Continuously Mode 

will be separated with commas. Examples are: 




Update Trigger Reset Mode: 

DBMA-012.73(CR)(LF-EOI) 

DBMB+002.47(CR)(LF-EOI) 

Update Data Continuously Mode: 

DBMA+016.74 

DBMA+018.23 

DBMA+017.34 

(and so on) 

The actual measurement string (less terminating and delimiting characters for each data point) will 

always be 11 characters long. 

Linear Power Data Format 

When the PPM is in the linear power mode (as indicated in the display), the first three characters of the 

data string will be PWR. This indicates that the measurement is a linear value, with the units always in 

WATTS. As with DBM, the next character indicates which detector (channel A or B) was taking the 

measurement. This is always followed by a value in engineering notation. The value consists of four 

digits and a decimal point. These are followed by an E, then a polarity sign and two more digits. The 

digits following the E are always multiples of three. This makes it easier to determine if the data is being 

given in terms of microwatts, milliwatts, nanowatts, etc. 

Each measurement taken in the Update Data Trigger Reset mode will be terminated by a carriage return 

followed by a line feed sent with EOI. Measurements taken in the Update Data Continuously mode will 

be separated by commas. Examples are: 

Update Data Trigger Reset mode: 

PWRA31.61E-06(CR)(LF-EOI) 

for 31.61 microwatts 

PWRB634.7E-03(CR)(LF-EOI) 

for 634.7 milliwatts 

Update Data Continuously mode: 

PWRA64.98E-06, 

PWRA65.23E-06, 

PWRA89.32E-06, 

and so on 

The actual measurement string (less terminating or delimiting characters for each data point) will always 

be 13 characters long. 




3.3 GPIB Command Descriptions 

There are approximately 100 different commands available to program the 8500A for use on the GPIB. 

This section provides functional information pertaining to the commands with the least complex material 

covered first. 

For most applications the automatic features of the PPM provide easy methods of making pulsed 

measurements. However, a great deal of flexibility and control is available if you prefer to work with raw 

data. 

An alphabetical listing of all commands is in the Command Summary in Table 3-3. 

The PPM has the following general capabilities: 

• The ability to measure and output CW or Peak power, or a Ratio of two signals in Linear 

(Watts) or Log (dBm) format. 

• In some applications, the PPM can output the microwave frequency at which the power 

measurement is being taken. 

• Graphically display pulse profiles automatically. 

• Markers can be defined on the pulse. 

• Rise time, fall time, and pulse width can be measured and output automatically. 

• Time differences between selected markers can be measured and output automatically. 

• Self-test capabilities are built in. 

• The PPM Calibration function automatically linearizes the detector over a 50 dB power range 

for the most accurate power measurements. 

• The temperature of the detectors can be monitored to verify whether the detector should be 

calibrated. 

• The PPM makes use of a PROM with stored frequency response data contained in the RF 

detector assembly. The instrument uses the stored data to automatically compensate for 

detector frequency response variations. A rear panel connector is available on the unit to 

connect a V/GHz (V α F) signal to allow for automatic frequency selection and correction of 

measured power. 

• The use of balanced detectors enhances accuracy when used in situations where even 

harmonics are present. 

• Setups can be stored or recalled to and from the PPM’s non-volatile memory by GPIB 

commands as well as manually through the front panel. 

• Graph displays can be plotted on digital plotters. In addition, data pertaining to a pulse profile 

can be output to the controller. 

• A Data Fast mode disables the front panel display, allowing faster bus operation. 

• Frequency information can be hidden when the PPM is used for classified testing. 

☛ NOTE: The Model 8501A instrument will respond to the same command sets as the Model 

8502A. The only exception is that the 8501A responds only to commands relating to 

channel A. 




Instrument functions that take a specific amount of time to complete will be noted with an asterisk (*) in 

the following discussion. 

During the time the PPM is processing a function such as calibration, zeroing, or self test, the instrument 

will continue to be active on the bus. Any new commands may not be received if previous activity is not 

already completed. No output will be given and, if any commands are sent by the controller, only the first 

byte will be accepted. The PPM will then send Not Ready for Data until the function is complete. 

When the particular function completes, the PPM will request service and send SRQ if SRQ has been 

enabled. Successful completion of the task is verified by checking the value of the status byte. A listing 

of Status Codes is given in Section 3.6. If SRQ has not been enabled, the controller can only learn the 

result of the operation by asking for the status byte with the STAT command. 

3.3.1 Common Mode Functions 

Calibration Commands 

It is advisable to use the PPM’s SRQ capabilities to monitor whether the calibration has completed and is 

successful or not. A serial poll can be conducted and the returned Status value interpreted. See 

Section 3.4 for SRQ features, and Section 3.6 for applicable Status Code values. 

* CALA Calibrate channel A detector 

* CALB Calibrate channel B detector 

Temperature Difference Since Last Calibration Commands 

DTMP 

Output the Difference in the temperature of each detector since calibration. This 

command causes the temperature to be read from each detector (or whatever detector 

is connected). It will be formatted as described under Temperature Difference Output 

Mode in Section 3.2.5, and is useful for determining whether recalibration of 

detectors should take place. Normally the PPM can maintain accuracy within ±5 °C 

of the temperature of calibration. 

Autozero Detectors Commands 

* ZERA Zero channel A detector 

* ZERB Zero channel B detector 

Store or Recall Setup Commands 

STORnn Store current PPM settings in non-volatile setup memory number n. 

n = number between 1 and 10. 

RECLnn 

Recall PPM setting from non-volatile memory n, and make it the current setting. 

n = number between 0 and 10. Setup number 0 cannot be used for storage. It is the 

last setup before power was turned off or the PPM received a Device Clear from the 

GPIB controller. 

Hide and Unhide Frequency Information Commands 

FQHD 

FQDS 

Hide the frequency information 

Display the frequency information 




Output Status Byte Information Command 

STAT 

Typical Program Lines: 

OUTPUT 704;STAT 

ENTER 704;A$ 

PRINT A$ 

SRQ Related Commands 

Output status byte. This command will only be effective when SRQ is disabled. If it 

is received while SRQ is enabled, a service request will be generated. 

SRQE 

SRQD 

UNDD 

UNDE 

Enable SRQ 

Disable SRQ 

Disable SRQ only for under-range conditions. (Permits continuing data output 

without undesired SRQ interference.) 

Enable SRQ for under-range conditions. 

Power Limits 

The purpose of setting power limits is to alert the controller of two possibilities having occurred. These 

are: 

A. Over-range: Warns that the detector (or other component) may have been damaged, and data taken 

may be invalid. 

B. Under-range: Warns that the power level being measured is low and may be inaccurate. 

The PPM can be enabled to generate an SRQ for under-range conditions. The point at which the PPM 

sends an SRQ is determined by the MINP command. Data output during an under-range condition is as 

follows: 

Log Mode: -99.99dBm 

Linear Mode: 0.000E-99 

Over-range conditions always generate an SRQ (if SRQ is enabled), but normal data is still output. It 

should be kept in mind that if the detector is exposed to power levels in excess of +23 dBm, not only will 

the PPM’s measurement accuracy be degraded, but damage or complete destruction of the detector’s 

diode element can occur. 

The commands for setting power limits are: 

MAXPsnn.nn 

MINPsnn.nn 

Set power level (in dBm) for over-range condition. 

s = polarity; n = dBm; +21.00 max, -10.00 min. 

Set power level (in dBm) for under-range condition. 

s = polarity; n = dBm; -15.00 max, -50.00 min. 




3.3.2 Measurement Data Correction 

The manner in which the PPM is able to make very fast peak power measurements is dependent on the 

usage of zero bias schottky diode detectors as power sensing elements. These diodes have typical 

rise-times of less than 10 nanoseconds making them useful for pulsed RF applications. However, at 

microwave frequencies, it is necessary to compensate for the detector’s non-linearity with frequency. 

Each Giga-tronics detector used in the PPM has a built-in PROM which contains frequency correction 

data. Depending on the mode of operation, the PPM can be instructed to automatically subtract out the 

frequency non-linearity error from the power measurement being made. 

The PPM needs to know the frequency of operation for this automatic correction to take place. This can 

be done at the front panel, over the GPIB, or by the use of the Voltage Proportional to Frequency feature 

(V α F). The V α F is an analog voltage connected to the PPM’s rear panel EXTERNAL FREQUENCY 

input connection. A voltage is usually available from most sweepers called V/GHz with a coefficient of 

1V/GHz. This voltage can be converted to digital information by the PPM, and used as a frequency input 

instead of having to enter it by some other means. 

In addition to automatic frequency correction, it may be desired in some applications to use manual 

corrections based on specific measurements rather than the factory-supplied data in the detector’s PROM. 

This is known as Cal Factor. (Some power meters on the market use the term % efficiency, but it is 

basically the same thing.) Cal Factor is expressed in dB, and is the amount of power that must be added 

to or subtracted from the measurement so that the data will be correct. 

Another Data Modifier called Offset can also be used. Complex microwave test setups sometimes include 

attenuators or couplers to reduce high power signals to safe levels that can be measured by delicate 

instruments such as the PPM. The Offset feature allows the subtraction of residual attenuator or coupler 

errors from the measurement. 

The preceding Data Correction commands will be discussed in the following sections. 

Detector PROM Correction: User Supplied Frequency 

FREQff.ff 

(Where ff.ff is the frequency of the correction.) 

Correction is determined by taking a user-supplied frequency (ff.ff) and referencing data in a PROM in 

the detector. 

Min Value: 0.01 GHz 

Max Value: 110.00 GHz 


10 ! THIS PROGRAM SETS THE 

20 ! FREQUENCY FOR DETECTOR 

30 ! RESPONSE CORRECTION FOR 

40 ! THE PPM 

50 ! 

60 F=5.25 ! PPM FREQUENCY SETTING 

70 ! 

80 ! SEND COMMAND TO PPM 

90 OUTPUT 704 USING 100; FREQ,F 

100 IMAGE 4A,DDD.DD 

110 END 




Detector PROM Correction: External Frequency 

(V/GHz/Freq Ref) 

FPRVvv.vv,ss.ss,mm.mm 

(Where v, s and m are the arguments to scale the voltage input at the PPM FREQUENCY INPUT 

connection.) 

Correction to be applied for the frequency response of the detector will be determined from three 

user-supplied values to properly reference data in the PROM in the detector. The three arguments are 

respectively: 

A. A coefficient representing the voltage proportional to frequency of the sweeper’s V/GHz or Freq Ref 

output: 

Min Value: 0.10V/GHz 

Max Value: 10.00V/GHz 

The most common values for this coefficient are 0.5 and 1.00V/GHz. Consult the instruction manual 

for the sweeper being used to obtain the correct coefficient. 

B. The minimum coefficient voltage corresponding to the minimum frequency of the sweeper: 

Min Value: 0.0V 

Max Value: +19.000V 

Example: If the sweeper’s V/GHz is 0.5V and the minimum start frequency is 2.0 GHz, then this 

value would be 2 x 0.5 = 1V. 

C. The minimum frequency of the sweeper: 

Min Value: 0 GHz 

Max Value: 110.00 GHz 


10 ! PPM EXTERNAL FREQUENCY MODE 

20 G=5 ! VOLTS/GHZ 

30 V=1 ! V/GHZ START FREQUENCY 

40 F=2 ! SWEEPER START FREQUENCY 

50 OUTPUT 704 USING 60;FPRV,G,V,F 

60 IMAGE 4A,3(DD.DD) 

70 END 




External Frequency (V/GHZ) and Output Frequency to Controller Command 

FPVOvv.vv,ss.ss,mm.mm 

(Where v, s, and m are the arguments required to scale the voltage input at the PPM’s rear panel 

FREQUENCY INPUT connection.) These are the same as described previously for FPRV. 

This command causes the same action as the FPRV command but in addition, asks the PPM to output to 

the controller the converted frequency information from the PPM’s rear panel external frequency input. 

☛ NOTE: When using FPVO and operating in the UPDC mode, there will be a stack build 

up. Old frequency and power data will be output in applications such as swept power 

measurements. 


10 ! PPM EXTERNAL FREQUENCY PLUS 

20 ! FREQUENCY OUTPUT MODE 

30 OUTPUT 704;UPDT ! SELECT OUTPUT 

40 ! MODE. SELECT EXTERNAL FREQ 

50 ! MODE AND COLLECT A DATA 

60 ! POINT AND ITS FREQUENCY 

70 G=5 ! VOLTS/GHZ 

80 V=1 ! V/GHZ START FREQUENCY 

90 F=2 ! SWEEPER START FREQUENCY 

100 IMAGE 4A,3(DD.DD) 

110 OUTPUT 704 USING 100;FPVO,G,V,F 

120 TRIGGER 704 

130 ENTER 704 USING 4A,7D,X,4A,6D;A$,B,C$,D 

140 PRINT USING K,;POWER ,A$, IS ,B 

150 PRINT USING K,;FREQ ,C$, IS ,D, GHZ 

160 END 




User-Defined Detector Calibration Factor Commands 

Detector calibration factor for channel A in dB (cc.cc): 

DCFAcc.cc 

Min Value: -9.99 dB 

Max Value: +9.99 dB 

Detector calibration factor for channel B in dB (cc.cc): 

DCFBcc.cc 




10 ! THIS PROGRAM SHOWS HOW TO USE 

20 ! THE PPM CAL FACTOR FEATURE 

30 ! 

40 ! CHANNEL A CAL FACTOR 

50 ! COMMAND FOR 2.56 dB: 

60 OUTPUT 704;DCFA;2.56 

70 ! 

80 ! CHANNEL B CAL FACTOR 

90 ! COMMAND FOR 2.56 dB 

100 OUTPUT 704;DCFB;2.56 

110 ! 

120 END 

Offsetting Measured Data: dB Offset Commands 

Channel A offset: 

OFFAsnn.nn 

(s = polarity; nn.nn = dB value) 



Channel B offset: 

OFFBsnn.nn 

(s = polarity; nn.nn = dB value.) 






3.3.3 Mode Selection and Control 

This section describes the various modes of operation available with the PPM, with the exception of the 

sub-mode functions of the Graph Mode. These are described in Section 3.3.5. 

Commands or functions that affect a specific mode of operation are either given or referred to in the 

following command listings. It should be kept in mind that it is sometimes possible to combine modes, 

therefore care must be taken to observe the rules and arguments set forth. 

Select Log or Linear Power Measurement Format Commands 

DBMW 

dBm measurement format display and GPIB output. 

WATT Linear measurement format (mW) display and GPIB output. 

Typical Program Line: 

OUTPUT 704;WATT 

Select Measurement Mode Commands 

(Except Graph and Ratio Modes) 

CW 

CWPA 

CWPB 

Power Commands 

CW power, channel A 

CW power, channel B 

CWAB CW power, channels A & B 

A CW related command is: 

AVCWnnn 

Select number of averages n for CW power measurements. Higher numbers reduce noise effects and 

stabilize readings at low power levels. 

(n = number between 1 and 999) 

Peak Power Commands 

The Peak Power Mode must be used very carefully. Power measurements in this mode depend on the 

occurrence of a trigger, and the positioning of the cursor on the pulse to be measured. For more 

information, refer to Selecting Peak Power Operation in Section 3.2.5. 

To enter the Peak Power Mode use: 

PKPA 

PKPB 

PKAB 

Peak Mode for Channel A only 

Peak Mode for Channel B only 

Peak Mode for Channels A & B 




Related Peak Power Commands 

AVPK 

Select number of averages, n, for Peak power measurements. Higher numbers will 

reduce noise effects and provide more stability at low power levels. 

(n = number from 1 to 999 - higher than 4 is recommended). 

TRGAsnn.nn 

TRGBsnn.nn 

TRGE 

Internal trigger level, channel A 

Internal trigger level, channel B 

(s = polarity; n = dBm) 

Min Value: -10.00 dBm 

Max Value: +16.00 dBm 

External triggering 

☛ NOTE: It is important to remember that no data can be taken in the Peak Mode unless a 

trigger is occurring. This is indicated by the flashing of the New Data light on the front 

panel. See External Triggering in Section 3.2.5. 

RDLAnnnnnn.nn 

RDLBnnnnnn.nn 

CDLAsnnnnnn.nn 

CDLBsnnnnnn.nn 


Set channel A reference delay. (Arbitrary timing point to which other timing 

measurements are related.) (n = microseconds) 

Set channel B reference delay. (Arbitrary timing point to which other timing 

measurements are related.) (n = microseconds) 

Min Value: 0 µs 

Max Value: 213999.97 µs 

Set channel A cursor delay. Sets timing position of the Cursor on the graphic 

display. The Cursor is the vertical line located where the power reading (CSR PWR) 

is being taken. [Timing is related to the Reference Delay (REF DLY)]. 

(n = microseconds; s = polarity) 

Set cursor delay for channel B. Sets timing position of the Cursor on the graphic 

display. The Cursor is the vertical line located where the power reading (CSR PWR) 

is being taken. [Timing is relative to the Reference Delay (REF DLY)]. 


Min Value: 0 - Reference Delay 

Max Value: 213999.97 µs - Reference Delay 

10 D=1 ! CURSOR DELAY IN 

20 ! MICROSECONDS 

30 ! 

40 ! CHANGE CHANNEL A CURSOR 

50 ! DELAY 

60 OUTPUT 704;CDLA;D 

70 ! 

80 ! CHANGE CHANNEL B CURSOR 

90 ! DELAY 

100 OUTPUT 704;CDLB;D 

110 END 




3.3.4 Commands for Retrieving Data From the PPM 

UPDC 

Select Update Data Continuously Mode. The PPM will output a continuous stream 

of power measurement data points separated by commas. Every time the PPM 

receives a trigger a new data point is added to the stream. The formats discussed in 

A and B below can then occur: 

A. When using the FREQ, CALA (A Cal Factor), CALB (B Cal Factor), or FPRV (Rear Panel 

Frequency Input) methods for detector frequency response correction (NOT FPVO), the PPM’s Linear 

Mode data output string for Channel A will be: 

PWRAnn.nnEsnn,PWRAnn.nnEsnn,PWRAnn.nnEsnn 

(n = linear power in watts; Esnn = exponent) 

This example shows a data string for 3 triggers. Subsequent triggers will produce more data points 

separated by commas in the form of PWRAnn.nnEsnn. If channel B is in use, the header before the data 

points would be PWRB instead of PWRA. 

The PPM’s dBm mode data output string for channel A will be: 

DBMAsnnn.nn,DBMAsnnn.nn,DBMAsnnn.nn 



separated by commas in the form of DBMAnn.nnEsnn. If channel B is in use, the header before the data 

points would be DBMB instead of DBMA. 

B. When using the FPVO (Rear Panel Frequency Input and Frequency Output) method for detector 

frequency response correction, the PPM’s Linear Mode data output string for Channel A will be in 

the following form: 

PWRAmm.mmEsee,FRQAfff.ffE+09,PWRAnn.nnEsee,FRQAggg.ggE+09 

(m = first power data point; 

f = first frequency data point; 

n = second power data point; 

g = second frequency data point; 

Esee = exponent for power in watts; 

E+09 indicates frequency is in GHz.) 


separated by commas in the form of PWRAnn.nnEsnn,FRQAfff.ffE+09. If Channel B is being used, the 

headers before the data points would be PWRB and FRQB. See above for a description of dBm header 

and data formats. 

UPDT 

Select Update Data Trigger Reset Output Mode. Prepares the PPM for power 

measurement data taking routines using UPDN. 

UPDN 

Update Data Now. Take a power reading when the next trigger occurs. This 

command is only operational if the PPM is in the Update Trigger Reset Mode. See 

UPDT. 

The PPM will output a single data point each time UPDN is received. The output formats are the same as 

those described under UPDC. If FPVO is being used, the frequency at which the power measurement was 

taken is also output. See UPDC and FPVO. 




3.3.5 Graph Mode GPIB Operation 

Using the Graph Mode instead of the Peak Mode allows autoscaling of a pulse, and provides you with a 

display of the pulse. The Pulse and Marker sub-modes allow automatic timing measurements to be made. 

You must first place the PPM in the appropriate sub-mode before using the timing measurement 

command. 

In the Graph Mode, the PPM can use a plotter to draw the shape of the pulse. In the Cursor sub-mode, 

the delay and trigger parameters are written on the plot. The Pulse and Marker sub-modes add the results 

of their respective timing measurements. 

Delay values used by the instrument (Cursor, Start, and Marker, but not Window) are all displayed and 

output relative to the Reference Delay at the time the delays are specified. When the Reference Delay is 

changed, it will effect all of the other indicated delay values. 

The real timing of the functions described above (relative to the trigger) remains the same, but the 

displayed and GPIB output times of these functions are all in relation to the Reference Delay. When the 

Reference Delay changes, the other delays change accordingly. For example, if the Cursor Delay was 5 ns 

and the Reference Delay was increased by 2 ns, the Cursor Delay would decrease to 3 ns. Therefore, 

Reference Delay entries should always be made first. Most applications and measurements will not 

require changing the Reference Delay from its default setting of 0.000 nanosecond. 

The information to be given next is in ascending order of complexity. All functions that provide results 

on an automatic basis will be covered first. This should reduce programming time by allowing the PPM’s 

internal software to take care of various tasks such as rise time. 

Obviously, there are some types of pulses that cannot easily be measured automatically. If it is required 

that algorithms be devised to extract pulse information, the PPM should serve this purpose well by using 

the manual commands and functions which will be covered later in this section. 

Graph Sub-Mode Selection Commands 

GRFA Select Graphic display mode (Cursor sub-mode), channel A. 

GRFB Select Graphic display mode (Cursor sub-mode), channel B. 

MRKA Select Marker sub-mode display, channel A. 

MRKB Select Marker sub-mode display, channel B. 

PULA Select Pulse Parameters sub-mode, channel A. 

PULB Select Pulse Parameters sub-mode, channel B. 

Automatic Functions of the Graph Mode 

The following commands will instruct the PPM to automatically carry out a procedure of some kind. In 

most cases, only instrument settings are made. In some cases, settings are made and appropriate 

information is output to the controller. 

When using the PPM’s graphic capabilities, it should be kept in mind that any operations are only 

applicable to Pulse measurements. All pulse operations require a trigger of some kind. Therefore, before 

attempting GPIB operations it is advised to become familiar with the manual operation of the PPM. To 

ensure that the instrument will trigger properly, the Internal Channel A, Internal Channel B, or the 

External Trigger function must be selected. 

☛ NOTE: Failure to trigger for any pulse operation over the GPIB will result in placing the 

PPM in a Waiting for Trigger state. 




Reading and Defining Pulse Parameters 

The following commands read the current values set for the pulse parameters: 

* PUFT Get Pulse Fall Time. The unit will respond with: 

FALAddddddE-e (If channel A selected) 

FALBddddddE-e (If channel B selected) 

(d = seconds; e = exponent) 

☛ NOTE: *PUFT, *PURT, and *PUWD operate only in the Graph Mode. 

* PURT Get Pulse Rise Time. The unit will respond with: 

RISAddddddE-e (If channel A selected) 

RISBddddddE-e (If channel B selected) 

(d = seconds: e = exponent) 

* PUWD Get Pulse Width. The unit will respond with: 

WIDAddddddE-e (If channel A selected) 

WIDBddddddE-e (If channel B selected) 

(d = seconds: e = exponent) 

The following commands set new values for the pulse parameters: 

PUFSddd Set Pulse Fall Time - Start %. 

Where d = % expressed in 0.1% units. Allowable range is 1 to 999 (0.1% to 99.9%) 

PUFEddd Set Pulse Fall Time - End % 

Where d = % expressed in 0.1 % units. Allowable range is 1 to 999 (0.1% to 99.9%) 

PURSddd Set Pulse Rise Time - Start % 


PUREddd Set Pulse Rise Time - End % 


PUWSddd Set Pulse Width - Start % 


PUWEddd Set Pulse Width - End % 





Automatic Window Delay Selection Related Commands (Autoscaling) 

* AUTO Autoscale Current Pulse Profile. If SRQ is enabled, it will be sent at the completion 

of Autoscaling. Successful Autoscaling can be determined by checking the value of 

the Status byte. 

AVASnnn 

Select the Number of Averages, n, for Autoscaling (1 to 999). This command can be 

useful when attempting to Autoscale a pulse in a noisy environment. The more 

stable the pulse to be Autoscaled is, the less averages required. This setting is 

independent of other averaging settings such as AVCW or AVPK. 

The number of averages set by this command is never reset to a default value (not 

even by a Device Clear command). Therefore, it is advisable to set the desired value 

prior to commencing the Autoscaling function, or to set it once at the beginning of 

the program and not change its value again. 

ASDLnnnnnn.n Select Maximum Expected Pulse Width for Autoscaling. The purpose of this 

command is to allow autoscaling of narrow pulses with high repetition rates. 

(n = 0.5 to 200,000 microseconds). 

The maximum expected pulse width set by this command is never reset to a default 

value (not even by a Device Clear command). Therefore, it is advisable to set this to 

the desired value prior to activating the Autoscale function. 

3.3.6 Marker Timing Measurements 

A trigger must occur on a consistent basis to make repeatable pulse measurements for profiling 

operations. Erratic pulse trains or profiles can lead to errors or confusion. In situations where pulse 

widths or repetition rates are likely to continually vary, it would be better to make single pulse 

measurements in the Peak Mode. However, to make single pulse measurements, you should know where 

the Cursor Delay should be set to make the measurement. 

The commands in the Automatic Timing description in this section allow for easy measurement of the 

most commonly desired pulse parameters. These include rise time, fall time, pulse width and 

combinations thereof. The automatic measurements are determined by conventions commonly used in the 

microwave industry. For example, rise time would be from the 10% to 90% power points on the leading 

edge of the pulse. However, there are still some gray areas which must be taken into account when you 

use these automatic timing functions. 

These gray areas include deciding what point on the pulse should be considered as the 100% power 

reference point for the PPM to use when determining the rise time, fall time, and pulse width. 

It is obvious that, in most situations, it is more desirable to use the center of the pulse as the reference 

point. Special situations can, of course, occur where the setting of the reference point would be somewhat 

arbitrary. 

The PPM handles the above problems in two ways. The first method is when Autoscaling is used. The 

Reference Power level is automatically set to a point more or less centered in time between the 3 dB 

points on the pulse. The power axis of the display is also adjusted so that the point selected as the 

reference point is set to the top of the display as 100%. 

The second method is to allow you to set the Reference Power at some desired level. Power 

measurements can be taken at different points along the top of the pulse to find the optimum point at 

which to set the Reference Power. These decisions are based on the types of pulses it is expected will be 

encountered. 




Reference Power Related Commands 

PRFAsnn.nn 

PRFBsnn.nn 

Set Channel A Reference Power for graphic display. Sets 100% power reference 

point as a reference for automatic timing measurements. It also serves to center the 

pulse on the power axis so that displays and plots of pulses with low amplitudes are 

expanded to show more resolution. 

(s = polarity; nn.nn = dBm value) 

Set Channel B Reference Power for graphic display. Sets the 100% power reference 

point as a reference for automatic timing measurements. It also serves to center the 

pulse on the power axis so that displays and plots of pulses with low amplitudes are 

expanded to show more resolution. 

(s = polarity; nn.nn = dBm value) 

Min Value: -60.00 dBm, Max Value: +110.00 dBm 


10 P=0 ! CHANNEL A REFERENCE 

20 ! POWER IN DBM 

30 ! 

40 ! CHANGE CHANNEL A REFERENCE 

50 ! POWER 

60 OUTPUT 704;PRFA;P 

70 ! 

80 ! CHANGE CHANNEL B REFERENCE 

90 ! POWER 

100 OUTPUT 704;PRFB;P 

110 END 

☛ NOTE: RPOA and RPOB are operable only in the Graph Mode. 

RPOA 

Output Current Reference Power for Channel A. If the PPM is in the linear mode it 

will output: 

RFALnn.nnEsnn 

(nn.nn = Watts; Esnn = exponent) 

If the PPM is in the dBm mode it will output: 

RFADsnn.nn 

(nn.nn = dBm; s = polarity) 

RPOB 

Output Current Reference Power for Channel B. Linear mode output is: 

RFBLnn.nnEsnn 

(nn.nn = Watts; Esnn = exponent) 

The dBm mode output is: 

RFBDsnn.nn 

(nn.nn = dBm; s = polarity) 




Automatic Timing Measurement Commands 

When making timing measurements, the delay window should be set so that the time to be measured 

corresponds to at least one third of the total delay. For example, do not use a delay window of 10 µs to 

measure rise times faster than 3 µs; go to a shorter delay window. 

(Note: *RISE, *FALL, *PLWD, *RSFL, and *RSWD are operable only in the Marker Mode) 

*RISE 

Measure and output rise time of the displayed pulse profile. Rise time is from the 

10% power point to the 90% power point on the rising edge of the pulse. Output 

format for channel A is: 

RISAnn.nnnEsnn 

(n = seconds; Esnn = exponent) 

Output format for channel B is: 

RISBnn.nnnEsnn 

*FALL 

Measure and output fall time of the displayed pulse profile. Fall time is from the 

90% power point to the 10% power point on the falling edge of the pulse. Output 


FALAnn.nnnEsnn 



FALBnn.nnnEsnn 

*PLWD 

Measure and output pulse width of the displayed pulse profile. Pulse width is the 

time between the 50% power points on the rising and falling edges of the pulse. 

Output format for channel A is: 

WIDAnn.nnnEsnn 



WIDBnn.nnnEsnn 

*RSFL 

Measure and output rise time and fall time of the displayed pulse profile. For 

definitions, see *RISE and *FALL descriptions. Output format for channel A is: 

RISAnn.nnnEsnn,FALAnn.nnnEsnn 



RISBnn.nnnEsnn,FALBnn.nnnEsnn 




*RSWD 

Measure and output rise time and pulse width of displayed pulse profile. For 

definitions of rise time and pulse width, see *RISE and *PLWD descriptions. Output 


RISAnn.nnnEsnn,WIDAnn.nnnEsnn 



RISBnn.nnnEsnn,WIDBnn.nnnEsnn 

*WDFL 

Measure and output pulse width and fall time of displayed pulse profile. For 

definition of fall time and pulse width, see *FALL and *PLWD descriptions. Output 


WIDAnn.nnnEsnn,FALAnn.nnnEsnn 



WIDBnn.nnnEsnn,FALBnn.nnnEsnn 

3.3.7 Manual Marker Placement/Timing Measurement Commands 

The PPM has a very forgiving command syntax. It is possible to send many commands in one string. For 

example, it is possible to use one string to place four different markers and then have the PPM output 

two pairs of delay differences. 

Due to the upgrading of the software functions in the 8500A instruments, some of the commands shown 

in this section will not be required when new code is written for the 8501A/8502A meters. The 

commands are retained in this manual for users with programs written for older 8500 instruments, and 

who want to cross-reference for the new 8500A instruments. If old code has been written for an 8500 

instrument and includes some of these commands, the program will still operate with the 8500A but the 

commands will have no function. The term No Op is used in the descriptions for these commands. The 

commands that fall into this category will be defined. 

The MRKA (or B) command must always be executed before any other marker bus commands will be 

accepted. 

MKPRn,xx.x 

Place Marker n (1 to 4) on the rising edge of the pulse at the % reference power defined by xx.x, and 

output the delay. The specified % reference must be between 0.1% and 99.9%. If channel A is in use, the 

PPM will output: 

MRKAm,snn.nnnEsnn 

If channel B is in use, the PPM will output: 

MRKBm,snn.nnnEsnn 

(m = marker number; s = polarity; nn.nnn = delay in seconds; Esnn = exponent) 

MKPFm,xx.x 

Place marker n (1 to 4) on the falling edge of the pulse at the reference power defined by xx.x, and 

output the delay. The specified reference power must be between 0.1% and 99.9%. If channel A is in use, 

the PPM will output: 




MRKAm,snn.nnnEsnn 

For channel B, the output is: 

MRKBm,snn.nnnEsnn 

(m = marker number; s = polarity; nn.nnn = delay in seconds; Esnn = exponent) 

Because markers are always placed in the 8500A, the MKDF and MKPA commands described next will 

take only the latest computation and send it over the bus if they are included in the command string for 

the 8500A. The MKDF-1 command is a No Op command because markers are always placed. 

MKDFm,n 

Place marker numbers m and n according to their previously defined % reference powers and positions on 

the pulse profile, and output the difference between their respective delays. If channel A is in use, the 

PPM will output:MDFA,m-n,nn.nnnEsnn. 

If -1 is the argument for MKDF, markers m and n must have been previously defined for automatic 

placement. Otherwise the default settings will be used. The defaults are: 

• M1 = 2.5% 

• M2 = 17.8% 

• M3 = 46.9% 

• M4 = 90% 

If channel B is in use, the PPM will output: 

MDFB,m-n,nn.nnnEsnn 

(m = first marker number defined; 

n = second marker number defined; 

nn.nnn = the delay of m minus n in seconds; 

Esnn = exponent) 

MKPA 

Place all four markers according to their previously defined % reference powers and 

positions on the pulse profile and output their respective delays. For channel A, the 

output is: 

MRKA1,snnn.nnEsnn;2,snnn.nnEsnn;3,snnn.nn Esnn;4,snnn.nnEsnn 

If channel B is in use, the output is: 

MRKB1,snnn.nnEsnn;2,snnn.nnEsnn;3,snnn.nn Esnn;4,snnn.nnEsnn 

The numbers 1, 2, 3 & 4 represent the marker numbers to be used. The snn.nnEsnn following each 

marker number is the delay time of that marker with respect to the reference delay. 

(s = polarity; nnn.nn = delay in seconds; Esnn = exponent.) 

The arguments between each set of marker information are separated by a semi-colon. 

If a marker number cannot be used for some reason or if the PPM could not place the marker, an SRQ 

will be generated and the marker will not be placed. Then the instrument will output a delay of 0.00 

00E-99 seconds for that marker. If all markers are placed successfully, a service request will be generated 

and the status condition will be 31. If one or more markers are not placed for the reasons described 

above, then the status condition will be 37 after SRQ. 

Since markers are set at percentages of reference power and then the delay is computed by the 8500A 

instruments, the MKDA and MKDB commands described next are classed as No Op with the 8500A 

instruments. 




MKDAm,snnnnnn.nn 

Set Marker Number m to Desired Delay, n, in microseconds on Channel A. (200,000 microseconds 

maximum) 

MKDBm,snnnnnn.nn 

Set Marker Number m to Desired Delay, n, in microseconds on Channel B. (200,000 microseconds 

maximum) 

Since marker information is constantly being updated in the 8500A, the MKCA and MKCB commands 

described below are No Op with the 8500A instruments. 

MKCAm Clear Marker Number m on Channel A. 

MKCBm Clear Marker Number m on Channel B. 

The preceding two commands clear both the current marker delay and any definition of automatic marker 

placement. In other words, they define the marker not to be placed. 

3.3.8 Window and Cursor Control Commands 

Some commands can be used in the Graph Mode as well as the Peak Mode of operation. Peak power 

measurements are made by placing the Cursor at the desired time point on the pulse to be measured. The 

Cursor Delay is with respect to the Reference Delay. Therefore, in the Peak Mode of operation, it is 

possible to set the Reference Delay and the Cursor Delay. These two commands are repeated here for use 

in the Graph Mode of operation. 

Reference Delay is primarily used only in situations where you want to pick an arbitrary point on the 

pulse as the reference to which all other timing measurements are to be made. One example might consist 

of a gaussian shaped TACAN radar pulse that is slightly distorted. You might want to make timing 

measurements with respect to the highest point on the pulse. You might also want to know the timing of 

the 3 dB point of the pulse with respect to its peak. When in doubt, the Reference Delay should be set to 

0.0000 nanoseconds. 

Besides the Reference Delay and Cursor Delay, the Start Delay and Window Delay can also be controlled. 

When the Reference Delay is 0, the Start Delay is the time between the occurrence of a trigger and the 

beginning of the display of information on the PPM’s graphic display. The Window Delay is the time 

window shown on the PPM display. By expanding or contracting the window, it is possible to view a 

wider or narrower pulse as desired. If Autoscaling is used, the PPM makes these settings automatically. 

RDLAnnnnnn.nn 

Set Channel A Reference Delay. This is an arbitrary reference point for referencing 

other timing measurements. 

Min. Value: 0 µs, Max. Value: 213999.97 µs 

(n=microseconds) 

RDLBnnnnnn.nn 

Set channel B Reference Delay. This is an arbitrary reference point for referencing 

other timing measurements. 

Min. Value: 0 µs, Max. Value: 213999.97 µs 

(n = microseconds) 

CDLAsnnnnnn.nn 

Set Cursor Delay for Channel A. Sets the timing position of the Cursor on the 

graphic display, or for Peak measurements. The Cursor is the vertical line on the 

display where the power reading (CSR PWR) is taken. (Timing is relative to the 

Reference Delay.) 





Min. Value: 0 - Reference Delay, Max. Value: 213999.97 µs - Reference Delay 

CDLBsnnnnnn.nn 

CDOA 

Set Cursor Delay for Channel B. Sets the timing position of the Cursor on the 

graphic display, or for Peak measurements. The Cursor is the vertical line on the 

display located where the power reading (CSR PWR) is taken. (Timing is relative to 

the Reference Delay.) 


Min. Value: 0 - Reference Delay, Max. Value: 213999.97 µs - Reference Delay 

Output Current Channel A Cursor Delay. The PPM will output: 

CDLAsnn.nnnEsnn 

(s = polarity; nn.nnn = delay in seconds; Esnn = exponent) 

CDOB 

Output Current Channel B Cursor Delay. The PPM will output: 

CDLBsnn.nnnEsnn 

(s = polarity; nn.nnn = delay in seconds; Esnn = exponent) 

SDLAsnnnnnn.nn 

SDLBsnnnnnn.nn 

WDLAnnnnnn.nn 

WDLBnnnnnn.nn 

Start Delay for Channel A. Sets timing position of left side of graphic display. 

Timing is relative to the Reference Delay. 


Min. Value: 0 - Reference Delay, Max. Value: 213999.97 µs - Window Delay - 

Reference Delay 

Start Delay for Channel B. Sets timing position of left hand side of graphic display. 

Timing is relative to the Reference Delay. 


Min. Value: 0 - Reference Delay, Max. Value: 213999.97 µs - Window Delay - 

Reference Delay 

Delay Window for Channel A. Sets the amount of time from the left side to the right 

side of the graphic display. 

Delay Window for Channel B. Sets the amount of time from the left to the right side 

of the graphic display. 

(n = microseconds; s = exponent) 

Min. Value: 12 ns, Max. Value: 213999.97 µs - Start Delay - Reference Delay 




3.3.9 Commands to Output Graphic Data to a Controller 

The PPM can be programmed to output data in several ways as described in Section 3.2.5. When working 

with graphic displays it may be useful to enter the entire pulse profile into the controller. Once data has 

arrived at the controller, various programmed operations can be conducted. For example, you can 

program the controller to calculate the peak-to-peak pulse flatness. The advantage of this method of data 

acquisition is that it is not necessary to go through the procedure of placing the cursor, taking a power 

reading, and then repeating the procedure until all points of interest are entered into the controller. 

The PPM graphic display dump capability allows the controller to use one command to fetch 118 data 

points along the pulse profile, as well as any pertinent timing settings relating to the profile being 

examined. 

DUMG 

Output All 118 Power Measurement Points of the Displayed Pulse Profile. If Channel A is in use, 

the PPM will output: 

RDLAnn.nnnEsnn, 

SDLAnn.nnnEsnn, 

WDLAnn.nnnEsnn, 

PWRAnnn.nnEsnn,nnn.nnEsnn, (repeats until all 118 data points have been output) 

(Esnn = exponent) 

The PPM outputs the Reference Delay (RDLA) in seconds (nn.nnn), then the Start Delay (SDLA), and 

then the Window Delay (WDLA). This information is followed by the 118 power readings representing 

the pulse profile. All fields and data points are separated by commas. The header for the power readings 

is PWRA. The power readings take the form of nnn.nnEsnn; where nnn.nn is always in Watts, and Esnn 

is the exponent. 

When the PPM outputs using Channel B, the headers change to indicate B channel: 

RDLB 

WDLB 

SDLB 

PWRB 




3.3.10 Plotting Commands 

As previously mentioned, there is very little reason to plot or conduct graphic operations in the Graph 

Mode. All of the operations conducted through the GPIB can be accomplished in the Marker Mode. (This 

is not completely true in the manual mode of operation.) Therefore, it is assumed that the PPM is in the 

Marker Mode of operation when executing any of the commands listed in this section for making 

hardcopy plots. 

As described in the Stand Alone Plot Output Mode description, the PPM has two different plotting 

modes. The Stand Alone Plot mode should not be used when the instrument is under the control of a 

remote controller. Also, the Stand Alone Plot mode should not be initiated from the front panel of the 

PPM when the instrument is under GPIB control. 

☛ NOTE: For proper system operation, make sure that no active controller is on the bus when 

the front panel function is initiated. 

Before a plot is made, you might want to enter a part number or code number that can be used for 

reference. These commands are summarized in the following description. 

PLCNaaaaaaaaaaaa 

Set Code Number for plot to ASCII string represented by up to 12 characters (a). 

PLPNbbbbbbbbbbbb 

Set Part Number for plot to ASCII string represented by up to 12 characters (b). 

PLOT 

Plot pulse profile currently displayed. Marker information will be plotted if the PPM 

is in the marker sub-mode. Pulse information will be plotted if the PPM is in the 

pulse sub-mode. 

There is also a sample program in Section 3.2.5 showing how to format the required 

listen and talk addressing procedures. 

PLTT 

PLTM 

PTTM 

This is the same as the PLOT command, but at a slower speed for transparency plots. 

Change to Marker sub-mode, and then Plot. 

Same as PLTM, but at a slower speed for transparency plots. 

☛ NOTE: If you want to save a plot on disk exactly as it would have been plotted by a digital 

plotter, the entire HPGL plot string can be entered into a variable in the GPIB controller 

using the following program: 

10 DIM A$(CCCCC) ! NEED VARIABLE SIZE 

20 ! HERE 

30 OUTPUT 704;PLOT 

40 ENTER 704;A$ ! ENTER PLOT HPGL 

50 ! COMMANDS. 

60 ! ADD PROGRAM LINES HERE TO 

70 ! STORE A$ 

• 

• 

100 END 

A$ can be recalled later from the disk file for plotting. 




When plots are output from the PPM, the pulse profile will always be in a linear format including when 

the reference power is labeled in dBm. 

3.3.11 Programming Notes 

The programming commands for the PPM can be strung together as long as the maximum length 

limitations specified in the General Information discussion are not exceeded. 

This feature enables procedures to be formatted in a logical manner, and reduces the overall number of 

programming lines required. The following sample program shows how this can be done. 

10 CLEAR 704! DEVICE CLEAR 

20 OUTPUT 704;ASDL200,AVAS25,AUTO 

30 OUTPUT 704;PLCNabcdefg;PLPNqwerty; 

40 RSFL,PLTM 

50 SEND 7;UNL 

60 SEND 7;LISTEN 6 

70 SEND 7;TALK 4 

80 SEND 7;DATA 

90 WAIT 180 

100 SEND 7;UNT UNL 

110 END 

Line 20: Sets the maximum pulse width for autoscaling to 200 microseconds; sets the averaging for 

autoscaling to 25 averages; instructs the PPM to autoscale. 

Lines 30 & 40: Set the code numbers for the plot to abcdefg; sets the part number for the plot to qwerty; 

instructs the PPM to find the rise and fall times of the displayed pulse; instructs the PPM to place the 

markers as defined and to plot the displayed pulse profile. 

The remaining lines in the sample program are used for bus handling. 

Care should be exercised when grouping commands. If conflicting commands are sent in the same string, 

the last one to be received will be implemented. For example: 

OUTPUT 704;MRKA,CDLA5,PKPA 

This program line would result in the cursor delay being set at 5 µs, but the PPM would enter the 

channel A Peak Mode, not the Marker Mode as indicated by the MRKA portion. In other words, the PPM 

does not execute any of the commands until (CR) (LF) are received at the end of the program line. 




3.4 Service Requests and Serial Poll 

The ability of the PPM to request service over the GPIB can be enabled or disabled by a GPIB command. 

The PPM’s power-on default status enables the SRQ function of the instrument. Usually a service request 

is generated to report a significant condition to the controller, and the status byte will not be cleared until 

it is read; REN is disasserted; or the instrument is reset. The exception to this is the output-ready 

condition which will also be cleared when the data is read. If SRQ is disabled the status bytes are not 

saved, but the current condition is available to be read using the STAT command. 

All SRQs are buffered in the PPM. If another error condition is detected after the first value has been 

read, then the SRQ will remain asserted with the second value in the status byte. Up to 16 status 

conditions can be buffered in this way. Once a non-zero condition is read from the PPM, the status byte 

should be read until it becomes zero by taking appropriate action. For example, if the error were 

over-range power, over-range SRQs will continue until the error is fixed. 

When the controller reads the status byte through the GPIB via a serial poll, the 7th bit will always be 

high if the PPM was requesting service. Thus, the actual value of the PPM status will be the byte that is 

read minus the 7th bit. When the PPM’s status is read by the STAT command (when SRQ is disabled), 

the byte that is sent out always has the 7th bit as zero (see 3.2.5). Any status condition that has the sixth 

bit high will indicate abnormal device operation. In decimal form, this is the case for any status code of 

value greater than or equal to 32. 


10 ! THIS PROGRAM USES SERIAL POLL 

20 ! AND SRQ TO DETERMINE IF THE 

30 ! PPM SUCCESSFULLY AUTOSCALED 

40 ! AS INSTRUCTED. 

50 ! 

60 A=0 

70 ! ENABLE GPIB INTERRUPT 

80 ON INTR 7 GOSUB 180 

90 ENABLE INTR 7;2 

100 ! 

110 ! ENABLE PPM SRQ 

120 OUTPUT 704;SRQE 

130 ! INSTRUCT PPM TO AUTOSCALE 

140 OUTPUT 704;AUTO 

150 ! 

160 ! SRQ WAIT LOOP 

170 GOTO 160 

180 ! SRQ HANDLING ROUTINE: 

190 ! CONDUCT SERIAL POLL, AND 

200 ! PUT STATUS BYTE VALUE IN 

210 ! VARIABLE A 

220 A=SPOLL(704) 

230 ! SUBTRACT 64 FROM STATUS 

240 ! BYTE TO GET STATUS CODE 

250 ! NUMBER CORRECT. AUTOSCALING 

260 ! RETURNS A CODE OF 27. 

270 ! 

280 A=A-64 

290 IF A=27 THEN GOTO 330 

300 DISP AUTOSCALING PROBLEM 

310 GOTO 340 

320 RETURN 

330 DISP AUTOSCALING OK 

340 BEEP 

350 END 




3.4.1 Error Conditions 

When it is first activated, the PPM will check to see if there has been a change in its internal software. 

An SRQ will be sent over the bus if any change is detected. The PPM will attempt to capture the PROM 

data from the detector(s), and will also check the detector’s serial number(s) to see if there has been a 

detector change. The instrument will also detect a change in detectors that occurs at any time during a 

test and measurement operation. When detectors are changed, the instrument will request service and 

calibration will be required. No data can be taken over the GPIB until recalibration has been completed, 

or the detector has been removed or changed for the detector that was last calibrated. 

If the instrument detects a power over range condition, it will send an SRQ. If data is being collected to 

be output over the bus, the data will still be available in memory and can be read out. However, if the 

power level was outside the PPM’s normal range the data may not be accurate. This data may still give 

some idea of what power was being measured. If a serious over-range condition occurred, detector 

damage may have resulted. 

If an under-range condition occurs when the PPM is operating under bus control and it is not collecting 

data to be sent over the bus in the Update Data Trigger Reset, or Update Data Continuously Modes, then 

the instrument will not signal the controller (with a service request) that the under range condition has 

occurred. Instead, the data display will display the standard under range message of ———. However, if 

the instrument is collecting data to send over the bus and the data is under range, then the PPM will 

request service (if SRQ is enabled) to report the condition if you asked for it to be reported. If the 

instrument is in the Update Data Trigger Reset Mode, the under range condition will be reported (via a 

serial poll) before the output ready condition. The data that will be output over the bus, if the data is still 

requested, will be an impossible value to indicate to the controller that an under range condition has 

occurred and that the data is not valid. If the log (dBm) mode were in use, the instrument would output a 

reading of -999.99 dBm. In the linear mode, the reading will be 000.00E-99. 




3.5 1018B Emulation 

Emulation of the 1018B instrument is accessed through the front panel. 

The differences in the 1018B emulation mode to standard 8501A/8502A PPM operation are as follows: 

Commands 

The command set is limited to the three following 1018B commands: 

Command 

Argument 

? Update data, behaves exactly as the UPDN PPM command 

< nnn Sets cursor delay to a value between 0 and 9.99 µs 

> nnn Sets cursor delay to a value between 0 and 99.9 µs 

One to three digits are required, no sign or decimal point is allowed. 

The instrument will only read the first 1018B command it receives and ignore the balance of any 

command string it receives. If the string does not start with a valid 1018B command, the instrument will 

ignore the entire string and take no action. 

Output Data Modes 

There are two output data modes in the 1018B Emulation Mode. These are Update Data Trigger Reset 

and Update Data Continuously. The default state upon entering the 1018B Emulation Mode is Update 

Trigger Reset. After that, the output mode can be changed from the front panel (see the Front Panel 

Menus description Section 3.2.2). The two modes work in exactly the same way as with the PPM except 

that the data output format is different. 

Output Format 

The data will always be output in a string consisting of a polarity sign, four digits, a comma, one last 

digit with a value of 0 - 3, a carriage return, and then a line feed character (all data lines low) sent with 

EOI. The first four digits represent the measurement, and the last digit after the comma indicates the 

range. 

Range 

Data Format 

0 snnn.n dBm 

1 snnn.n microwatts 

2 snn.nnn milliwatts 

3 sn.nnn milliwatts 

☛ NOTE: The sign will always be positive for linear values. 

Examples: 

-0147.0(CR)(LF)(NULL - EOI) = -14.7 dBm 

+1257.3(CR)(LF)(NULL - EOI) = +1.257 mW 

In the Update Continuously Mode, a continuous string of these measurements will be sent, including the 

terminating characters, until the PPM is untalked. 




Remote State 

As in the regular PPM operation mode, the instrument must be in the REMOTE state to accept any 

commands over the GPIB or to output any data. However, unlike the standard PPM operation, the front 

panel is fully active while in the REMOTE state and more Menu options will become active in 1018B 

emulation (see the Front Panel Menus discussion in this section). This imposes two requirements for the 

operator. One is the fact that a cursor delay will be accepted on either the front panel or over the GPIB. 

The most recent cursor delay will determine the measurement. The other difficulty is that a measurement 

and not a menu prompt must be displayed on the screen for the instrument to be able to collect data. If 

the controller tries to collect data while the PPM has a front panel menu displayed, the PPM will take no 

action until it returns to displaying data on the front panel. Then it will collect and output the data. Also, 

there is no return to local escape sequence while in REMOTE since the front panel is not locked out. 

There is no local lockout feature either. 

Serial Poll 

The serial poll feature operates similar to the 1018B serial poll function. The only time SRQ is asserted 

is if an output is ready and the value of the status byte is zero. 

Front Panel Menus 

The front panel menu will include three options regarding GPIB control when in the 1018B emulation 

mode. These options represent capabilities which can be set on the 1018B front panel, but not on the 

PPM in general usage. This is because each of these options are directly controllable over the GPIB in 

normal PPM usage. 

Disable/Enable SRQ: 

Update on Trigger 

Reset/Continuous: 

End 1018B 

Emulation Mode: 

This allows the SRQ capability to be enabled or disabled with the same effects 

as the SRQE and SRQD PPM GPIB commands. Whatever option is offered, 

enable or disable, will be the opposite of the current state. 

This sets the Output Mode. The choice offered will be the opposite of the 

current mode. Upon entering the 1018B emulation mode, the Output Mode 

will be set to Update on Trigger Reset. 

This prompt will replace the menu prompt that initiated the 1018B Emulation 

Mode. 

Analog Output 

When using the PPM in the 1018B Emulation Mode, it should be kept in mind that the 1018B instrument 

has a 10 mV/dB Analog Output while the PPM has 100 mV/dB. If the 10 mV/dB output of the 1018B is 

required, a 10:1 resistive L attenuator can be placed on the PPM’s output. 

Two Detectors 

The Model 8502A has two detectors instead of only one as does the 1018B. When in the 1018B 

Emulation Mode, either detector can be used with the choice made through the front panel. It is up to the 

operator to know which detector is active when the command is given over the GPIB to change cursor 

delay or to take a measurement. If both detectors are active, the instrument will ignore any GPIB 

commands and not be able to output any data. 

Reference Delay, Correction of Carrier Frequency, and Offset vs 1018B Direct Mode 

A correction will always be made on the carrier frequency. However, to simulate the 1018B direct mode 

if desired, the reference delay and offset features of the PPM can be negated by setting both to zero via 

the front panel. 




Over and Under Range Conditions 

The maximum value that the 1018B can output is 19.99 mW. Any power reading over that will just result 

in a reading of 19.99 mW when in the linear mode. In the log mode, the reading could be displayed up to 

099.99 dBm. The minimum values are 000.0 µW in the linear mode or a reading of -099.9 dBm 

indicating an under range condition in the log mode. 

1018B Features Not Emulated by the PPM 

Following is a list of the differences in GPIB operation when the Model 1018B Peak Power Meter is 

replaced on the bus with a Model 8501A or Model 8502A Peak Power Meter (PPM): 

1. The PPM has no ability to be directly triggered with a GET command. It can only reset its 

trigger to capture the next pulse that will trigger the instrument. 

2. The PPM has no talk only mode. 

3. Whereas the 1018B allowed completely independent talk and listen addresses, the PPM must 

have the same talk and listen addresses. The addresses are set as one via the front panel. 

4. The 1018B locks out the front panel delay setting capability while in the REMOTE state. The 

front panel delay setting ability remains active on the PPM when in the REMOTE state of the 

1018B Emulation Mode. 

5. The 1018B will take commands and output data even if it is not in the REMOTE state. This 

requires the instrument to be in REM. 




3.6 Status Code Decimal Values 

The decimal values of the various status codes minus the 7th bit are as listed below. 

To determine the value with the 7th bit high, add 64 to the values listed in Table 3-1. 

Table 3-1. Status Code Values and Conditions 

Decimal 

Value 

Condition 

0 Operation normal, no condition to report 

1 Output ready to be sent over GPIB 

10 Self test passed 

20 Calibration passed 

25 Autozero passed 

27 Autoscaling completed and passed 

31 If RISE, PLWD, FALL, RSFL, RSWD, WDFL, PUFT, PURT, OR PUWD all measurements 

successfully made 

33 Command string syntax error, command(s) not processed 

34 Command string has invalid argument, command(s) not processed 

35 Command string(s) incomplete when unlistened, string(s) sent so far are lost, command(s) not 

processed 

36 PPM command buffer overflow. Limit of 128 character string exceeded. String lost, no 

commands processed 

37 Cannot execute MKDF, markers to be measured are undefined. No command(s) processed 

38 Command not executed, PPM not in REMOTE state 

39 Command not implemented, no commands processed 

40 GET sent when not in REMOTE 

41 GET or UPDN command sent when not in the Update Data Trigger Reset Output Mode. If 

UPDN command, no command(s) processed 

43 Not in Graph Mode or Marker sub-mode, must be in Graph Mode for AUTO (Autoscale 

Graph), or PLOT commands to function. Must be in Marker sub-mode for marker commands 

to function. No command(s) processed 

44 Autoscaling, PLOT, DUMG, pulse parameter, or a marker placement command has been 

specified in the command string and a mode change requested later at some point in the same 

command string. Mode change not processed 

45 STAT command sent while SRQ enabled, STAT command not active 

46 SRQ buffer overflow, SRQ enabled and not being read quickly enough by the controller 

48 Cannot enter Fast Measurement Mode. Either in linear, graph, or marker mode. No 

command(s) processed 

49 Cannot execute RECL or WATT commands, or any graph or marker commands in the Fast 

Measurement Mode. No command(s) processed 

50 Error in reading PROM data from detector A 

51 Error in reading PROM data from detector B 




Decimal 

Value 

Condition 

52 Calibration aborted for lack of a detector 

53 Calibration passed, but with PROM read error 

54 Calibration failed with PROM read error 

55 Calibration failed 

57 Autozero aborted for lack of detector 

58 Autozero fail 

59 Autoscaling aborted for lack of detector 

60 Autoscaling interrupted by GPIB bus command, no trigger received 

61 Unable to Autoscale 

63 Unable to place markers specified or required to make a pulse parameter measurement 

170 Self test failed 

See Self-Test Failure Indications in Section 3.6 for a description and possible causes pertaining to Error Numbers 01 

through 11. These will be decimal values 170 through 180, respectively 

184 New software detected. Must recalibrate both detectors 

185 Serial numbers don’t match. Must recalibrate A and B detectors. 

186 Serial number doesn’t match. Must recalibrate detector A 

187 Serial number doesn’t match. Must recalibrate detector B 

189 Instrument operation failure. PPM will probably need to be reset 

190 Under range. Measurement not accurate 

191 Over range. Damage to instrument may have occurred 




3.7 Summary of Bus Functions 

3.7.1 Normal PPM Operation 

The bus functions for normal PPM operation (under GPIB control) are defined in Table 3-2: 

Table 3-2. Summary of Bus Functions 

Code 

SH1 

AH1 

T6 

TE0 

L4 

LE0 

SR1 

RL1 

PP0 

DC1 

DT1 

C0 

Complete source handshake capability 

Complete acceptor handshake capability 

Function 

Basic talker and serial poll capability, unaddressed as a talker if listen addressed, no talk only 

mode 

No talk-address extension capability 

Basic listener capability; unaddressed as a listener if talk-addressed — no listen-only mode 

No listen-address extension capability 

Complete service request capability (when SRQ enabled) 

Complete remote local interface capability with local lockout capability 

No parallel poll capability 

Complete device clear capability [responds to device clear (DCL) and selective device clear 

(SDC)] 

Complete device trigger capability [responds to group execute trigger (GET)] 

No controller capability 

3.7.2 PPM Stand Alone Plot Operation 

When the PPM is in the Stand Alone Plot mode, two functions will exhibit different capabilities. The 

Talker and Controller functions are redefined as follows: 

T5: Same as T6 capability except it has talk-only capability while plotting. 

C1, C3, & C28: System controller capability with the ability to send REN and interface messages, but 

with no capability to send IFC, respond to SRQ, conduct parallel poll, or pass control. 




3.8 GPIB Command Summary 

A summary of the GPIB commands referenced in this chapter are listed alphabetically in Table 3-3. When 

arguments are not required, the argument column is blank. If the command is not intended to make the 

PPM output a data string, the output string will indicate ’none’. Arguments are represented by lowercase 

characters while commands and output string headers (always four characters) are uppercase. The 

position of the decimal point can vary in Delay commands. 

Table 3-3. GPIB Commands Format 

Command 

ACBC 

ACBP 

APBC 

APBP 

ASDLnnnnnn.nn 

AUTO 

AVASnnn 

AVCWnnn 

AVPKnnn 

CALA 

CALB 

CDLAnnnnnn.nn 

CDLBnnnnnn.nn 

CDOA 

Argument 

Select Ratio Mode - Channel A (CW) to Channel B (CW) / none 

Select Ratio Mode - Channel A (CW) to Channel B (Peak) / none 

Select Ratio Mode - Channel A (Peak) to Channel B (CW) / none 

Select Ratio Mode - Channel A (Peak) to Channel B (Peak) / none 

Select Initial Delay Used for Autoscaling Pulse Profile / none 

(n = microseconds; 200,000 maximum) 

Autoscale Current Pulse Profile / none 

Select Averaging Value Used for Autoscaling Pulse Profile / none 

(n = 1 to 999) 

Select Number of Averages for CW Power Measurement / none 

(n = 1 to 999) 

Select Number of Averages for Peak Power Measurement / none 

(n = 1 to 999) 

Calibrate Channel A Detector. Takes time to complete - SRQ can monitor successful 

(or unsuccessful) completion / none 

Calibrate Channel B Detector. Takes time to complete - SRQ can monitor successful 


Set Channel A Cursor Delay / none 

(n = microseconds; 213,999.97 - Ref Dly maximum; 0 - Ref Dly minimum) Position 

of decimal point may vary. Cursor Delay is in respect to the Reference Delay. If 

Reference Delay = 0, then the Cursor Delay is with respect to the trigger. 

Set Channel B Cursor Delay / none (see CDLA) 

Read Out Current Channel A Cursor Delay / PPM will output: 

CDLAsnn.nnnEsnn 

s = polarity; n = Cursor Delay in seconds (decimal point may shift); Esnn = 

exponent value in engineering notation 

CDOB 

Read Out Current Channel B Cursor Delay / PPM will output: 

CDLBsnn.nnnEsnn 

(see CDOA) 

CWAB 

CWPA 

CWPB 

Select Dual Channel Mode: CW Both Channels / none 

Select Channel A Only: CW Power / none 

Select Channel B Only: CW Power / none 




DATF 

Command 

Argument 

Select Data Fast Operation (No EL Display) / none 

NOTE: Graph, Marker or Linear Power Modes cannot be used while operating in 

DATF. Conversely DATF cannot be used while in the Graph, Marker or Linear Power 

Modes. Do not use commands related to these modes when the DATF function is in 

use. 

DATN 

DBMW 

DCFAc.cc 

DCFBc.cc 

DTMP 

Select Data Normal Operation (Exit Data Fast) / none 

Select dBm Power Format / none 

Select Channel A Cal Factor / none 

(c.cc = Cal Factor; -9.99dB min, +9.99 dB max) 

Select Channel B Cal Factor / none (See DCFA) 

Read Out Temperature Difference of Detectors Since Last Calibration / PPM will 

output: 

DTPAsxx.x, DTPBsyy.y 

DUMG Graphic Display - Read Out Reference Delay, Start Delay, Window Delay, and 118 

Displayed Data Points of Current Pulse Profile / When PPM is displaying channel A, 

it will output: 

RDLAnn.nnnEsnn,SDLAnn.nnnEsnn 

WDLAnn.nnnEsnn,PWRApp.ppEspp,pp.ppEspp..... 

(Ref.Dly, Strt. Dly, Wind Dly, Power - 118 points separated by commas. Delays (n) 

are in seconds; Powers are always in Watts) 

FALL 

Measure and Output Fall Time of Displayed Pulse Profile (90% to 10% on the 

falling edge of the pulse profile). This command erases previously set markers. The 

PPM will output the following string when operating in channel A: 

FALAnn.nnnEsnn 

For channel B: 

FALBnn.nnnEsnn 

(n = seconds; Esnn = exponent; s = polarity) 

FPRVvv.vv,ss.ss,mm 

.mm 

FPVOvv.vv,ss.ss,mm 

.mm 

FQDS 

FQHD 

FREQff.ff 

GRFA 

GRFB 

MAXPsnn.nn 

Select External Frequency Input Mode. Sweeper Connected to Rear Panel Input 

Determines Detector Frequency Response Correction / none 

(v = volts/GHz; 0.1 to 10.00; s = Start Voltage; 0 to 19.00; m = Start Frequency; 0 

to 110.00 GHz) 

Select FPVO mode. i.e. Selects the External Frequency input mode and causes 

output of current operating RF frequency with each power measurement taken while 

using UPDN or UPDC / none 

(see FPRV) 

Enable (Unhide) Frequency Information Display on PPM Front Panel / none 

Disable (Hide) Frequency Information Display on PPM Front Panel / none 

Select Frequency for Detector Frequency Correction / none (f = frequency; 0.01 to 

110.00 GHz) 

Select Graph Mode - Channel A / none 

Select Graph Mode - Channel B / none 

Set Power for Overrange Condition / none 

(s = polarity; n = power in dBm; +21.00 max -10.00 min) 




Command 

Argument 

MINPsnn.nn 

Set Power for Underrange Condition / none 

(s = polarity; n = power in dBm; -15.00 max -50.00 min) 

NOTE: Some of the following marker commands are no longer necessary when 

writing code pertaining to markers for the 8500A instruments. See Section 3.3.7 

MKCAn (No Op command with the 8500A) 

Clear Marker Number Selected on Channel A / none 

(n = marker number to clear; 1 to 4) 

MKCBn (No Op with the 8500A) 

Clear Marker Number Selected on Channel B / none 

(n = marker number to clear; 1 to 4) 

MKDAn,dddddd.dd 

MKDBn,dddddd.dd 

MKDFa,b 

(No Op with the 8500A) Select Channel A Marker Delay number n and set the delay 

to d / none 

(n = marker number to clear; 1 to 4; d = marker delay in microseconds; 200,000 

max) 

(No Op with the 8500A) Select Channel B Marker Delay number n and set the delay 

to d / none (See MKDA) 

Place Markers (a and b) which were previously selected and Output Their Delay 

Difference (a - b) Marker differences can also be de-selected - See MKDF-1 / When 

the PPM is in channel A it will output: 

MDFA,a-b,nn.nnnEsnn 

(a = first marker; b = second marker; result will be the marker a delay minus the 

marker b delay) 

MKDF-1 

MKPA 

(No Op with the 8500A) Deselect all Marker Difference Pairs / none 

Autoplace All Four Markers as previously selected and Output Their Delays / If the 

PPM is in Channel A it will output: 

MRKA1,nn.nnnEsnn;2,nn.nnnEsnn;3,nn.nnnEsnn;4,nn.nnnEsnn 

If the PPM is in channel B it will output the same as above only with MRKB header. 

(1, 2, 3 and 4 = marker numbers; n = delay in seconds; Esnn = exponent) 

MKPFa,xx.x 

Place Given Marker on Falling Slope of Pulse Profile at the Selected % Power 

Reference and Output Its Delay / When the PPM is in channel A it will output: 

MRKAa,nn.nnnEsnn 

When the PPM is in channel B it will output: 

MRKBa,nn.nnnEsnn 

(a = marker number; 1 to 4; x = percent of reference power to place marker; 0.1% 

min 99.9% max; n = delay in seconds; Esnn = exponent) 

MKPRa,xx.x 

Place Given Marker on Rising Slope of Pulse Profile at the Selected % Power 

Reference and Output Its Delay / When in channel A the PPM will output: 

MRKAa,nn.nnnEsnn 

When in channel B the PPM will output: 

MRKBa,nn.nnnEsnn 

(See MKPF) 

MRKA 

MRKB 

Select Channel A Marker Sub-Mode / none 

Select Channel B Marker Sub-Mode / none 




Command 

OFFAsnn.nn 

OFFBsnn.nn 

PKAB 

PKPA 

PKPB 

PLCNx 

PLOT 

PLPNx 

PLTM 

PLTT 

PLWD 

Argument 

Set Channel A Offset / none 

(s = polarity; n = dB offset; -40.00 min +90.00 max) 

Set Channel B Offset / none (See OFFA) 

Select Dual Channel Mode: Peak Power Both Channels / none 

Select Channel A Only: Peak Power Mode / none 

Select Channel B Only: Peak Power Mode / none 

Set Code Number to be Plotted / none 

(x = ASCII string of 12 characters or less) 

Plot Pulse Profile Currently Displayed GPIB interface must be managed correctly. 

PPM will output pulse profiles with relevant marker information (or without if 

desired) using HPGL graphics codes to a compatible digital plotter. See Plot Output 

Mode in Section 3.2.5 for plotting instructions. 

Set Part Number to be Plotted / none 

(x = ASCII string of 12 characters or less) 

Change to Marker Sub-Mode and immediately begin plotting / See PLOT 

(This command ensures that the placement of markers is based on the same power 

measurement data as is sent to the plotter for increased accuracy of marker 

placement on the hardcopy plot.) 

Plot Pulse Profile Currently Displayed at Slower Speed for Transparencies / Same as 

PLOT but slower pen speed. 

Measure and Output Pulse Width of Pulse Profile Currently Displayed (50% point on 

rising edge of pulse to 50% point on the falling edge of the pulse). This command 

erases previously set markers / The PPM will output the following string when 

operating in channel A: 

WIDAnn.nnnEsnn 


WIDBnn.nnnEsnn 

PRFAsnn.nn 

PRFBsnn.nn 

PTTM 

PUFE 

PUFS 

PUFT 

Set Channel A Reference Power for Graphic Display / none 

(s = polarity; n = dBm value; +110.00 max -60.00 min) 

Set Channel B Reference Power for Graphic Display 

(s = polarity; n = dBm value; +110.00 max -60.00 min) 

Change to Marker Sub-Mode and plot at Slower Speed for Transparencies / Same as 

PLTT but with slower pen speed. 

Set Pulse Fall Time - End % / none 

[n = % expressed in 0.1% units; 1 to 999 (0.1% to 99.9%)] 

Set Pulse Fall Time - Start % / none 


Measure and output fall time of the pulse profile displayed in the Pulse Parameters 

sub-mode. / The PPM will output the following string when operating in Channel A: 

FALAnnnnn.nEsnn 

For Channel B: 

FALBnnnnn.nEsnn 


PULA 

Select Channel A only: Pulse Parameter submode / none 




Command 

PULB 

PURE 

PURS 

PURT 

Argument 

Select Channel B only: Pulse Parameter submode / none 

Set Pulse Rise Time - End % / none 


Set Pulse Rise Time - Start & / none 


Measure and Output Rise time of Pulse Profile Displayed in the Pulse Parameters 

sub-mode./ The PPM will output the following string when operating in Channel A: 

RISAnnnnn.nEsnn 



RISBnnnnn.nEsnn 


PUWD 

Measure and Output Pulse Width of Pulse Profile Displayed in the Pulse Parameters 

sub-mode. / The PPM will output the following string when operating in Channel A: 

WIDAnnnnn.nEsnn 


WIDBnnnnn.nEsnn 


PUWE 

PUWS 

RDLAnnnnnn.nn 

RDLBnnnnnn.nn 

RECLnn 

Set Pulse Width - End % / none 


Set Pulse Width - Start % / none 


Set Channel A Reference Delay / none 

Set Channel B Reference Delay / none 

(n = microseconds; 213,999.97 max) 

Recall Non-Volatile Set Memory Number n / none 

(n = memory location; 0 to 10; 0 is the last setup before device clear or power off. 

The remainder are user memories in which setups can be stored from the front panel 

or see STOR command) 

RISE 

Measure and Output Rise time of Pulse Profile Currently Displayed (10% to 90% on 

the rising edge of the profile). This command erases previously set markers / The 

PPM will output the following string when operating in channel A: 

RISAnn.nnnEsnn 


RISBnn.nnnEsnn 





RPOA 

Command 

Argument 

Read Out Current Channel A Reference Power / The PPM will output channel A 

reference power in the following format: 

If operating in the Linear Power Mode: 

RFALxx.xxEsnn 

(x = power in Watts; Esnn = exponent) 

If operating in the dBm power format: 

RFADsnnn.nn 

(s = polarity; n = reference power in dBm) 

RPOB 

RSFL 

Read Out Current Channel B Reference Power. (Readout is the same as RPOA, 

substituting B or A) 

Measure and Output Rise and Fall Times of Pulse Profile Currently Displayed. See 

FALL and RISE for definitions used for fall and rise times / When operating in 

channel A the PPM will output: 

RISAnn.nnnEsnn,FALAnn.nnnEsnn 

When operating in channel B: 

RISBnn.nnnEsnn,FALBnn.nnnEsnn 

(n = delay in seconds; Esnn = exponent) 

RSWD 

Measure and Output Rise time and Pulse Width of Pulse Profile Currently Displayed. 

See RISE for definition of rise time. Pulse width is the time between the 50% power 

point on the pulse’s rising edge and the 50% point on it’s falling edge / Channel A 

readout is: 

RISAnn.nnnEsnn,WIDAnn.nnnEsnn 

Channel B readout is: 

RISBnn.nnnEsnn,WIDBnn.nnnEsnn 

SDLAnnnnnn.nn 

Set Channel A Start Delay / none 

SDLBnnnnnn.nn 

SELT 

(n = microseconds; position of decimal may vary. 

Max = 213,999.97 µs - Window Delay - Reference Delay; 

Min = 0 - Reference Delay. 

Start Delay is with respect to the Reference Delay. If Reference Delay is 0 then Start 

Delay is coincident with the trigger.) 

Set Channel B Start Delay / none (see SDLA) 

Initiate Self-Test. Can be used with SRQ for a health check. See Service Requests in 

Section 3.4. 

SRQD SRQ Disable. See Service Requests in Section 3.4 

SRQE SRQ Enable. See Service Requests in Section 3.4 

STAT 

Output Status Byte. This command is only effective when SRQ is disabled. If sent 

while SRQ is enabled an SRQ will be generated. The PPM will output: 

STATnnn 

(n = decimal number representing current Status Byte. See Status Byte Output in 

Section 3.2.5 and Service Requests in Section 3.4) 




Command 

Argument 

STORnn 

TRGAsnn.nn 

TRGBsnn.nn 

TRGE 

Store Current PPM Settings in Non-Volatile Set-Up Memory Number n / none 

(n = number between 1 and 10) 

Select Channel A Internal Trigger and Set Level in dBm / none 

(s = polarity; n = trigger level - +16 dBm max -20 dBm min) 

Select Channel B Internal Trigger and Set Level in dBm / none (See TRGA) 

Select External Trigger Mode / none 

UNDD Disable PPM SRQ for Underrange Conditions. See Service Requests in Section 3.4 / 

none 

UNDE 

UPDC 

Enable PPM SRQ for Underrange Conditions. An SRQ will be generated if the 

power level measurement data is below the level set by MINP / none 

Select Update Data Continuously Output Mode. The PPM will output a continuous 

stream of power measurement data points separated by commas. Every time the PPM 

receives a trigger a new data point is added to the stream. The formats described 

below can occur. 

When using the FREQ, DCFA (A Cal Factor), DCFB (B Cal Factor), or FPRV (Rear 

Panel Frequency Input) methods for detector frequency response correction, the 

PPM’s Linear Mode data output string for channel A will be: 

PWRAnn.nnEsnn,PWRAnn.nnEsnn,PWRAnn.nnEsnn 

(n = linear power in Watts; Esnn = exponent) 

This example shows a data string for 3 triggers. Subsequent triggers will produce 

more data points separated by commas in the form of PWRAnn.nnEsnn. For 

channel B the header before the data points would be PRWB instead of PWRA. 

The PPM’s dBm Mode output for channel A would be: 

DBMAsnnn.nn,DBMAsnnn.nn,DBMAsnnn.nn 


This example shows a data stream for 3 triggers. Subsequent triggers will produce 

more data points separated by commas in the form of DBMAsnn.nn. For channel B 

the header before the data points would be DBMB instead of BDMA. 

When using the FPVO (Rear Panel Frequency Input and Output) method for detector 

frequency response correction, the PPM’s Linear Mode data output string for 

channel A will be in the form: 

PWRAmm.mmEsee,FRQAfff.ffE+09,PWRAnn.nn 

Esee,FRQAggg.ggE+09 

(m = first power data point; 

f = first frequency data point; 

n = second power data point; 

g = second frequency data point; 

Esee = exponent for power in Watts; 

E+09 indicates frequency is in GHz) 

This example shows a data stream for 2 triggers. Subsequent triggers will produce 

more data points separated by commas in the form of 

PWRAnn.nnEsnn,FRQAfff.ffE+09. If the PPM is in channel B the headers before the 

data points would be PWRB and FRQB. See preceding NOTE for description 

of dBm header and data formats. 




Command 

UPDN 

UPDT 

WATT 

WDFL 

Argument 

Update Data Now. i.e: Take a power reading when the next trigger occurs. This 

command is only operational if the PPM is in the Update Trigger Reset Mode. See 

UPDT./ The PPM will output a single data point each time UPDN is received. The 

output formats are the same as those described under UPDC except that each data 

point is not followed by a comma. Instead each point is followed by a carriage 

return followed by a line feed sent with EOI. If FPVO is being used, the frequency 

at which a power measurement was taken is output also. See UPDC and FPVO. 

Select Update Date Trigger Reset Output Mode. Prepares the PPM to take power 

readings using UPDN or GET / none 

Select Linear Power Format / none 

Measure and Output Pulse Width and Fall-times of Pulse Profile Currently 

Displayed. See FALL for definition of fall time. Pulse width is the time between the 

50% point on the pulse’s rising edge and the 50% point on it’s falling edge / When 

operating in channel A the PPM will output: 

WIDAnn.nnnEsnn,FALAnn.nnnEsnn 

For Channel B the output is: 

WIDBnn.nnnEsnn,FALBnn.nnnEsnn 

(n = delay in seconds; Esnn = exponent) 

WDLAnnnnnn.nn 

WDLBnnnnnn.nn 

ZERA 

ZERB 

*IDN? 

Set Channel A Delay Window / none 

(n = microseconds; position of decimal point may vary. 0.012 µs min; 213,999.97 - 

Start Delay - Reference Delay max) 

Set Channel B Delay Window / none 

(See WDLA) 

Autozero Channel A Detector. Takes time to complete - SRQ can monitor successful 


Autozero Channel B Detector. Takes time to complete - SRQ can monitor successful 


Identification Query - Output Model; Software Version. The PPM will output: 

Giga-tronics,8501A,0,VERnn.nn 

8501A = model number; 

0 = N/A; 

VER = software version; 

n = number of the software version. If using a Model 8502A, 8501A would be 

replaced by 8502A 




3.9 1018B Emulation Commands 

1018B Emulation commands will be in the following format: 

Table 3-4. 1018B Emulation Commands Format 

NNN 

Command 

Argument 

Set Delay 0 to 9.99 microseconds (1018B Emulation) / none 

(nnn = delay in hundredths of microseconds) 

NOTE: A decimal point cannot be sent in the argument string. 

Set Delay 0 to 99.9 microseconds (1018B Emulation) / none 

(nnn = delay in tenths of microseconds.) 

NOTE: A decimal point cannot be sent in the argument string. 

? Update Data (1018B Emulation). 

Causes a trigger reset when in the update or trigger modes. The PPM will output 

power measurement data the next time a trigger occurs. 

3.10 Data Formats 

Data will be in the following formats: 

dBm Mode: 

snnnn,0(CR)(LF)(NULL EOI) 

(Interpret snnnn,0 as nnn.n dBm) 

Range 1: (microwatts) 


(Interpret snnnn,1 as nnn.n µW) 

Range 2: (milliwatts) 


(Interpret snnnn,2 as nn.nn mW) 

Range 3: (milliwatts) 


(Interpret snnnn,3 as n.nnn mW) 

(s = polarity; linear always +; n = power value) 

☛ NOTE: When operating in the Linear Mode, the range is determined from the linear range 

that has been set from the front panel. 



4 

Theory of Operation 


This chapter presents a functional description of the electrical assemblies in the Model 8501A and 8502A 

Peak Power Meters (PPM). Table 8-1 in Chapter 8 lists the circuit assemblies by reference designation 

and includes the schematic diagram and assembly number for each board. Schematic diagrams and 

component layouts are in Chapter 8. 

The method to properly ground all PC boards is common throughout the PPM. Each PC board contains 

both input and output isolator stages to transfer the reference or ratio common ground when signals are 

passing between the PC boards to an on-board common ground. When any signals leave the boards, they 

pass through another isolator stage, which transfers them back to the between-the-boards reference 

ground. 

4.2 System Description 

The following is a general description of the PPM circuit, with reference to Figure 4-1. 

The detected RF signal enters the PPM as an analog voltage and is received by the circuits of the Analog 

PC board (A6/A7). The single channel Model 8501A uses only A6 whereas the dual channel 8502A uses 

both A6 and A7. Both boards are identical. 

The Analog board circuits use an RC network to compensate the signal for frequency dependent losses in 

the delay line. The signal is sampled and held until the completion of the data conversion cycle. A/D 

conversion occurs to supply digital data to the Central Processing Unit (CPU). 

The Trigger Amplifier of the Analog board senses the detector output voltage before it reaches the Delay 

Line. It uses the signal to provide an Internal Trigger, controlled and conditioned by the A5 Digital Delay 

board, when the internal trigger is selected. 

The Peripheral Interface circuits interface read and write signals under the control of the CPU board. 

The Analog board also receives temperature information sensed by the thermistor in each detector. 

The programmable delay function of the A5 Digital Delay board establishes the time delays when 

measuring RF pulses. Trigger inputs can come from either the CPU (internal), through the Trigger 

Amplifier, from the pulse itself as it is detected, or from an external source connected to the rear panel of 

the instrument. The Delay board also supplies a synchronized output signal to a rear panel connector for 

an external meter to read the pulse at the point where the sample is taken. 

The A4 CPU board provides (through the CPU Bus Line) the interface between the other PC boards, and 

generates all of the control signals for timing and controlling the various functions of the boards. Apart 

from the bus, the CPU has two other lines from the power supply and the delay board. These inputs tell 

the CPU if there has been a power failure of any kind, and when it should halt its activity until a sample 

of the incoming pulse is taken. This allows the sample to be unaffected by CPU generated interference. 

The A9 Keyboard and A10 Display PC boards interface keystroke and hand wheel movement information, 

and display indication signals to and from the front panel components. These functions are controlled by 

the A8 Front Panel Interface board, which is controlled by the CPU. The front panel interface also has a 




high voltage switching power supply for the Electro-Luminescent (EL) display. The Ready and New Data 

lights on the front panel are turned on and off by control signals sent through A9 from the delay board. 

The A3 GPIB/Cal Control board provides the interface to the GPIB, and contains the circuitry required 

for controlling the operation of the automatic detector Calibrator (A12). It also interfaces with the 

PROMs in the detectors, contains the sound generator circuits, and provides an RF blanking output to 

turn off RF power when zeroing the instrument. 

The A12 Calibrator assembly contains the 1 GHz Programmable Calibration Source that furnishes a 

precise signal for automatic calibration of the PPM detectors. 

MODEL 8502A: 

Channel A shown; 

Channel B is identical 

DETECTOR ASSY 

COMP NET 

A6/A7 

KEYBOARD 

A8 

Delay Line 

RF 

Input 

DETECTOR 

Therm 

SAMPLE/HOLD 

A/D CONVERTER 

A6/A7 

Sample Pulse 

GPIB 

INTERFACE 

A3 

GPIB 

Input/ 

Output 

TRIG AMP 

A6/A7 

Int 

Ext 

PROGRAMMABLE 

DELAY 

A5 

CPU 

PROGRAMMABLE 

INTERFACE 

A6/A7 

A4 

CPU BUS 

DISPLAY 

Trigger 

Input 

A10 (thru A8) 

Calibrator 

1 GHz Output 

1GHz 

PROGRAMMABLE 

CALIBRATION 

SOURCE 

A12 

CALIBRATOR 

CONTROLLER 

A3 

Figure 4-1. Series 8500A System Block Diagram 




4.2.1 Power Supply PC Assembly (A2) 

(See schematic diagram #16996 in Chapter 8. 

The Power Supply PC board generates the +5 Vdc and +15 Vdc power sources required by the 

instrument. Since both voltages are produced in a similar manner, this discussion will cover only the 

+5 V circuitry. 

The +5 Vdc produced on the board is the master voltage regulator for the system. It takes its reference 

from CR21 and compares it with the output voltage between the +5 V Sense and +5 V Common lines. 

Sensing is in the circuit composed of R41, R43, R66, and adjustable at R42. Q7 and Q5 are regulating 

transistors with the regulation voltage available at TP9 for checking. 

-5 V is slaved from the +5 V and regulated through Q9 and Q10. Both the plus and minus voltages are 

compared with ground, and both have current limiting. The +5 V circuit is sensitive to the voltage drop 

across R29, which is controlled in parallel through Q6. U2A is the current limiter for +5 V, and U3A is 

the current limiter for -5 V. U4 compares the unregulated +5 V with the reference from U5. If its output 

is too low, the AC Fail signal will tell the CPU that the power is about to fail. R61, CR19, and C21 will 

keep the voltage supply at U4 up long enough for the +5 V to drop to a logic zero threshold after the 

instrument goes to a power-off state. 

A2 Test Points 

The test points in Table 4-1 can be checked for the correct signals on the A2 Power Supply board: 

Table 4-1. A2 Test Points 

Test Point 

TP1 

TP2 

TP3 

TP4 

TP5 

TP6 

TP7 

TP8 

TP9 

TP10 

TP11 

Description 

Reads the current in the +15 V drive circuitry 

Reads the current in the -15 V drive circuitry 

+15 V 

+15 V Common Sense 

-15 V 

+15 V Common 

Reads the current in the +5 V drive circuitry 

Reads the current in the -5 V drive circuitry 

+5 V Sense 

-5 V Sense 

5 V Common Sense 




4.2.2 GPIB/CAL Control PC board (A3) 

See Figure 4-2 and schematic diagram #21015 in Chapter 8. 

Figure 4-2. GPIB/Cal Control (A3) Block Diagram 

The GPIB/Cal Control PC board circuitry performs a number of functions. The board is the interface to 

the detector PROMs. It contains the sound generator for clicks and beeps as described in Chapter 3, and 

it also has the GPIB interface and calibrator control circuitry. 

With reference to Sheet 1 of DWG# 21015, the GPIB interface is through U1, buffered by U2 and U4. 

U1 performs the proper interfacing between the GPIB and the data and address lines, and the chip select 




and read/write lines. Control signals to activate the sound generator come through U8, which also 

interfaces with the PROMs in each detector. A special 4-bit-wide data bus is connected to each detector, 

and a clock signal common to both detectors sequentially counts the address from 0 to 2048. 

Q1 and Q2 switch on and off the +5 V supply to the channel A detector PROM, and Q3 and Q4 do the 

same for the channel B detector PROM. When the +5 V is switched on, the address counter at the 

detector is reset to zero. 

U8 also has an RF Blanking output signal used during a calibration routine to turn off any input from the 

RF source. The sound generator is controlled by U8 through an amplifier consisting of U11A and Q8, 

with the volume adjustable at R2. U7 is a frequency divider that takes a 3 MHz input and divides it by 

two so that the sound generator gets the 1.5 MHz input it needs for proper operation. 

A major function performed by the GPIB/Cal Control board circuitry is to provide the control signals 

required to operate the automatic RF detector Calibrator. 

With reference to DWG# 21015, Sheet 2, and Figure 4-2, PPI U9 performs several functions. One is the 

control of switches U12A, B, & C and U11B, C & D. These switches are drivers for the pin diode 

switches in the Calibrator, which switch in or out the required attenuation (as shown by the lines on the 

right side of the schematic). Since the three sets of two switches each operate the same, we will look at 

the action of U12A & B. 

When a logic signal is generated from the B0 output of U9, the signal is applied to two inputs of 

opposite polarity (U112A, pin 6, is the minus input and U12B, pin 3, is the plus input). If the logic signal 

is high, this will force pin 7 of U12A to be driven negative and pin 1 of U12B will be driven positive. 

This will turn on the pin diode switch in the Calibrator, which will switch in the desired attenuation (in 

this case, the 10 dB attenuator). If a logic zero comes from the B0 output of U9, then the reverse 

condition will be true and the attenuator will be switched out because current will be forced through the 

attenuator in the opposite direction. 

PPI U9 also interfaces the U10 14-bit DAC with the incoming data bus lines. The interface consists of a 

byte wide data bus from U9 port A, two control lines from U9 ports C0 and C1 to U10 ports A0 and A1, 

and a write enable signal from U9 port C3 to U10 WR. The CS port on U10 is not used. Signals from A0 

and A1 control the operation of U10 so that a write operation can either load the data into the DAC 

internal register’s least significant byte or through DB0 to DB5 to the most significant byte or to transfer 

the register data to the DAC output. 

U13 and U10 work together as a standard inverting operational amplifier. The loaded data connects the 

V REF input through a resistive network to an internal summing junction. The data is also connected to the 

feedback signal from the RFB input through an internal fixed value resistance, and to the inverting input 

of U13. Since V REF has a value of -10 V, the output of U13 pin 6 will range from 0 to 10 V. 

Shown to the lower right of U10 on the schematic is a summing junction which receives one signal from 

U13 through R15, and potentiometer R16 (CALIB SET), which is in parallel with R74. A second signal 

then comes from the thermistor bridge circuit of U16 and Q5. The bridge circuit uses the thermistor in 

the Calibrator as one leg of a bridge. The bridge is self-balancing, and always seeks a voltage level that 

will keep it in balance. When the system is first turned on, the thermistor will have a high resistance 

because it is cold. This unbalanced condition will cause a maximum voltage level to be present at TP9. 

The voltage level will stay high until the thermistor warms up to a point where the bridge is balanced. 

Then the voltage level at TP9 will drop. Due to negative feedback, it will seek a level just sufficient to 

maintain a balance in the bridge. The bridge voltage is fed back into the summing junction through R18. 

The system has two modes of operation controlled by U17A & B which are, in turn, controlled by either 

a high or low output from the B7 connection of U9. In one mode, the circuit measures the voltage of the 

bridge (initiated by a low output from B7); in the other mode of operation, the circuitry controls the 

bridge voltage (initiated by a high output from B7). When it is required to measure the bridge voltage, 

the Calibrator must be turned off so the voltage that selects the measuring mode also turns off the 

oscillator. The reason for this is that the ambient voltage of the bridge must be measured with no RF 

applied. U17B has two parts, one of which serves to invert the logic signal through pin 14 which is the 




inverse of what comes in through pin 16. The other half of U17B switches the signal into the oscillator 

control circuit which causes the oscillator to turn off. This is done when the switch is closed by causing 

the signal to unbalance the oscillator control circuit in such a way that no current can flow to the 

oscillator. Under that condition, C9 is disconnected from the circuit during the measuring period and the 

diode pair, CR1 and CR2, act to clamp the circuit to prevent U14’s output from going more than 1V from 

ground independent of the applied signal. U15 is a comparator that detects whether the output of U14, 

pin 6, is either positive or negative. The output of U15 then goes to the C port of U9 as an input. This 

tells the CPU whether U14’s output is either high or low as determined by the comparator. In the 

measurement mode, there is also a CPU driven successive approximation routine which puts a series of 

words out to the DAC, U10. Then, using standard successive approximation, the voltage level at TP9 is 

determined and placed in memory. On the basis of the voltage placed in memory and knowing the desired 

power out, the CPU can then calculate the voltage that must be written to U10 to control the oscillator 

for the desired output power. To briefly recap, the process is to measure the bridge voltage with no RF 

applied, determine the desired output power, and then write voltage corresponding to that power to the 

U10 DAC. 

When it is required that the oscillator be controlled, the B7 output of U9 will supply a high voltage 

signal to close the switch at C9 and open the switch on CR1 and CR2. C9 then serves to stabilize the 

complete control loop while the thermistor bridge system controls the oscillator. The control system 

operates in the following way. The oscillator provides RF power to the thermistor and, the more RF 

applied, the less dc power is required in the self-balancing bridge. Consequently, as the RF power 

increases the voltage at TP9 will decrease. This voltage feeds into the summing junction at U14. Since 

diodes CR1 and CR2 are switched out of the loop, the feedback circuit then goes from pin 6 of U14 

through R51 to the input of U18D. Pin 11 of U17B is open now, so there is no current fed to U18D from 

that point, and the voltage applied through R51 directly controls the current through Q6. 

R47, R48, R49, R51, R52, U18D, and Q6 form a voltage to current converter. The voltage over R49 will 

equal the input voltage present at R51, but will be shifted to be relative to -15 V (can be read at TP7). 

See Figure 4-3, the current through R49 will be Vin/R49. Assuming that Q6 has a current gain much 

greater than 1, the current driving the oscillator can be approximated to Vin/R49. As the voltage 

increases, the oscillator output power and the RF power dissipated in the thermistor will increase 

resulting in a decrease of the bridge voltage at TP9. 

133.3K 

40.2 Ω 

I out 

V in 

13.3K 

_ 

U18D 

+ 

3.3K 

Q6 

R I 

13.3K 

1K 

-15V 

13.3K 

I out 

= V in 

R I 

Figure 4-3. Voltage to Current Converter 

The decrease of voltage will reflect as a decrease in the level of current and, finally equilibrium will be 

obtained where there is just enough power being supplied to the oscillator to bring the summing junction 

to a balance at U14. The oscillator will then regulate at that level. The net result is that whatever is 




written into the U10 DAC will force the voltage at the thermistor bridge to the desired level to produce 

the required power level from the oscillator. 

U18A is the buffer for the incoming +10V reference voltage. Q10 and Q11 are controlled by the B6 

connection of U9 to provide a signal which can supply current to turn on a relay external to the PPM for 

special applications. 


The test points in Table 4-2 can be checked for the correct signals on the A3 GPIB/Cal Control board: 


Test Point 

TP1 

TP2 

TP3 

TP4 

TP5 

TP6 

TP7 

TP8 

TP9 

+5 V 

5 V Common 

-15 V 

15 V Common 

Description 

Output of the control amplifier for the Calibrator control. Its 

voltage (ranging from a few hundred mV to 10 V) will be related 

to the power required by the Calibrator. 

+15 V 

Measure from TP7 to TP3 to give an indication of the current 

through the oscillator. Will be between 1 and 30 mA. 

+10 V 

Output of the thermistor bridge. Typically will have a voltage of 

about 7 V under ambient conditions. 




4.2.3 CPU PC Assembly (A4) 

See Figure 4-4 and schematic diagram #16879 in Chapter 8. 

Figure 4-4. CPU (A4) Block Diagram 




The CPU (Central Processing Unit) PC board controls all of the functions of the instrument. The CPU is 

logically divided between those circuits shown on Sheet 1 of DWG# 16879 and those shown on Sheet 2 

of DWG# 16879. 

Sheet 1 of DWG# 16879 shows the following CPU functions: 

• The Microprocessor (MPU) 

• Address Decoding and Handshake 

• Unbuffered Memory 

• Reset Timer 

• Interrupt Priority Decoder 

• Data Buffers 

Sheet 2 of DWG# 16879 shows the following CPU functions: 

• External Memory 

• Real Time Clock 

• Backup Battery circuit 

Starting with Sheet 1 of DWG# 16879 and going in the same sequence as shown above, the functional 

operation of each CPU sub-circuit is described as follows: 

The Microprocessor 

The Microprocessor is a Motorola 68000 MPU. It has a 16-bit data bus, 32-bit internal registers, and runs 

on a 6-MHz clock frequency. If you need to see the timing of the MPU in its various modes of operation, 

it is recommended that you refer to the manufacturer’s manual. 

Address Decoding and Handshake 

This circuit performs the address decoding for the memories and other devices included on the CPU 

board and elsewhere in the instrument. It generates the device select signals for the various components, 

creates the proper timing for each device, and performs the necessary handshaking for the transfer of data 

between the CPU and the different devices. 

U18A & B, U20B, and U19C decode address lines 20 through 23 to select the multiplexer U34. The 

address strobe AS is active when the address lines hold a valid address. 

Address lines 16, 17, 18, and 19 select one of the 16 outputs of the multiplexer, which will be used as the 

device select line (CS0 through CS15). CS0 through CS7 address the memories; CS8 through CS13 

address different I/O devices; and CS15 addresses devices that require a handshake according to the 6800 

protocol. 

U15A, U38, U19A, D & E, and U16 create the proper timing and handshaking for each device category. 

When selecting one of the memories, U15A will produce a direct DTACK (Data Transfer ACKnowlege) 

signal to U12 through NAND gate U21C. The MPU will then execute the data transfer without 

introducing any additional wait states. When selecting one of the I/O devices (CS8 through CS13), the 

output of U38D goes high thus enabling the shift register, U16, which is clocked by the 6 MHz system 

clock. After three clock pulses, output QC goes high creating an active CE signal that is used by the 

Analog PC board circuitry. After another clock pulse QD goes high, is inverted in U19A, and creates a 

delayed DTACK through U21C. The MPU responds by inserting a corresponding number of wait states in 

the data transfer which allows the device to time the data transfer. DTACK can also be received from any 

external device connected to the CPU bus that has its own address decoding circuits. 

When CS14 or CS15 are selected, U19E will generate a VPA (Valid Peripheral Address) signal through 

NAND gate U21B. This tells the MPU that a valid 6800 device has been addressed, and the MPU will 

respond by generating a data transfer according to the 6800 protocol. The E and VMA (Valid Memory 




Address) outputs are used in this protocol. There is an external input to the VPA, and the VPA is also 

used in the interrupt process. 

NAND gate U20A and inverter U40A provide an active low signal when a device outside the buffers is 

addressed. 

Unbuffered Memory 

The memory inside the buffers consists of two 8Kx8 bits of RAM and two 32Kx8 bits of ROM with the 

RAMs kept alive by a battery when the instrument is turned off. NAND gate U26D (also battery 

powered) is deselected by the AC FAIL signal when the instrument is off to protect the contents of the 

memory. Each pair of memories use the 16-bit wide data bus and are addressed with one device select 

signal. The upper and lower data bytes are selected in OR gate U14 by letting the Upper Data Strobe 

(UDS) and Lower Data Strobe (LDS) gate the R/W output from the MPU to produce the Lower data 

Write Enable (L.WE), Upper data Write Enable (U.WE), Lower data Output Enable (L.OE), and Upper 

data Output Enable (U.OE) signals. 

Reset Timer 

The U17 reset timer consists of a 555 monostable pulse generator. When the instrument is turned on or 

when the reset button on the back panel is pressed it generates a 0.5 second pulse to reset the MPU. 

U22A & B give separate open collector inputs to the RESET and HALT inputs. U22C provides the HALT 

signal which comes from the Delay board. The RESET pin of the MPU is a bidirectional line, and the 

MPU can generate its own resets. Diode CR1 enables the AC Fail to Halt the MPU. This is necessary to 

ensure that the MPU is not trying to make a data transfer to the non-volatile RAMs or Real Time Clock 

when they are being deselected by the AC Fail signal. 

Interrupt Priority Decoder 

The U37 Interrupt Priority Decoder interfaces the three interrupt priority lines (IPL0, IPL1, and IPL2) to 

the seven interrupt request lines (IRQ1 through IRQ7). The three output lines of U37 will have encoded 

the number of the highest priority input line that has been driven low. As can be seen on the schematic, 

the AC Fail line is connected to the highest priority interrupt input. The lowest priority interrupt input is 

connected to the Real Time Clock for timed interrupts. 

Data Buffers 

Data buffers U7, U8, U9, U13, U32, and U33 give an increased drive capability to all of the signals on 

the CPU bus that require the increased capacity. They are enabled by U40A from the Address Decoder 

circuit. This will happen each time none of the Unbuffered Memories have been selected. The R/W signal 

determines the direction of data flow in the bidirectional buffers used with the data bus lines. 

External Memory 

The External Memory interfaces the buffered CPU bus. It consists of two pairs of 8Kx8 bits of RAM 

(U5, U6, U30, and U31), and three pairs of 32Kx8 bits of ROM (U2, U3, U4, U27, U28, and U29). 

Real Time Clock 

The Real Time Clock, U1, interfaces the Buffered CPU bus. Data transfer follows the 6800 compatible 

protocol with the E and VMA signals to produce the handshaking required for the transfer. U23A & B, 

U24A & B, U25B and U26B control U1. To see the timing used in the data transfer, it is recommended 

that the manufacturer’s data sheet for U1 (Motorola Type MC-146818P) be consulted. C47 adjusts the 

frequency of the internal clock of U1. The 32.768 kHz frequency can be monitored at TP6. The Real 

Time Clock also provides a timed Interrupt Request signal (IRQ1) used by the CPU operating system. Its 

frequency is software programmable, and can be monitored at TP7. The Real Time Clock is deselected by 

the AC Fail line through U26B. 




Backup Battery Circuit 

The CPU board is supplied with backup power from the on-board battery, BT1, whenever the line voltage 

is off or too low to supply the instrument with the required input voltage. Transistor Q1 is turned on by 

the +15 V supply to supply +5 V to the circuits connected to the battery with a minimum drop in voltage. 

While the instrument is turned on, CR2 keeps the battery from being back charged. 


The test points in Table 4-3 can be checked for the correct signals on the A4 CPU board: 


Test Point 

TP1 

TP2 

TP3 

TP4 

TP5 

TP6 

TP7 

TP8 

TP9 

TP10 

Description 

System Clock. 12MHz 

Read/Write signal from U13 

5 V Common 

+5 V 

Reset Signal from U17 

Real Time Clock (U1) Output. Used for Calibration 

Interrupt Request Signal from U1 

Battery Voltage 

15 V Common 

+15 V 




4.2.4 Digital Delay PC Assembly (A5) 

See Figure 4-5, Figure 4-6, and schematic diagram #16686 in Chapter 8. 

The Digital Delay PC board circuitry establishes time delays that may be desired when examining sample 

pulses. Delays can be set in increments of 0.1 ns up to about 430 ms. 

As can be seen in Figure 4-5, there is a complex interaction between each of the sub-functions of the 

delay board circuitry. This section describes the sequence of events that occur in the delay board starting 

with the reset of the circuits, and continuing through the generating of the pulse sample outputs. A 

detailed description of individual circuitry blocks on the Digital Delay PC board follows the sequence of 

events. 

Figure 4-5. Digital Delay (A5) Block Diagram 




The positive edge of the Delay Reset signal at U17A pin 11 will clock the Delay Reset Latch whose 

output will enable the Ramp Control Logic, the Ramp Generator, and the Sample Comparator. The reset 

input of the ramp control flip-flops (pin 13 of U29A and U29B) is released so that another trigger input 

can be accepted. The Ramp Generator switch, U33C, that is holding the output voltage at its initial value 

will open and the Sample Comparator latch, U34, will be released. 

At the time the trigger pulse occurs, the Pulse Stretcher will ensure that only the first positive edge of the 

pulse will be able to trigger the Ramp Control Logic. The ON 1 input will clock flip-flop U29A and its 

output (monitored at TP1) will then activate the following events: 

A. Turn on the Ramp Generator. 

B. Trigger the Voltage Hold circuit to take a 3.3 microsecond duration sample of the Ramp Generator’s 

output voltage and then to hold it. 

C. Enable the Ramp Control Logic flip-flop, U25B so that it can accept the Clock signal for the 

required timing. 

D. Enable the U14 counter. 

The first positive edge of the pulse from the Clock-inverted output at U23B pin 14 will time flip-flop 

U25B to turn off the Ramp Generator and also to enable the Clock Gate. The Ramp Generator output 

voltage will then remain stable while the Voltage Hold function is taking a sample of it. The next clock 

pulse then starts the Counter counting down. When it has counted down to zero, it will cause an inverted 

clock pulse to be gated at its output, U24A pin 6, which will in turn clock flip-flop U25A to turn on the 

Ramp Generator. 

As the output voltage reaches the level determined by the selected delay, the Sample Comparator U34 

will flip and trigger the Pulse Shaper to produce the sample pulses. The output will also turn off the 

Ramp Generator by resetting U25A in the Ramp Control Logic circuit. The Sample 2 leading edge then 

sets the Delay board Reset Latch and the Interrupt Latch, and resets the CPU Interface Halt signal. When 

the instrument is first powered on, the Delay board Reset Latch is set by the Load signal because no 

Sample 2 signal is generated at that time. 

Activation of the Delay board Reset Latch will then cause the following events: 

1. The Ramp Control Logic flip-flops, U25B and U29A, will be reset. 

2. The Ramp Generator output voltage will be reset to +3 V. 

3. A ready signal will be sent to the front panel Ready lamp. 

After the CPU has processed the requested interrupt, it will send a New Data Ack signal to reset the 

Interrupt Latch and the Voltage Hold circuits. 

A very important function in the operation of the delay board is the ability to precisely set a delay using 

a very stable clock with a frequency lower than the resolution of the board, and still be able to accept 

trigger signals that are not in synch with the clock. As can be seen on the Ramp Output Voltage timing 

line in Figure 4-6, the time A from the trigger to the negative clock edge plus the time B from the count 

out negative edge to the set threshold point is always the same. This is one clock period plus the fine 

delay set by the 0 to 25.5 ns Delay DAC plus eventual gate and other delays. These delays are 

independent of the exact timing between the trigger signal and the clock. 




Figure 4-6. Timing Diagram - Delay Board Functions 

The circuitry on the delay board uses both TTL and ECL circuits. Where very high speed of operation 

and/or low propagation delay is required, ECL circuits are used. The logic voltage levels for the ECL 

circuits are -0.81 V to -0.98 V for a logic 1, and -1.64 V to -1.85 V for a logic 0. When an input is 

connected to ground it has a logic 1, and when it is connected to -5.2 V it has a logic 0. (ECL circuits 

use the -5.2 V supply.) Special translators are required to translate between ECL and TTL signal levels. A 

high or low ECL output is always in reference to its non-inverted output. 

CPU Interface 

The CPU Interface forms the link between the CPU bus and all of the sub-functions on the board that are 

controlled by the CPU. The Interface also controls the CPU Halt signal to turn off all action by the CPU 

microprocessor from the time the delay board is triggered until a sample is taken. This serves to 

minimize the noise normally generated by the CPU when an analog signal sample is taken. 

All of the control of the delay board is accomplished through the two PPIs (Parallel Peripheral Interface), 

U6 and U7. They are configured so that all of their total of 48 ports are outputs. Both PPIs are selected 

through the CS10 line. Selection of U6 is done by having the write signal, WR, and the read signal, RD, 

gated by the lower data byte strobe, LDS, signal going to U4A. Selection of U7 is accomplished by the 

action of the upper data byte strobe, UDS, which goes to U4B. Address lines A1 and A2 select one of the 

output ports, A, B, or C, or the PPI control register. 

The delay is determined by the Delay DAC Bus from U6 port A, and by the Digital Delay Bus from U6 

port B and U7 ports A and B. The delay can be set by one single long integer written to the board. The 

selected delay will be the inverted value of that integer. In other words, Delay = the maximum delay 




minus the set value. The trigger level is determined by the Trig Level Bus. It requires 10 bits of data 

which are sent from U6 port C and U7 ports C0 and C1. The trigger is selected by Trig Select 0 and Trig 

Select 1 from U7 ports C2 and C3. The delay board’s interrupt acknowledgment, New Data Ack, comes 

from U7 port C7. 

The Load, Reset, and CPU Halt signals are generated by U1, U2, and U3. If U2 multiplexes U7 ports C2 

and C3 into the Y0 line, it tells the circuit to do nothing. Into the Y1 line means to reset, into the Y2 line 

tells it to load, and into the Y3 line indicates Halt Enable. To set the Halt signal, Halt Enable sets the 

latch U3A. Then, when Y1 is addressed, the following will happen: 

1. The monostable pulse generator, U1, will generate a reset signal at the point where the negative 

edge of the signal at Y1 occurs. 

2. After that, the positive edge of the signal at Y1 will clock U3B which will produce the Halt 

signal. 

The Halt function will be reset by a signal through the Sample 2 line. If no sample has been 

triggered, it can be reset by the CPU Reset or the interrupt requests corresponding to data 

received from the keyboard or through the GPIB. This is done by resetting latches U3A and 

U3B. The Reset also activates the Software Trigger. This will be ignored by the delay circuits 

unless soft trigger has been selected. 

Trig Threshold 

The Trig Threshold circuit sets the level for the internal Trig Comparators. It accepts data from the Trig 

Level Bus, and produces a voltage between 0 and 2.5 V, which is sent to the comparators. 

The Trig Threshold circuitry consists of the 10-bit DAC, U40, amplifier U41B, and associated 

components. Its output is determined by the data present on the Trig Level Bus, and can be monitored at 

TP15. The amplitude range is 0 to 10.23 V with 10 mV resolution. Registers R16 and R17 form a voltage 

divider to give a level between 0 and 2.56 V which is sent to the Trig Comparators. 

Internal Trig Comparators 

The Internal Trig Comparators consist of one fast comparator each for channel A and channel B Internal 

Trigger Signals. The comparators also contain over-voltage protection at each of the inputs to protect 

them against voltages higher than a maximum of 3.0 V. 

The Internal Trig Comparators function is accomplished by using one dual, fast ECL output comparator. 

Its recommended maximum input voltage is 3 V. Each input is protected against over-voltage by an 

identical circuit. On channel A, the input is connected to the emitter of Q13. The base of Q13 is 

connected to 2.1 V which is derived from the +15 V supply through R8 and R9. When the voltage is 

greater than 2.1 V plus the VBE(ON) of Q13, Q13 will then have a low resistance to ground that will 

serve to limit the comparator input voltage. The non-inverted outputs of the channel A and channel B 

comparators can be monitored at TP14 and TP15. 

Trig Select 

The Trig Select is a digital multiplexer that selects either the Internal trigger from channel A or B, a 

software trigger generated by the CPU, or an external trigger from a source connected to the instrument 

rear panel, all controlled through the CPU interface. 

The Trig Select circuitry consists of an ECL 4-wide 4-3-3-3 input, AND/OR gate U30, and a TTL-ECL 

translator, U31, for the trigger select lines. The trigger inputs are active lows, and are selected when the 

two remaining inputs of the OR gate are low. The output goes low when the selected trigger input goes 

low. 




Trig Pulse Stretcher 

The Trig Pulse Stretcher makes sure that the delay board is triggered only by the first leading edge of 

each trigger pulse. It stretches the pulse to 200 ns after the last trailing edge of the pulse. In this way, all 

glitches shorter than 200 ns will be removed from the pulse. Its input comes from the Trig Select circuit, 

and its output goes to the Ramp Control Logic. 

The Pulse Stretcher function is initiated by the monostable multivibrator, U26, which is configured 

through its E+ and E- inputs by flip-flop U29B to accept only a negative sloping trigger, and by the 

2-input OR gate U24C. All action takes place in the ECL format. 

To better understand the operation of the Pulse Stretcher, assume that the output of U29B has been 

clocked but not reset. The input would then be low. When the input goes high, the first thing that happens 

is that the output of the OR gate goes high. Then, the output of U29B will be reset causing the second 

input of the OR gate to go high. When the input goes low it will trigger U26 into generating a 200 ns 

output pulse. U26 can be triggered so that if the input signal contains more pulses that are less than 

200 ns apart, the output will stay low until 200 ns after the last negative edge. When the output of U26 

goes back to the high condition (the reset input of U29A is then low). U29A is clocked and the inverted 

output goes low. Since this means that both inputs of U24C are low, the output of the Pulse Stretcher will 

now go low. 

After the PPM is first turned on, it is necessary to give the Pulse Stretcher one trigger input pulse 

(generated by the soft trigger function) to initialize it. 

Clock 

The Clock is a stable crystal controlled square wave generator. It operates at 39.0625 MHz to give a 

25.6 ns period. 

The Clock consists of U23A,B & C, and Y1. U23A is a positive feedback amplifier with the Y1 crystal. 

U23C provides a dc bias to the input and U23B is an output buffer. The frequency is adjusted with C79. 

The clock frequency can be measured with a high impedance probe at TP5. 

Clock Gate 

The Clock Gate provides the timing to the Counter when either in the count mode or in the delay data 

mode. When counting, the clock is enabled with a clock enable signal from the Ramp Control Logic and, 

when loading, it is enabled by a load signal from the CPU Interface. 

The Clock Gate consists of AND gates U28A and U28B whose outputs are OR’d in U27C. The clock is 

connected to both U28A and U28B, and can be gated by either the load signal on U28A pin 4 or by the 

Ramp Control Logic Out 2 on U28B pin 7. 

Counter 

The Counter establishes a coarse delay time. It is controlled by the Digital Delay Bus and the load signal 

from the CPU Interface. The clock gives it a resolution from 25.6 ns to a maximum delay of about 

430 ms. The output is the selected clock pulse with just one gate delay with respect to the clock. 

The Counter consists of high speed ECL binary counter U14, five TTL binary counters U9, U12, U11, 

U10, and U9 (with the first one being S-TTL), and the clock input. ECL delay data is translated from 

TTL by U13. It is clocked from the Clock circuitry. During the delay count, the multiplexer U16 selects 

the Terminal Count (TC connection) of U14 as the clock input to U8, and the Carry Out (CO connection) 

of U8 as the clock input to U12, U11, U10, and U9. U11, U10, and U9 operate in a look-ahead, carry 

mode. U19A, U20A, and U24A are using the U8 Terminal Count and the U8 and U9 Carry Out to select 

the first clock pulse after the counter has counted up to a full count. 

When all of the counters are loaded, they have to be provided with one clock pulse while the Load input 

is low (Parallel Enable for U14) to execute the load. In U14, this is done by the Clock Gate circuit. For 




the other counters, the load signal will be executed by having the multiplexer U16 delay the negative 

edge of the signal and inverting the signal using U15A, B & C. 

Delay Board Reset Latch 

The Delay board reset latch resets the board to accept the first trigger pulse after the reset is 

accomplished. The reset signal comes from the CPU through the Interface. The Latch resets the Ramp 

Control Logic, the Ramp Generator, the Voltage Hold, the Sample Comparator latch, and the Ready 

output that controls the Ready and New Data lamps on the front panel of the instrument. 

The Delay board Reset Latch function is accomplished by flip-flop U17A. Inverter U15E and NAND gate 

U20D are used so that U17A can be set by both the Sample 2 and Reset signals. 

Ramp Generator 

The Ramp Generator produces an accurate ramp for the 0 to 25.6 ns delay. The Reset input presets the 

voltage at the output to a 3.0 V bias. When turned on by the ON/OFF input, the voltage drops at a rate 

that can be adjusted with the Delay Adjust potentiometer. The output voltage can be held at a fixed value 

for a long period of time with the Voltage Hold circuit. 

The Ramp Generator is driven by a dc current sink consisting of U32A, Q9, and Q10. U32 compares the 

voltage at R32 with a voltage reference provided by CR2, R29, R30, and R31. The output of U32, 

boosted in darlington configuration, will regulate the current through R32 to I = Vref/R32. The current 

which forms the slope of the ramp is adjusted by R30 (DELAY ADJ). Q5 and Q6 are configured as a 

differential pair driven by the differential outputs of the ECL gate U27B. When the Ramp Generator is 

off, the current flows from ground. When it is on, it discharges C14 at a rate equal to dV/dT = I/C. The 

starting voltage is provided by the +10 V reference through R44 and R45 when switch U33C is closed. 

Voltage Hold 

The Voltage Hold circuit holds the output voltage of the Ramp Generator during the time it is waiting for 

the count output from the Counter. It consists of a double buffered sample and hold amplifier with input 

and output tied together. It is reset by the New Data Ack signal from the CPU Interface. The Sample 

input from the Ramp Control Logic samples the voltage for 33 µs and then holds the voltage. The hold 

mechanism only prevents the voltage from increasing, not from decreasing. A controlled current leakage 

ensures that the droop of the voltage is positive, and thus is taken care of by the Voltage Hold circuit. 

The Voltage Hold circuit consists of amplifiers U37A & B, analog switches U33A & B, monostable 

vibrator U22A, and NAND gates U20B & C. The output of U37B sinks all leakage current injected to the 

Ramp Generator output voltage mode. R46 provides a controlled leakage to ensure that the leakage is 

positive. Diode CR1 ensures that U37B will not prevent the voltage from decreasing when the Ramp 

Generator is turned on. U37’s output voltage can be monitored at TP9. U37A serves as a buffer amplifier. 

Its output can be sampled and held by analog switches U33A & B. Before the sample is taken, U33B is 

closed to keep the voltage at 3.0 V. When the sample is triggered, U22A produces a 3.3 µs pulse closing 

U33A. The leading edge of the pulse will also set the flip-flop formed by U22B & C whose output will 

open U33B. During the sampling period, C9 will be charged and will then hold the voltage. 

Sample Comparator 

The Sample Comparator compares the output from the Ramp Generator with the output voltage from the 

0 to 25.6 ns Delay circuit. It has a latch input from the Delay board Reset Latch. The latch prevents any 

change in the output of the comparator from the time the sample is triggered to the time the delay board 

is reset so that no spurious samples will be taken. 

The Sample Comparator consists of ECL comparator U34, Q7, and Q8. Q7 and Q8 increase the input 

impedance of the comparator, and to stabilize the input bias current. U34 has a latch input that will keep 

the output of the comparator from changing when driven ECL low. U34’s output can be monitored at 

TP11. 




Ramp Control Logic 

The Ramp Control Logic controls the sequence of events that are required to generate the selected time 

delay. The Reset input enables the circuit to accept the first positive edge from the trigger pulse. The ON 

1 input accepts the trigger pulse to turn on the Ramp Generator, enable the Counter, and to initiate the 

Voltage Hold. The OFF 1 input, consisting of the first negative edge of the clock signal after the trigger, 

turns off the Ramp Generator and enables the Clock Gate. The ON 2 signal comes from the Counter’s 

count output and turns on the Ramp Generator. The OFF 2 signal consists of the Sample Comparator 

output which turns off the Ramp Generator when the sample is taken. 

TP1 can be used as an oscilloscope trigger when testing the Delay board. 

Zero to 25.5 ns Delay 

This circuit consists of a DAC controlled by the Delay DAC Bus through the CPU Interface circuitry. It 

sets the proper levels for a delay between 0 and 25.5 ns with an accuracy of 0.1 ns. Its output goes to the 

Sample Comparator. 

The 0 to 25.5 ns Delay is set by the 8-bit DAC U35 and amplifier U32B. The output is biased by R37 

from the +10 V reference, and has a range of -0.5 V to +0.994 V full scale with 5.86 mV resolution. The 

output voltage can be measured at TP6. 

Pulse Shaper 

The Pulse Shaper is triggered by the Sample Comparator and provides the sample signals to the samplers 

on the analog boards. It also provides a synch signal to the rear panel SYNCH OUTPUT connector of the 

instrument. The synch signal is simultaneous with the 15 ns wide Sample 1 signal. The Sample 2 signal 

is also used in the CPU Interface to end the halt signal to the CPU. Sample 2 also goes to the Interrupt 

Latch and the Delay board Reset Latch to prevent any triggering from occurring until after the delay 

board has been reset. 

The Pulse Shaper consists of an ECL monostable multivibrator, U38, which will provide a 15 ns pulse. 

U35 provides buffered differential outputs to the Sample 1 line and the Synch Out signal. U22 provides a 

4.3 ms Sample 2 pulse. 

Interrupt Latch 

The Interrupt Latch output goes directly to the CPU interrupt request input to alert the CPU that a sample 

has been taken. It is reset by the New Data Ack signal coming from the CPU Interface when the analog 

board has finished with the sampled voltage. 

The Interrupt Latch consists of a D-type flip-flop, U17B. It is clocked by the Sample 2 line to produce an 

interrupt request New Data signal to the CPU, and is reset through the New Data Ack. line. 





The test points in Table 4-4 can be checked for the correct signals on the A5 Delay Line board: 


Test Point 

TP1 

TP2 

TP3 

TP4 

TP5 

TP6 

TP7 

TP8 

TP9 

TP10 

TP11 

TP12 

TP13 

TP14 

TP15 

TP16 

TP17 

TP18 

Description 

Output of U29A. Trigger signal that tells when the board has been 

triggered and reset. Can trigger a scope when testing the board. 

Signal goes low at trigger and high at sample time. 

-5.2 V 

5 V Common 

+5 V 

Clock Frequency (C79 adjusts) 

Output of U36, U37 DAC, which determines the 0 to 25.5 ns 

threshold. 

U34 comparator input 

U34 comparator input 

U37B hold amplifier output 

10 V Reference 

U34 comparator output 

5 V Common 

U39 comparator output (trigger signal) 

U39 comparator output (trigger signal) 

U40. Trigger level DAC 

+15 V 

15 V Common 

-15 V 




4.2.5 Analog PC Assembly (A6/A7) 

The Analog PC circuitry accepts, converts to digital, and conditions the analog voltage coming from the 

channel A and B RF detectors. A6 is the reference designation for the channel A board, and A7 is the 

designation for the channel B board. Both boards are configured the same. The Model 8501A meter uses 

only A6. 

Refer to Figure 4-7 and sheet 1 of schematic diagram #20742 in Chapter 8. 

Figure 4-7. Analog PC (A6/A7) Block Diagram 




The signal from the delay line is applied to a fast sample and hold circuit (CR16 to 19 and U29) with a 

sample pulse width of 15 ns. Next is a second sample and hold circuit (U28) with a pulse width of 

approximately 4 µs. The second sample and hold circuit is to ensure that the sampled signal that is 

present will not change in amplitude while it is being held. The signal is held during the time from when 

the sample is taken to the completion of the data conversion cycle. U28 can either use the sampled signal, 

or take the signal directly from the input without using the sampling circuitry. 

There are four stages of gain available after the signal reaches U28. The gain can be either 1 or 8 through 

each stage. The circuits are composed of U27 with a fixed gain of 2, amplifier U26, U18, low pass filter 

U19, U11 which is the third gain stage, and U12 which is the amplifier for the fourth gain stage. All four 

stages are used only in the CW mode and give a total gain of just over 8,000. In the peak pulse mode the 

last two amplifiers (U11 and U12) are not used, so the total gain will be 64. 

After the four gain stages, there is a multiplexer circuit that allows the selection of either the measured 

signal from the detector or the voltage from the thermistor in the detector. U21B will generate a voltage 

proportional to the thermistor temperature. This voltage goes to U20, and then to the ADC. 

U16, U17A, B & C, and U9 comprise a circuit that will give the absolute value and determine the 

polarity sign of the signal. U16 ensures that the voltage is steady during the conversion time. It receives 

the status (when conversion is occurring) from A to D converter U7. The D to A conversion circuit 

formed by U8, U14A, and U21A give an analog output proportional to the power level being sensed by 

the detector. 

The system 10 V reference voltage comes from the U7 A to D converter. U14C gives the +10 V 

reference, and U14B gives the -10 V reference. During the automatic self test routine of the instrument, 

the signal from the DAC (U8, U14, and U21) is tested to assure that these components are operating 

properly. 

As an example of signal flow through the analog circuitry, when the first signal sample is directed to the 

fast sample and hold circuit, it comes in through the Sample 1 line (on the left side of the schematic) as a 

balanced ECL signal, and then goes to differential receiver Q2 and Q3. 

When a trigger is sent, Q2 produces a current pulse to trigger blocking oscillator Q4. The blocking 

oscillator generates a 20 V pulse approximately 30 ns long at the secondary of T1. This pulse overcomes 

the reverse bias normally applied to the sampling bridge (CR16 - CR18), and drives a heavy current 

through it, thus connecting sampling capacitor C72 to the input signal during the sampling interval. 

R120 gives a controlled discharge of C72 between the samples. This is done so that whenever a sample is 

to be taken, C72’s voltage is close to zero to set it to the same condition for each of the samples. The 

reason for this is to assure repetitive accuracy for every sample of the specific signal being measured. 

U29 is a high impedance amplifier. 

The second signal sample comes into the board through the line labeled Sample 2, and goes to a circuit 

which includes switch U25D, holding capacitor C70, and isolation amplifier U28. R136 serves the same 

purpose as R120 (to control C70’s discharge). Setting the zero (or close to zero) dc offset level required 

while sampling is in progress is controlled at R112 (Sample Zero), and can be monitored at TP5. 

Selection between the CW or peak power mode signals is through the U25A & B switches. U25A & B 

can also select the +15 V signal through U13A. This allows the gain of the various stages to be separately 

checked using a known input. U27 has a fixed gain of 2. U25C (on the negative input of U27) is 

permanently closed, and improves the common mode rejection of the amplifier. 

Each of the four selectable gain stages are identical. The first is a comparator (U23) where the input 

signal is compared with a fixed level. Then, the signal from each of the stages is sent to the U6 latch. U6 

can operate in several different modes. When measurements are being taken, the latch is in the 

autoranging mode. This means that the inputs for the latch are the signals from the comparators. The 

outputs, which directly follow the inputs in the autoranging mode, are controlling the switch and the gain 

circuits. The first gain stage, U22A, determines whether the gain will be 1 or 8 by selecting different 




feedbacks. If the routine is in a mode where several samples are being averaged, the first sample will be 

in the autorange mode and be amplified by the selected gain. 

When autoranging is inactive (latch output is high impedance), the latch interfaces with outputs from the 

CPU to allow the CPU to control the gain. This mode is used during calibration or self test to allow the 

gain to be manually selectable. 

U19 is a filter that can be selected to be either in or out of the gain loop. In the CW mode it is in the 

loop, but in the pulse mode it is not used to allow for a faster settling time during the analog to digital 

conversion. U19 is switched in or out of the loop by U15A. 

U16 is an integrated sample and hold amplifier directly controlled by the status signal from the U7 A/D 

converter. When U7 is given the command to convert, the status signal goes active and stays active until 

the conversion has completed. Then U17B, C, and D rectify the signal to give a positive output that is 

sent to one of the inputs of the U6 latch. Input 2D1 of U6 determines the positive or negative status of 

the signal. U7 interfaces directly to the data bus, and has a built-in 10 V voltage reference used 

throughout the system. R13 adjusts the value of the 10 V reference. 

The thermistor interface circuit, U21B, uses the resistance of the detector’s thermistor in conjunction with 

the 10 V reference to determine the temperature of the detector diodes. This output is then sent to the 

U20 multiplexer. 

U8 is a 12 bit DAC. U21 gives a fixed offset so that there will be a resolution of exactly 2 mV 

corresponding to 0.02 dB when R47 is adjusted to the proper gain setting. The total range is from +30 to 

-50 dBm. 

Refer to sheet 2 of schematic diagram #20742. The board first has an RC network that compensates for 

the frequency dependent losses in the delay, to assure correct pulse response. The signal is sent from the 

board to the delay line. Sheet 2 also shows the buffer amplifiers used with the trigger signals and monitor 

outputs. The input to these amplifiers comes from the detector output voltage before it reaches the delay 

line (at the point where the detector cable interfaces with the instrument). PPI U1 has all of the output 

control signals and status inputs as well as an interface to the CPU bus. 

The trigger amplifier consists of OpAmp U30, high speed buffer U31, analog switch U32, and peripheral 

circuitry. U30 and U31 form a composite amplifier with U31 transmitting the ac information through 

C106, and U30 transferring the dc information through R165. R113 adjusts the dc offset of U30. Analog 

switch U32 sets the gain of U30 either to unity or to 10. In the X10 gain range the rise time of the 

trigger signal is slower. The monitor output is taken from U33, and is not corrected for offset. 

U2A, B, C & D and U3A, B, C & D are the final address decoders. The chip select line, the Address line 

(A14), and data strobes choose whether to activate the A to D or D to A converter, or to activate PPI U1 

which is controlled by the data bus and will interface read or write signals through the A1 and A2 lines. 

Sheet 3 of DWG# 20742 shows the voltage input and grounding configurations for all of the IC’s on the 

Analog PC board. 




A6/A7 Test Points 

The test points in Table 4-5 can be checked for the correct signals on the A4 CPU board: 

Table 4-5. A6/A7 Analog Test Points 

Test Point 

TP1 

TP2 

TP3 

TP4 

TP5 

TP6 

TP7 

TP8 

TP9 

TP10 

TP11 

TP12 

TP13 

Description 

Reference Common 

+10 V Reference 

Output of the analog DAC 

Analog output as seen on the rear panel connection 

Output of the 2nd sample and hold 

+5 V 

5 V Common 

-5 V 

+15 V 

-15 V 

15 V Common 

Can be used as scope trigger 

0 Vdc adjust readout point 




4.2.6 Front Panel Interface PC Assembly (A8) 

The Front Panel Interface PC board powers and controls the instrument display (through U1, U2, U3, and 

U7); provides the interface to the keyboard and front panel indicator lamps (through U2, U4, and U7); 

and interfaces with the spin knob on the front panel. 

Refer to Figure 4-8 and sheet 1 of schematic diagram #20196. 

Figure 4-8. Front Panel Interface (A8) Block Diagram 




U11 interfaces with the CPU, the data bus, chip select lines, read/write lines, the A1 address line, and the 

clock input line. The output of U11 goes directly to the display. U1 is a 69K RAM to store what is being 

shown on the display. This means that there is a separate data address and data bus between U11 and the 

U1 memory. U2 (the display and keyboard interface) has logic for the selection of the read and write 

functions. It has a number of scan lines (outputs) designated SL0, SL1, SL2, and SL3 that go to the 

keyboard. Connection is made between one of the lines and one of the return lines (RL) to tell the 

circuitry which key was pressed. The scan lines are also connected to the peripheral drive circuit so that, 

together with the output lines A0 through B3 (connected to U7), the control of which indicator lamp is to 

be turned on is accomplished. 

Refer to Sheet 2 of schematic diagram #20196. The circuit receives its input from the stepper motor that 

interfaces with the spin knob on the front panel. The output is a signal that corresponds to 16 different 

keys in the keyboard interface circuitry. Each one is equal to a speed at which the stepper motor is being 

turned. Also, there are two other lines on the interface IC (U17B) that sense that the spin knob is in use 

and what direction it is being turned (U12B through RL0 through 7, and SL0 & 1). This signal is input to 

U14A & B. 

The stepper motor creates two sinusoidal signals that are 90 degrees out of phase with each other. The 

voltages of these signals are proportional to the speed of rotation of the spin knob. That is, the higher the 

frequency (speed of rotation), the higher the voltage. U14A & B are low pass filters with the cut-off 

frequency determined by the slowest speed the spin knob can be turned (a small fraction of a Hertz). As 

the frequency increases, the level builds until it reaches a constant amplitude. The amplitude is input to 

timers U8A & B and used so that if the input level is above 2/3 of the level of the supply voltage, then 

the output will be high. If the input goes below 1/3 of the supply voltage level, it will go to zero. The 

function is similar to a Schmitt trigger with levels of 1/3 and 2/3 of the supply voltage. 

U8A & B output a train of square waves which are also 90 degrees out of phase with each other. The 

square waves go through RC networks, and then give four inputs to U10. Each one of the inputs 

represents an up or down-going edge of one of the U8A & B square waves. The output is a pulse train of 

short pulses that indicate when the spin knob is being moved. U21A receives the pulse train, and U17A, 

B, C & D decode the direction of movement. If the knob is turned in one direction, U21B will have the 

same pulse train. When the knob is turned in the other direction, the pulse train will not be present. 

Flip flop U18A is a gate controlled by the data input signal. From U12A the signal goes to monostable 

oscillator U17A so that when the knob is first turned an approximate 100 ms pulse is generated (read at 

TP6). While this pulse is high, the U16 4-bit counter counts the number of pulses from the spin knob. 

The more pulses that are counted, the faster the rotation of the knob. When the count reaches 15, a carry 

out is generated and U9B stops the counter from starting back at zero. Thus the maximum count of 15 is 

preserved, indicating the fastest spin knob rotation. When the U17A 100 ms timer ends, the U17B 

monostable outputs a SHIFT signal for approximately 20 ms. This tells the U2 keyboard decoder that the 

spin knob was moved. The four bit count from U16 is coded onto RL0 - RL7 by the U5 demultiplexer 

and part of PAL U10. PAL U10 gates the scan lines SL0 and SL1 with the highest order bit from U16 to 

control U5. If the count is 0 - 7, the three lower order bits from the counter are coded onto R0 - R7 by 

U5 when SL0 goes high. If the count is 8 - 15, the three lower order bits are coded out when SL1 goes 

high. The state of the CNTRL signal from flip-flop U18B indicates whether the spin knob was turning 

clockwise or counterclockwise. 

Refer to sheet 3 of schematic diagram #20196. This is the circuitry which supplies power to the display. 

Linear regulator U22 regulates the +12 V down from the unregulated +20 V. The higher voltages are 

stepped up from the unregulated +20 V by a switching fly-back power supply. U19 is a current mode 

switching regulator IC which runs the supply. U19 controls the output voltages by varying the duty cycle 

of FET Q1, the power switch. The current through Q1 is limited by U19-3 which monitors the voltage 

across sense resistor R44. The rise time of the flyback voltage is controlled by a damping network 

composed of C60, R32, and R41. The frequency of U19 operation is fixed at about 100 kHz by timing 

components R37 and C53. 





The test points in Table 4-6 can be checked for the correct signals on the A8 Interface Assembly: 

Table 4-6. A8 Interface Assembly Test Points 

Test Point 

TP1 

TP2 

TP3 

TP4 

TP5 

TP6 

TP7 

TP8 

TP9 

TP10 

TP11 

TP12 

Description 

5 V Common 

Clock - 2 MHz 

+5 V 

Shift Signal 

I Sense 

Timer (100 ms pulse from spin knob movement) 

Flyback 

-HV 

+HV 

+20 V Unregulated 

+MV 

A Ground 




4.2.7 Calibrator PC Assembly (A12) 

Refer to Figure 4-9 and schematic diagram #17097 in Chapter 8. 

The RF Diode Detector Automatic Calibrator uses a computer-controlled calibration circuit to generate 

precise calibration data using a simple power meter (thermistor) as a reference. This permits diode 

detectors to be used for absolute power measurements with the same accuracy usually associated with 

thermistor power meters. 

Since the automatic calibration system is a new concept developed by Giga-tronics for calibrating diode 

detectors, the first portion of this discussion will be a general description of the overall theory involved 

in the system operation. The last part of the discussion will cover the operation of the specific 

components contained in the calibrator assembly. 

Figure 4-9. Detector Calibrator (A12) Block Diagram 




The system consists of an amplitude-controllable oscillator operating at a fixed frequency of 1 GHz. A 

portion of the RF output is coupled into a thermistor leveling circuit which is physically mounted inside 

the metal housing of the calibrator assembly. Referring to Figure 4-9, the thermistor is maintained at a 

fixed resistance by applying a dc bias current through it. This is achieved by using a self-balancing 

Wheatstone bridge with the thermistor inserted in one leg of the bridge. The amount of power required to 

maintain the thermistor at the fixed resistance, RT, is constant so that the RF power plus the dc power 

dissipated at the thermistor equals a constant. This constant can be determined by switching the RF 

power off and measuring the bridge voltage. 

The oscillator output power can then be set by measuring this ambient bridge voltage and calculating the 

dc voltage which would balance the bridge when the oscillator has the required power output. When this 

required bridge voltage is written to the DAC on the GPIB/Cal Control PC board, the feedback causes the 

oscillator to settle to the selected RF power. 

The above technique allows the calibrator output power to be precisely controlled over a dynamic range 

of approximately 15 dB. The dynamic range is increased by passing the oscillator power through a set of 

switched attenuators. The attenuators are designed to allow attenuation values of 0, 10, 20, 30, and 

40 dB. The overall gain is adjusted so that the 20 dB stage will provide a precise 0 dBm reference with a 

specific power level out of the oscillator. 

Integrated control of the calibrator and detector permits errors in the other attenuator stages to be 

completely removed in the following manner. 

With a particular attenuator switched in, the processor sets the oscillator output power to precisely 9 mW 

and measures the detector voltage. The next level of attenuation is switched in, and a successive 

approximation algorithm finds the oscillator power (about 90 mW) which will give precisely the same 

detector voltage. By dividing the two powers, the relative attenuation of the two ranges is obtained. Since 

the 20 dB range is adjusted to give a 0 dBm absolute reference, the absolute effective attenuation of each 

range can be calculated. 

The automatic calibration system generates a table of detector voltages that are equivalent to a known 

level of input power. This is done by applying many different input powers to the detector, measuring the 

amplified detector output, and storing the result. The calibration procedure is completely automatic, and 

the entire process including the range switching, attenuator measurements, and detector calibration takes 

less than one minute. 

Since there is 15 dB of dynamic range in the thermistor leveled oscillator and 40 dB of attenuation 

available for insertion, the calibrator operates over a total 55 dBm dynamic range. Below -33 dBm, the 

diode detector itself is linear (square law), so the total dynamic range of the system will be 60 dB (-40 to 

+20 dBm). 

The frequency response of each individual RF detector is measured over its entire specified range at the 

factory, and the information is stored in a ROM that is an integral part of the detector. Then, during the 

measurement of an unknown signal, the frequency response information contained in the detector’s ROM 

and the amplitude table generated by the calibration system are combined so that if a voltage equal to, 

say, -10 dBm is generated by the calibrator, the instrument looks at that voltage, compares it to its table, 

and by interpolating between data points knows that specific voltage level equals -10 dBm. In this way, 

offset and gain errors in the detector amplifiers are removed and the system has the capability of 

measuring power over the full dynamic range of the detector with just as much accuracy as the power 

that is produced from the calibrator. 

Refer now to DWG# 17097. Q1, together with the Base and Emitter Resonators, is the 1 GHz 

controllable oscillator. A portion of the signal from Q1 is coupled to a thermistor leveling circuit through 

the Low Pass Filter to remove harmonics, and through the quarter wave choke to allow connection to one 

end of the thermistor, RT1. The other end of the thermistor is connected to RF ground through an RF 

bypass line labeled FL5. RT1 samples the RF signal at the output of the low pass filter, and that sample 

is sent to the control circuitry on the GPIB/Cal Control PC board. The control circuit has a feedback 

system involving some amplifiers and associated circuitry as described in the GPIB/Cal Control board 




discussion. The output from this feedback system controls the Q1 oscillator so that the total power in 

RT1 is maintained at a constant level. 

Following the thermistor leveling circuit is a series of pin diode attenuators comprising three stages of 

attenuation (10 dB, 10 dB, and 20 dB) for a total capability of 40 dB. These stages are switched in and 

out by control signals from the GPIB/Cal Control board. In the first 10 dB stage, if the current through 

the attenuator is flowing in the direction required to turn on the series diode, CR2, then the attenuator is 

bypassed and minimum attenuation occurs. If the control current is in the other direction, CR2 is turned 

off and CR1 and CR4 will conduct so that 10 dB of signal will be lost. The other stages are similarly 

switched in and out to allow attenuation from 0 to 40 dB in 10 dB stages. The output then goes to the 

CAL connector. 

R3 supplies current from the -10 to -13 V control voltage source to the emitter of Q1, and R1 and R2 are 

bias resistors to provide a -10 V bias to the base of Q1. 






5 

Testing and Calibration 

5.1 General 

This chapter is a procedural guideline for performance evaluation and calibration of the 8501A and 

8502A Peak Power Meters (PPM) and power detectors. These tests can also be used for performance 

testing when the instrument is first received. 

The Information in this chapter can be used to calibrate and/or confirm calibration of the PPM and its 

detectors, using the built-in automatic detector calibration system. 

The performance tests are valid only if the detector has been automatically calibrated at an ambient 

temperature between 15 and 35 °C (59 and 95 °F), and is operating within ±5 °C (±9 °F) of this 

temperature at the time of calibration. 

If the PPM has not been previously used, you should review Chapter 2 of this manual to ensure that 

power requirements and detector precautions have been complied with before the instrument is turned on. 

The instrument has been factory-calibrated and should not be re-calibrated before the performance tests 

detailed in this chapter have been completed. Before starting the performance test procedures, the 

instrument should be warmed up for at least 30 minutes for maximum stability during testing. 

Performance test data and calibration recording sheets are located at the end of this chapter. These sheets 

can be copied and used for recording the results each time performance tests and calibration are 

performed on the instrument. 




5.2 Performance Testing 

The tests in this section are to determine that the performance of the Model 8501A or 8502A Peak Power 

Meters (PPM) is within the parameters of the specifications given for the instrument. Assemble all of the 

required test equipment and the PPM to be tested. Connect all equipment to the ac power line, turn it on, 

and allow at least 30 minutes for it to warm up before starting the test. 

5.2.1 Equipment Required 

The equipment listed in Table 5-1 is required for Performance Testing. Equivalent or similar test 

equipment can be substituted. 

Table 5-1. Required Test Equipment 

Description Representative Model Key Characteristics 

CW Thermistor Power Meter HP Model 432B Instrument accuracy of at least 

0.5% 

Thermistor Mount HP Model 8478B ≤1.1 SWR @ 1 GHz 

Digital Voltmeter (DVM) Fluke Model 8600A ±0.05% accuracy 

Directional Coupler Narda Model 3002, 10 dB ≤1.15 SWR @ 1 GHz 

Step Attenuator, 0 to 50 dB in 

10 dB increments 

Weinschel Model 1 

≤1.15 SWR @ 1 GHz Accuracy 

+20 dBm @ 1 GHz & pulse mod 

Low Pass Filter HP Model 360B >30 dB attenuation @ 2 GHz 

Precision Pulse Generator Wavetek Model 178 10 ppm Frequency Accuracy 

Return Loss Bridge Wiltron 63N50 or 97NF50 Directivity 36 dB. Freq. Range 

from 1 GHz to max. freq. of 

detector in use 

Scalar Network Analyzer Giga-tronics Model 8003 Frequency Range as above 

Precision DC Source Datel Model DVC 8500A 0.05% Accuracy 

Graphics Plotter HP Colorpro Model 7440A GPIB compatible 




5.2.2 Calibrator Return Loss Test 

Set up the scalar analyzer, signal generator, and the Return Loss Bridge to measure 0.95 to 1.05 GHz. 

Connect the bridge to the Calibrator output on the front panel of the PPM. The return loss must be 

>25 dB over the frequency range. 

5.2.3 Calibrator Output Level Test 

The following test will check the absolute level of the Calibrator function of the PPM. Note that 

verifying the level is not the same as setting the level. When the calibrator was previously adjusted, it 

was done using equipment capable of setting it to a level within the specifications of the instrument. The 

equipment used to verify the value also has its own uncertainties. Due to the nature of the measurement, 

equipment does not exist to make it practical to require a ten times (or even 3 times) accuracy difference 

between the specified performance and the specified accuracy of the measuring equipment. Therefore, the 

uncertainty allowed for this test reflects both the uncertainty of the calibrator and the uncertainty of the 

power meter used to verify it. 

1. Place the PPM in the CW Mode by pressing [CW], then press [MENU] and select Calibration. 

When the Calibration/Zeroing menu appears, press [F1] and then immediately press [7]. Be sure 

that the Thermistor Power Meter is zeroed. Connect it to the Calibrator output connection and set 

it to the 1 mW range. The calibrator should read 1 mW. To be sure that the measurement is 

correct, the following steps must be performed exactly as given. Under no circumstances should 

any key be pressed other than the ones specified. 

CAUTION 

Do not press any UNITS key when the thermistor detector is connected to the 

calibrator. This would cause the calibrator to output 100 mW, and would possibly 

destroy the thermistor detector. 

2. Press [CLEAR], then zero the Thermistor Power Meter. 

3. Press [7] and read the Thermistor Power Meter. Take note of the meter reading. 

4. Repeat Steps 1 and 2. Average six readings if successive readings are taken. 

5. Disconnect the Thermistor Power Meter from the Calibrator connection. 

The average reading in Step 3 should be 1.000 mW ±4.5% after correcting for the calibration factor of 

the thermistor mount at 1 GHz. Note that an uncertainty smaller than 4.5% can be supported by this 

technique if the calibration factor of the detector has been determined by a primary standards laboratory 

such as the NIST (formerly NBS). This value merely reflects standard current commercial practice. 

5.2.4 Instrument Plus Power Detector Linearity Test 

Connect the test setup as shown in Figure 5-1. The linearity will be tested in a series of 10 dB steps over 

the range of the instrument. At low power levels, the linearity measurement will reflect the uncertainty 

due to the noise specification. Measurements will be made in both the CW and Peak Modes. 

Refer to the CW Linearity Data and the Peak Linearity Data sections of the Test Data recording sheets at 

the end of this chapter. These sections will facilitate the collection of data for the CW and Peak power 

linearity test. The tolerance is already entered in each section for the various steps, and includes an 

allowance for specified noise errors at low power levels. 




5.2.5 Power Linearity Test Setup 

Figure 5-1. Power Linearity Test Setup 

To make accurate measurements using the thermistor power meter, it is essential that it be zeroed 

properly. This should be checked frequently, keeping in mind that the instrument must be zeroed again if 

any drift has occurred. 

For each value of attenuation the following steps are to be performed: 

1. After initial power-on and warm up, set the PPM to read CW power in milliwatts, with the CW 

averaging number set to 500. This is done by pressing [CW] [MENU] (2) [F1] [500] [UNITS] 

2. Check that the display indication is in milliwatts. If not, press [MENU] (4) [F3]. 

3. Be sure that the RF source is set to 1.0 GHz. 

4. Perform an automatic calibration on the detector (use channel A for an 8502A). Use this detector 

for the rest of the test. 

5. Automatic calibration is performed by first attaching the detector to the 1 GHz Calibrator 

connection on the front panel of the PPM, and then pressing [MENU] (1) [F3] [F1] [UNITS] 

6. Be sure that the Thermistor Power Meter is zeroed correctly. Adjust the RF source for a reading 

of 10.0 mW ±0.25 mW. 

7. Record the Power Meter Reading and the PPM Reading in the corresponding columns of the CW 

Linearity Data section of the Performance Verification Test Data recording sheet. 

8. Adjust the source to read 1.0 mW ±0.025 mW. 

9. Record the Power Meter Reading and the PPM Reading in the corresponding columns of the Test 

Data recording sheet. 

10. Calculate the power ratio and reading ratio (using P1/P2 and R1/R2), and record these values in 

the indicated columns of the Test Data recording sheet. 

11. Calculate the linearity error using the formula: 

Linearity error (%) = [(R1/R2) / (P1/P2) - 1] * 100 




12. Record this value in the Linearity Error column (above the Accumulated Error figure given for 

each attenuation value) in the Test Data recording sheet. This value should be less than the value 

specified for Accumulated Error for each attenuation level. 

13. Add an additional 10 dB of attenuation between the coupler and the Peak Power Detector, and 

repeat Steps 6 through 12. The next lower rows of the CW Data section of the Test Data sheet 

will be used to record the readings taken for the 20, 30, 40, and 50 dB attenuations as Steps 6 

through 12 are repeated for each level of attenuation. Add the previous and current linearity 

errors to determine the accumulated error. 

14. Set the Pulse Generator to generate 5 V pulses (TTL) with 10 µs duration and a repetition rate of 

1 kHz. Connect the Pulse Generator output to the TRIG Input on the rear panel of the PPM. 

15. Set the PPM to use an external trigger in the Peak Mode, milliwatts display, and peak averaging 

set to 100. This is done by pressing [PEAK] [MENU] (1) [F2] [MENU] (2) [F2] [100] [UNITS] 

(If the display indication is not in milliwatts, press [MENU] (4) [F3]). 

16. Remove all attenuators and repeat Steps 2 through 9 for the Peak Mode, recording the test 

indications in the Peak Linearity Data section on the Test Data recording sheet. 




5.2.6 Delay Accuracy Test 

Be sure that a Pulse Generator with at least 10 ppm frequency accuracy is used for this test. 

Pulse Generator 

Signal Generator 

Series 8500A 

Modulation 

Trigger 

Input 

RF Out 

Peak Power 

Sensor 

Figure 5-2. Delay Accuracy Test Setup 

1. Set the peak average value to 20 by pressing [MENU] (2) [F2] [20] [UNITS]. Set the internal 

delay for 75 µs by pressing [MENU] (9) [F2] [75] [µs]. 

2. Set the Pulse Generator to generate a 10 µs wide pulse with a repetition rate of exactly 10 kHz. 

Adjust the amplitude to 5 V. Connect the Pulse Generator to the RF source (Signal Generator) as 

shown in Figure 5-2. Set the Source to generate a 50 µs pulse when triggered by the Pulse 

Generator. Adjust the amplitude of the Source to 0 dBm or greater. The frequency of the Source 

is not important. Any Source operating within the range of the PPM will be satisfactory if it can 

be modulated with an external pulse signal and has a rise time less than about 30 ns. 

3. Set the PPM to read in the Graph Mode by pressing [GRAPH]. Press [GRAPH] again to cause 

the autoscale function to be performed after the PPM has been connected to the Pulse Generator. 

A graph of the pulse profile should now be displayed. 

4. Select a delay window of 0.2 µs and set the cursor delay to place the cursor at the 50% point on 

the rising edge of the pulse. Note the Cursor Delay Value. 

5. Press [MENU] (4) [F1]. Set the Reference Delay to be the value read at the 50% point of the 

first pulse (causing the cursor delay to be zero). 

6. Set the start delay to 99.90 µs. Set the cursor delay to place the cursor on the 50% point of the 

rising edge of the pulse. The cursor delay should read 100.00 µs ±0.01 µs. 




5.2.7 Analog Output Accuracy Test 

Set the RF Source to generate 0 dBm CW and connect the channel A detector to the output. Connect the 

DVM to the channel A analog output on the rear of the PPM and, using the procedure in step 1 of the 

Power Linearity Test, set the PPM to read CW with an averaging factor of 900. Perform the following 

steps: 

1. Adjust the RF Source so that the PPM reads exactly 0.00 dBm. Record the reading of the DVM. 

It should be less than 10 mV. 

2. Adjust the RF Source so that the PPM reads exactly -10.00 dBm. Subtract the DVM reading 

recorded in Step 1 from the current reading. The magnitude of the difference should be 

1.000V ±5 mV. 

3. If a Model 8502A is being tested, repeat Steps 1 and 2 after moving the DVM to the channel B 

analog output. 

5.2.8 Voltage Proportional to Frequency Test 

Press [MENU] (3) [F3] to choose the source of frequency correction. Then press [F2] to select the rear 

panel input. The input characteristics will then be specified as follows: 

Voltage/GHz = 1.00 

Sweeper Start Voltage = 0.000 

Sweeper Start Frequency = 0.000 

Adjust the Precision DC Source to 0.00 V and connect it to the frequency input on the rear panel of the 

PPM. Select the CW Mode display. The FREQ readout at the bottom of the display should read 

0.000 GHz. Set the Precision DC Source to exactly 10.00 V. The display should read 

10.000 GHz ±0.050 GHz. 

5.2.9 Detector Return Loss Test 

Use the 8003 or another return loss test setup appropriate to the frequency range of the detectors to be 

used with the PPM. Measure the return loss of the detector(s) used with the PPM. Specifications depend 

on the type of detector, its frequency range, and the type of connector being used. Refer to Appendix D 

to determine the specifications for the particular detector under test. When using this equipment, be sure 

to allow for the bridge directivity contribution to measurement uncertainty (in dB); this must be 

subtracted from the value of return loss specified for the detector. 

5.2.10 Plotter Output/IEEE-488 Interface 

Connect the signal generator to the PPM and display a pulse waveform in the Graph Mode. The pulse 

parameters, frequency, etc. are arbitrary for the purposes of testing the GPIB plot output of the PPM. 

1. Use an IEEE-488 cable to connect the graphics plotter to the GPIB output connection on the rear 

panel of the PPM. Note the plotter address as selected on the plotter. 

2. Press [MENU] (6) [F2] to enter the plotter address. If the current address is different from the 

desired address, enter the correct address number. 

3. Press [MENU] (2) [F3] to begin the plot. 

This completes the Performance Verification Tests of the PPM. If the instrument performed as given in 

this procedure, it is correctly calibrated and within published specifications. 




5.3 Calibration Procedures 

Using all solid state components, the Model 8501A/8502A meters are extremely rugged and reliable. 

Consequently, there is very little drift due to component aging, and adjustments to the units are rarely 

required. If measurements indicate that an adjustment is set within the indicated range, do not attempt to 

make it exact. It is often the case that variations in the equipment being used to make the test account for 

small differences in measured values. Since some adjustments can be interactive, be absolutely sure that 

an adjustment is required before making it. 

These procedures should be performed whenever the instrument is due for routine calibration, or at any 

time calibration is required due to environmental or physical conditions. All test points and adjusting 

components are labeled and are accessible at the top of the PC boards. It is not necessary to remove any 

PC boards from the unit to perform these calibration procedures. 

Figure 5-3 is a reference locater for the various components required for adjusting purposes during the 

calibration procedure. 

If you need to calibrate any of the RF detectors used with the PPM (such as after replacing the diode 

element), you can do it in the field with the Giga-tronics PROM Programming Accessory Kit, P/N 16976. 

This kit contains all of the necessary components and instructions required for proper detector 

calibration. If the kit is not available, the detector can be returned to the factory for calibration. 




Figure 5-3. Model 8501A/8502A Calibration Components 




5.3.1 Calibration Equipment Required 

Test equipment required to calibrate the Models 8501A and 8502A power meters is listed in Table 5-2. 

Equivalent or similar test equipment can be substituted. 

Table 5-2. Required Calibration Test Equipment 


Digital Voltmeter (DVM) Fluke Model 8800 5 digit display, 0.01% accuracy 

Frequency Counter EIP Model 548 10 digit readout. At least 1 GHz 

Frequency Counter/Timer Tektronix Model DC509 30 µs period, 1 ppm 

Oscilloscope (Scope) Tektronix Model 465 5 mV/DIV & 50 MHz bandwidth 

Power Meter HP Model 432 0.95 to 1.05 GHz at 0 dBm, 1.3% 

Precision Voltage Source Digitec Model 3110 5.000V with 0.02% accuracy 

Pulsed RF Signal Generator Giga-tronics Model 907 Trig. Modulator 

Variac General Radio Model W5MT3A Metered 

RF Detector Giga-tronics Model 16936 High Speed (15 ns) 

5.3.2 Preset Conditions 

Before stating the calibration procedures, the PPM should be placed into a preset condition. The 

Information given in this chapter can be used to calibrate and/or confirm calibration of the PPM and its 

detector(s) using the built-in automatic detector calibration system. 

A. Frequency Counter/Timer 

1. Set FUNCTION switch to PERIOD A. 

2. Set AVERAGES switch to 10 to the 6th power. 

3. Set SLOPE switch to +. 

4. Set ATTEN switch to X1. 

5. Set SOURCE switch to EXT. 

6. Set COUPL switch to dc. 

7. Set TRIG LEVEL switch to AUTO. 

B. Signal Generator 

1. Select MODE - PM (Pulse Modulation). 

2. Select PULSE MODE - INT -PULSE. 

3. Select RATE (HZ) - 1K. 

4. Select PULSE DELAY - X1. 

5. Select PULSE WIDTH - X1. 

6. Adjust RATE to midway between MIN and MAX. 

7. Adjust DELAY to approx. 3 µs (minimum). 

8. Adjust WIDTH to a point midway between 0.2 µs and 10 µs (approx. 5 µs). 

9. Connect a cable from the SYNC NORMAL OUTPUT of the Signal Generator to the TRIG 

INPUT on the back of the PPM. 

10. Connect the PPM to the Variac, set the Variac to 115 Vac, and turn the power on. 




5.3.3 A2 Regulator Board 

A. +5 V Adjust 

1. Connect the DVM LO test lead to A2TP11. 

2. Connect the DVM HI test lead to A2TP9. 

3. Adjust A2R42 (+5V ADJ) for a DVM reading of +5.000V ±100 mV. 

4. Vary the Variac voltage from 100 Vac to 130 Vac. The DVM reading must not change more 

than ±5 mV. 

B. -5.2 V Check. 

1. Connect the DVM HI test lead to A2TP10. The DVM must read -5.200 V ±200 mV. 

2. Vary the Variac voltage from 100 to 130 Vac. The DVM reading must not change by more 

than ±5.2 mV. 

3. Set the Variac to 115 Vac. 

C. -15 V Adjust. 

1. Connect the DVM LO test lead to A2TP6. 

2. Connect the DVM HI test lead to A2TP5. 

3. Adjust A2R22 (-15 V ADJ) for a DVM reading of -15.000V ±15 mV. 

4. Vary the Variac voltage from 100 to 130 Vac. The DVM reading must not change by more 

than ±15 mV. 

D. +15 V Check. 

1. Connect the DVM HI test lead to A2TP3. The DVM must read +15.000 V ±45 mV. 

2. Vary the Variac voltage from 100 to 130 Vac. The DVM reading must not change by more than 

±15 mV. 

Turn OFF the power. 

Disconnect the Variac and connect the power meter to the ac power source. 




5.3.4 Initialization 

A. Turn the instrument on. 

The PPM will automatically perform a self-test. At the completion of the self-test, the PPM will 

return to the last setup before power down. If the self-test failed, note the failure number and proceed 

by pressing [CLEAR]. 

B. Calibrate the Detector. 

The following portion of the Calibrator procedure needs to be done only if the detector being used is 

different than the one that was last used with the PPM. 

1. Press [CLEAR]. 

2. Connect the detector to the Calibrator output (use channel A detector if the unit is an 8502A). 

3. Press [UNITS] and wait for the calibration cycle to complete. 

4. Disconnect the detector from the Calibrator output. 

5. If the unit is an 8502A and a channel B detector is connected, perform the following steps. 

a. Connect the channel B detector to the Calibrator output. 

b. Press [CLEAR] [UNITS] and wait for the calibration cycle to complete. 

c. Disconnect the detector from the Calibrator output. 

C. Set the Internal Clock 

The Internal Clock can be set as follows: 

1. Press [MENU] (5) [F3] [F1]. 

2. Enter the correct date ([mmddyy] [UNITS]). 

3. Enter the correct time ([hhmmss] [UNITS] [F3]). 

5.3.5 A8 Front Panel Interface Board 

A. Display Brightness Adjust 

1. Connect the DVM HI lead to A8TP9 (+HV). 

2. Connect the DVM LO lead to chassis. 

3. Read the VWrite+ voltage shown on the sticker located on the back of A10 (the back of the 

display). 

4. Adjust A8R33 until the DVM reads within ±1 V of VWrite+. The display should be of even 

brightness across the screen without any smearing. 

5. Disconnect the DVM leads. 




5.3.6 A6/A7 Analog Board 

Analog PC Board Nos. A6 and A7 are identical. The Model 8501A uses just the A6 board; the Model 

8502A uses both A6 and A7. When testing a Model 8502A, all A6 reference designations listed in 

this section will become A7 when the A7 board is tested. 

A. +10 V Reference Adjust 

1. Connect the DVM LO lead to A6TP1 (REF COMMON). 

2. Connect the DVM HI lead to A6TP2 (+10 V). 

3. Adjust A6R13 (10V REF ADJ) for 10.000V ±3 mV. 

4. If the unit is an 8502A, repeat Steps 1 through 3 for the A7 Analog board. 

5. Disconnect the DVM. 

B. Sampler Zero Adjust. 

1. Set the Peak Averaging Number to 20 by pressing [MENU] (2) [F2] [20] [UNITS] 

2. Connect the sync output from the back of the PPM to the Ext Trig IN on the scope, the Scope HI 

lead to A6TP5, and the scope ground lead to A6TP11. 

3. Set the pulse generator to generate a 10 µs wide pulse with repetition rate of 1 kHz and 

amplitude at 5 V (TTL). Connect the pulse generator to the TRIG INPUT (TTL) on the rear 

panel of the PPM. 

4. Press [PEAK] [MENU] [F2]. 

5. Adjust A6R112 (SAMPLER ZERO) for 0V ±2 mV offset at the end of the sample time. 

C. Trigger Offset Adjust. 

1. Set the trigger to channel A, Internal, -15 dBm by pressing [MENU] (1) [F1] (channel A if unit 

is an 8502A) [-15] [dBm]. 

2. Connect the DVM HI lead to A6TP13 (TRIGGER OFFSET). 

3. Adjust A6R113 (TRIG OUT DC OFFSET) for 0V ±1 mV offset. 

4. If the unit is an 8502A, repeat Steps B and C for board A7. 

5. Disconnect the DVM test leads. 

D. Analog Output Adjust. 

1. Press the RESET button on the back of the PPM. 

2. Press [MENU] (11) [F1] [1] [F2]. 

☛ NOTE: If the PPM required detector calibration when the PPM prompts CONNECT 

DETECTOR TO CALIBRATOR, THEN PRESS ANY UNITS KEY, press [7] to access the 

service functions. 

3. Connect a cable from the DVM to the ANALOG OUTPUT on the back of the PPM (ANALOG A 

output if the unit is an 8502). 

4. Adjust A6R47 (LIN GAIN) for 0.000V ±10 mV reading on the DVM. 

5. Press [F3]. 

6. The DVM should read 3.000V ±25 mV. 




7. Press [F1]. 

8. The DVM should read -5.000 V ±35 mV. 

9. If the unit being tested is an 8502A, press [F2] and repeat Steps 3 through 8 after moving the 

rear cable to the ANALOG B output. 

E. Thermistor Sense Circuit. 

1. Press [CLEAR] [4] [F1] 

2. The reading should be approximately 5000 mV at a detector temperature of 30 °C (82.4 °F). The 

reading will vary about ±0.2 V/°C with any increase or decrease in temperature from the 30 °C 

level (a new reading is taken each time F1 is pressed.) 

3. Press [CLEAR] [CLEAR]. 




5.3.7 A3 GPIB/CAL Control Board 

CAUTION 

The maximum output power of the Calibrator is over 100 mW. Be sure it is working 

properly before connecting the power meter. 

A. Calibrator Frequency Check. 

1. Connect the Frequency Counter to the PPM Calibrator output. 

2. Select Calibrator TEST MODE by pressing [MENU] [F3] [F1] [7]. 

3. The frequency must be 1 GHz ±50 MHz. 

4. Disconnect the Frequency Counter from the Calibrator output. 


B. Calibrator Output Adjust. 

1. Zero the Power Meter. 

2. Connect the Power Meter detector to the Calibrator output on the PPM and press [7]. 

3. Adjust A3R16 (CALIB SET) for 0 dBm. 

a. Press any numeric key. If the power meter indication is negative (e.g. -0.2 dBm), adjust 

A3R16 clockwise to approximately twice the error. 

b. Press any of the numeric keys to take a reading. 

c. Repeat Steps a and b until the power meter reads 0.00 dBm. 

4. Disconnect the detector from the PPM. 


C. Power Meter Calibrate. 

1. Connect the Detector to the Calibrator output (use channel A if the unit is an 8502A). 

2. Press [UNITS]. 

3. Wait for the PPM to calibrate itself (about 1 minute). 

4. Disconnect the detector from the Calibrator output. 

5. If the unit is an 8502A, repeat Steps 1 through 4 for channel B. 

5.3.8 A4 CPU Board 

A. Time Oscillator Adjust. 

1. Connect the Frequency Counter/Timer common lead to A4TP3 (COMMON). 

2. Connect the Frequency Counter/Timer test lead to A4TP6. 

3. Adjust A4C47 for 30.517578 µs ±0.000100 µs. 

4. Disconnect the Frequency Counter/Timer test leads. 




5.3.9 A5 Digital Delay Board 

A. Delay Oscillator Adjust. 

1. Connect the Frequency Counter common lead to A5TP3 (5 V common) 

2. Connect the Frequency Counter test lead to A5TP5. 

3. Adjust A5C79 for 39.062500 MHz ±100 Hz. 

4. Disconnect the Frequency Counter test lead. 

B. Vernier Delay Adjust. 

☛ NOTE: This adjustment requires the use of the high speed (15 ns) detector. Do not attempt 

it with a low speed (750 ns) detector. 

1. Connect the detector to the signal generator (use channel A if the unit is a 8502A). 

2. Place the PPM in the Graph mode by pressing [GRAPH]. 

The left half of the PPM display should look similar to Figure 5-4. Each of the division marks at 

the bottom of the display represent 1/10th of the total display window. The left edge of the 

display is equal to the Start Delay, and the right edge is equal to the Delay Window plus the 

Start Delay. The division marks on the left side of the display represent the 10%, 50%, 90% and 

100% Reference Power levels. 

Figure 5-4. Typical PPM Digital Delay Display 

3. Select External Trigger by pressing [MENU] [F2]. 

4. Adjust the Start Delay to move the start of the pulse near the beginning of the graphics display. 

a. Move the cursor to the STRT DLY line. 

b. Rotate the spin knob clockwise until the start of the pulse is within 1/4 of a division of the 

start of the graphics display. Press [UNITS]. 

5. Adjust the Delay Window to 0.05 µs by moving the cursor to DLY WIND, entering 0.05 through 

the keypad, and then pressing [µs]. 

6. Set the Cursor Delay to the 25.6 ns multiple (see Table 5-3) that occurs after the start of the 

displayed pulse by moving the cursor to CRS DLY, entering the multiple value, and then pressing 

[ns] or [µs]. 




7. Set the Start Delay to the value in the column to the right of the 26.5 ns that was selected in Step 

6 above by moving the cursor to STRT DLY, entering the number (e.g. 0.0196 which is 0.0256 

minus 0.006), and then pressing [µs]. 

8. Set the Pulse Delay on the Signal Generator so that the rising edge of the pulse on the PPM 

display crosses through the cursor at approximately the input pulse 50% point. 

9. Set the Delay Window for 12 ns by moving the cursor to DLY WIND, entering [12], and 

pressing [ns]. 

10. Set the Reference Power. Move the cursor to the REF PWR line and press [UNITS]. 

11. Adjust A5R30 (Vernier Delay) to its maximum ccw position. 

12. The display should look similar to Figure 5-5. 

Figure 5-5. Typical PPM Display with A5R30 at Max cw 

13. Adjust A5R30 ccw until the rise time of the displayed pulse is smooth (see Figure 5-6). 

14. Set the peak averaging number to 50 by pressing [MENU] (2) [F2] [50] [UNITS]. 

15. The rising slope of the pulse must still look smooth. If not, readjust A5R30. 

16. Press [GRAPH]. 

Figure 5-6. Typical PPM Display w/Smooth Rise Time 




Table 5-3. Multiples of 25.6 ns 

Cursor Delay 

(ns) 

Start Delay 

(ns) 

Cursor Delay 

(ns) 

Start Delay 

(ns) 

Cursor Delay 

(ns) 

Start Delay 

(ns) 

Cursor Delay 

(ns) 

Start Delay 

(ns) 

25.60 19.60 1.0240 1.0180 2.0224 2.0164 3.0208 3.0148 

51.20 45.20 1.0496 1.0436 2.0480 2.0420 3.0464 3.0404 

76.80 70.80 1.0752 1.0692 2.0736 2.0676 3.0720 3.0660 

102.40 96.40 1.1008 1.0948 2.0992 2.0932 3.0976 3.0916 

128.00 122.00 1.1264 1.1204 2.1248 2.1188 3.1232 3.1172 

153.60 147.60 1.1520 1.1460 2.1504 2.1444 3.1488 3.1428 

179.20 173.20 1.1776 1.1716 2.1760 2.1700 3.1744 3.1684 

204.80 198.80 1.2032 1.1972 2.2016 2.1956 3.2000 3.1940 

230.40 224.40 1.2288 1.2228 2.2272 2.2212 3.2256 3.2196 

256.00 250.00 1.2544 1.2484 2.2528 2.2468 3.2512 3.2452 

281.60 275.60 1.2800 1.2740 2.2784 2.2724 3.2768 3.2708 

307.20 301.20 1.3056 1.2996 2.3040 2.2980 3.3024 3.2964 

332.80 326.80 1.3312 1.3252 2.3296 2.3236 3.3280 3.3220 

358.40 352.40 1.3568 1.3508 2.3552 2.3492 3.3536 3.3476 

384.00 378.00 1.3824 1.3764 2.3808 2.3748 3.3792 3.3732 

409.60 403.60 1.4080 1.4020 2.4064 2.4004 3.4048 3.3988 

435.20 429.20 1.4336 1.4276 2.4320 2.4260 3.4304 3.4244 

460.80 454.80 1.4592 1.4532 2.4576 2.4516 3.4560 3.4500 

486.40 480.40 1.4848 1.4788 2.4832 2.4772 3.4816 3.4756 

512.00 506.00 1.5104 1.5044 2.5088 2.5028 3.5072 3.5012 

537.60 531.60 1.5360 1.5300 2.5344 2.5284 3.5328 3.5268 

563.20 557.20 1.5616 1.5556 2.5600 2.5540 3.5584 3.5524 

588.80 582.80 1.5872 1.5812 2.5856 2.5796 3.5840 3.5780 

614.40 608.40 1.6128 1.6068 2.6112 2.6052 3.6096 3.6036 

640.00 634.00 1.6384 1.6324 2.6368 2.6308 3.6352 3.6292 

665.60 659.60 1.6640 1.6580 2.6624 2.6564 3.6608 3.6548 

691.20 685.20 1.6896 1.6836 2.6880 2.6820 3.6864 3.6804 

716.80 710.80 1.7152 1.7092 2.7136 2.7076 3.7120 3.7060 

742.40 736.40 1.7408 1.7348 2.7392 2.7332 3.7376 3.7316 

768.00 762.00 1.7664 1.7604 2.7648 2.7588 3.7632 3.7572 

793.60 787.60 1.7920 1.7860 2.7904 2.7844 3.7888 3.7828 

819.20 813.20 1.8176 1.8116 2.8160 2.8100 3.8144 3.8084 

844.80 838.80 1.8432 1.8372 2.8416 2.8356 3.8400 3.8340 

870.40 864.40 1.8688 1.8628 2.8672 2.8612 3.8656 3.8596 

896.00 890.00 1.8944 1.8884 2.8928 2.8868 3.8912 3.8852 

921.60 915.60 1.9200 1.9140 2.9184 2.9124 3.9168 3.9108 

947.20 941.20 1.9456 1.9396 2.9440 2.9380 3.9424 3.9364 

972.80 966.80 1.9712 1.9652 2.9696 2.9636 3.9680 3.9620 

998.40 992.40 1.9968 1.9908 2.9952 2.9892 3.9936 3.9876 




5.3.10 External Interface 

A. Monitor Outputs. 

1. Connect a terminated coaxial cable from the MONITOR output on the back of the PPM to the 

Scope (channel A if the unit is an 8502A). 

2. The Scope display should look like the pulse displayed on the PPM Graphics display with the 

amplitude representing the buffered detector signal. 

3. If the unit being tested is an 8502A: 

a. Disconnect the channel A detector from the Signal Generator. 

b. Connect the channel B detector to the Signal Generator. 

c. Select B channel AUTOSCALE by pressing [B] [GRAPH]. 

d. Move the coaxial cable from the A channel MONITOR output to the B channel MONITOR 

output on the 8502A. 

e. The Scope display should be the same as Step 2. 

4. Disconnect the terminated coaxial cable from both the 8502A and the Scope. 

B. Sync Output. 

1. Connect a coaxial cable (no termination) from the SYNC output on the back of the PPM to the 

Scope. 

2. The Scope display should be similar to Figure 5-7. 

-0.8V 

-1.8V 

20 ns 

Figure 5-7. Typical PPM Sync Output Scope Display 

3. Disconnect the coaxial cable from both the PPM and the Scope. 

C. Frequency Input. 

1. Connect a coaxial cable from the voltage source to the FREQUENCY INPUT connection on the 

back of the PPM. 

2. Set the voltage source to +5.000V. 

3. Select the External Frequency input by pressing [MENU] (3) [F3] [F2] [UNITS] [UNITS] [GHz] 




4. Place the system into the Peak Mode by pressing [PEAK]. 

5. The FREQ = XXXX portion of the PPM display must read 5.000 GHz ±0.020 GHz. 

D. RF Blanking Output. 

1. Connect a coaxial cable from the Scope to the RF BLANKING output on the PPM. 

2. Disconnect the Detector from the Signal Generator. 

3. The Scope should display a dc level of +5 V. 

4. Enter the Autozero function by pressing [MENU] [F3] [F2] [UNITS]. 

5. During the Autozero cycle the Scope display must drop to near 0 V, and then return back to +5 V. 

5.3.11 Volume Adjust 

1. Adjust the VOLUME ADJ on the back of the PPM fully ccw. 

2. Press several keys. Very little (if any) sound (clicks) should be heard from the speaker when the 

keys are pressed. 

3. Adjust the VOLUME ADJ fully clockwise. 

4. Press several keys. The clicks should be very easy to hear when the keys are pressed. 

The volume of the beeps used to indicate success or failure of zeroing, calibration, and self-test will be 

set to the same level as the adjustment for the clicks. 



Giga-tronics Series 8500A 

Performance Verification Test Data Sheet 

Make copies of this Data Sheet and use the copies for recordings. While proceeding through the 

Calibration procedures, if any specification cannot be met by performing the given adjustments, go 

immediately to Troubleshooting in Chapter 6 and follow the procedures to identify the problem. 

Date: 

Operator: 

Model 8501A or 8502A S/N: 

Test Number: (if required: 

CW Linearity Data 

Step 

Attenuator 

Value 

Power 

Set Point 


Meter 

Reading 

(P) 

8540C 

(DUT) 

Reading 

(R) 

Reference 


Ratio 

Reading 

Ratio 

Linearity Error (%) 1 

Linearity 

Specification 

Accumulated 

Linearity 

Error 2 

0 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

P1 = P1/P2 = R1/R2 = 

P2 = ±4% Same as Lin. 

error above 

10 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±4% 

20 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±4% 

30 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±4% 

40 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±5% 

50 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±14% 

1. Linearity Error (%) = [(R1/R2) / (P1/P2) - 1] * 100 

2. Accumulated error is the sum of the current dB segment linearity error plus the previous accumulated error. 



Peak Power Linearity Data 

Step 

Attenuator 

Value 


Set Point 


Meter 

Reading 

(P) 

8540C 

(DUT) 

Reading 

(R) 

Reference 


Ratio 

Reading 

Ratio 

Linearity Error (%) 1 

Linearity 

Specification 

Accumulated 

Linearity 

Error 2 

0 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

10 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

20 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

30 dB 10.00 mW 

±0.25 mW 

1.00 mW 

±0.025 mW 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±4% 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±4% 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±7% 

P1 = R1 = P1/P2 = R1/R2 = 

P2 = R2 = ±39% 

3. Linearity Error (%) = [(R1/R2) / (P1/P2) - 1] * 100 

4. Accumulated error is the sum of the current dB segment linearity error plus the previous accumulated error. 

Other Test Results 

(Listed in the same order as given in the performance test) 

Test See Section Specifications Reading 

Calibration Output Level 5.2.3 0.995 to 1.045 mW 

Delay Accuracy 5.2.6 799.92 to 800.08 µs 

Analog Output Accuracy 5.2.7 0.995 to 1.005 V 

V prop F Test 5.2.8 9.95 to 10.05 GHz 




Giga-tronics Series 8500A 

Calibration Data Recording Sheet 

Make copies of this Data Sheet and use the copies for recordings. While proceeding through the 

Calibration procedures, if any specification cannot be met by performing the given adjustments, go 

immediately to Troubleshooting in Chapter 6 and follow the procedures to identify the problem. 

Date: 

Operator: 

Temperature: 

Model and Serial No: 

Test Number (if required): 

Humidity: 

Manual Section Section Step Specification Reading 

Regulator Board 5.3.3 A.3 +4.900 V to +5.100 V 

5.3.3 A.4 Within 5 mV of A.3 reading 

5.3.3 B.1 -5.000 V to -5.400 V 

5.3.3 B.2 Within 5.2 mV of B.1 reading 

5.3.3 C.3 -14.985 V to -15.015 V 

5.3.3 C.4 Within 15 mV of C.3 reading 

5.3.3 D.1 +14.995 V to +15.045 V 

5.3.3 D.2 Within 15 mV of D.1 reading 

A6 

A7 (8502A Only) 

Analog Board 5.3.6 A.3 +9.997 V to +10.003 V 

5.3.6 B.5 -2 mV to +2 mV 

5.3.6 C.3 -1 mV to +1 mV 

5.3.6 D.4 -10 mV to +10 mV 

5.3.6 D.6 +2.975 V to +3.025 V 

5.3.6 D.8 -4.965 V to -5.035 V 

5.3.6 E.2 Approx. 5000 mV 

(±0.2 V/°C dev. from 30 °C) 

GPIB/Cal Ctrl 

Board 

5.3.7 A.3 950 to 1050 MHz 

CPU Board 5.3.8 A.3 30.517478 to 30.517678 µs 

Digital Delay 

Board 

5.3.9 A.3 39.062400 to 39.062600 MHz 

Ext. Interface 5.3.10 C.5 4.98 to 5.02 GHz 

5.3.10 D.3 +5 Vdc 

5.3.10 D.5 Approx. 0 Vdc 






6 

Maintenance 


This chapter defines maintenance practices and troubleshooting procedures required for fault isolation 

down to PC board level. 

Problems can occur that might be produced by equipment or components peripheral to the 8501A/8502A 

units. Preliminary checks should be made to be sure that a malfunction of external equipment or 

components is not causing what appears to be a problem within the instrument. 

6.2 Periodic Maintenance 

The following maintenance procedures should be performed once each year unless the meter is operated 

in an extremely dirty or chemically contaminated environment. More frequent periodic maintenance may 

then required. 

1. Blow out all accumulated dust and dirt with forced air under moderate pressure. Also, the air 

filter for the cooling fan on the rear panel of the PPM should be checked every 3 months for 

accumulated dust. A dirty filter can restrict air flow into the unit and cause the instrument to 

overheat, which may cause the thermal sensor to shut the instrument off in the middle of a test 

routine. If dirty, the filter should be removed and cleaned with a mild detergent and water 

solution. Replacement filters can be ordered from the factory. 

2. Remove the filter from its holder by snapping the retainer out of the holder. Do not remove the 

screws from the filter holder. 

3. Inspect the unit for loose wires or damaged components. Check that the PC boards are properly 

seated in their receptacles, and that all wire connectors are properly attached to their PC board 

pins. 

4. The front panel and housing of the unit can be cleaned with a cloth dampened in a mild 

detergent. Do not use abrasive cleaners, scouring powders, or any harsh chemicals. Wipe the soap 

residue off with a clean, damp cloth, then dry with a clean dry cloth. 

5. If calibration is required, refer to Chapter 5 of this manual for procedures. 

6. Make a performance verification test in accordance with the procedures in Chapter 5. If the 

performance is within the required specifications, no further service is necessary. 




6.2.1 Required Test Equipment 

The following test equipment is required to perform these procedures. Equivalent models and types can 

be substituted. 

Table 6-1. Required Test Equipment 


Digital Voltmeter (DVM) Fluke Model 8800 5 digit display, 0.01% accuracy 

Frequency Counter EIP Model 548 10 digit readout. At least 1 GHz 

Frequency Counter/Timer Tektronix Model DC509 30 µs period, 1 ppm 

Oscilloscope (Scope) Tektronix Model 465 5 mV/DIV & 50 MHz bandwidth 

Power Meter Giga-tronics Series 8540 0.95 to 1.05 GHz at 0 dBm, 1.3% 

Precision Voltage Source Digitec Model 3110 5.000 V with 0.02% accuracy 

Pulsed RF Signal Generator Giga-tronics Model 907 Trig. Modulator 

Variac General Radio Model W5MT3A Metered 

RF Detector Giga-tronics Model 16936 High Speed (15 ns) 



Maintenance 

6.3 Troubleshooting 

The information in this section should enable a technician to locate a malfunction and determine 

specifically which PC board is causing the problem. The instructions given in this section trace a problem 

to a specific board. Then, the electrical description of the board contained in Chapter 5 and the applicable 

diagram in Chapter 8 can be employed to assist the technician in circuit tracing the suspected board. 

Ensure that devices or components external to the PPM are not the cause of the problem before starting 

the Troubleshooting procedure. 

In general, troubleshooting of the PPM is divided into three parts. First, the display is observed for any 

error flags (numbers) that might pinpoint the specific faulty section of the circuitry (after performing the 

self-test function). Second, a known and specific pulse or CW signal is applied and varied as required to 

allow a general determination of the severity and parameters of the problem. Third, suspect PC boards are 

placed on extenders, and waveform and dc voltage indications are traced and checked. By following the 

initial approach, the steps in this section can help to isolate and locate the PC board causing a particular 

problem. 

6.3.1 Equipment Required 

The equipment in Table 6-1 is also required for the Troubleshooting procedures in this section. 

Additionally, the Giga-tronics Extender board (P/N 17075) or equivalent is needed for troubleshooting the 

A2 Power Supply PC board, and the Giga-tronics Extender board (P/N 17076) or equivalent is required 

for troubleshooting the A3 GPIB/Cal, A4 CPU, A5 Digital Delay, and A6/A7 Analog PC boards to 

component level. 

6.3.2 Power-On Failure 

1. No indication that the power is turned on when the ON button is pressed (fan not running and no 

lights on the front panel.) 

a. Ensure that the power cord is plugged into an ac source with the correct voltage and 

frequency for the PPM. (See Power Requirements in Section 2.2 of this manual.) 

b. Check the ac input fuse (F1) on the rear panel to be sure that it is in place and not blown. 

c. Ensure that the ac Select Plate is installed in the rear of the instrument. 

d. Ensure that the A2 Power Supply Regulator PC board is properly seated in its socket. 

e. Check the thermal shut-off switch located on board A2. (Also, see step 1 of Section 6.2) 

f. Check the 5 V (CR1) and 15 V (A1CR1) Bridge Rectifiers. 

2. Front panel apparently works (the display turns on and lights flash when power is applied), but 

the fan is not running. 

a. Check the 15 V supplies. 

b. Check the fan motor. 

c. Check the Fan Filter Circuit consisting of A1R1 through A1R4, A1C13, and A1C14. 

3. Fan is running, but nothing on the front panel is working. 

a. Check the +5 V and -5.2 V power supplies. 

b. Ensure that the A8 Front Panel Interface PC board is properly seated in its socket. 

4. Front panel lights are flashing and the display is dark. 

a. Ensure that the A4 CPU PC board is properly seated in its socket. 




b. Press [RESET] on the rear panel. If this clears the problem, check the output of the Reset 

Timer (A4U17) for a pulse width of approximately 750 ms when the RESET button is 

pressed. 

c. Check the 6 MHz CPU clock at A4TP1. 

d. Check the CPU Halt signal at A4U12, pin 17 (low digital level = a Halt condition). 

e. Check the Address and Data I/O on the CPU at A4U12. 

f. Check the Address Buffers on the CPU at A4U7, A4U8, and A4U9. 

g. Check the Data Buffers on the CPU at A4U32 and A4U33. 

h. Check the Address Decoder on the CPU at A4U34. 

i. Ensure that all of the PROMs on the CPU board are installed in their proper locations. 

Self-test Failure Indications & Possible Causes 

Information given in this section assumes that the PPM was working properly when it was initially turned 

on, that self-test was selected, a failure occurred, and an Error Number was shown in the instrument’s 

display window. Note that during the self-test, all of the front panel LEDs are lit. 

Each of the self-test checks will be described briefly, and then possible causes of the problem (as 

indicated by the displayed Error Number pertaining to the specific test) will be listed. 

Self-Test #1 (Error Number 01): -5.2 V Out of Tolerance 

This test applies -5.2 V to the Analog A/D Converter (A6U7) through switch A6U13. The -5.2 V must be 

between -4.94 and -5.46 V. 

1. Check the -5.2 V regulator circuit on PC board A2. 

2. Check the switches (A6U13C and A6U20) on the A6 Analog board. 

3. Check the PPI chip (A6U1). 

Self-Test #2 (Error Number 02): Memory Bad 

This test performs a walking 1’s test on the volatile RAM. (Clears the memory, then writes and reads a 1 

to each memory location. Then writes and reads a 2, etc.) 

Check the volatile RAM chips A4U5, A4U6, A4U30, and A4U31. 

Self-Test #3 (Error Number 03): Excessive A Channel Offset 

This test sets the A channel on the A6 Analog PC board to its maximum gain of 8192, and measures the 

total offset voltage present at the input to the Analog A/D Converter (A6U7). The allowable range for the 

voltage at the input to the Analog PC board is 0.5 mV which would mean a range of 4.096 V at the input 

to the A/D Converter. 

1. Swap the detector and run the self-test again. 

2. Check the amplifiers in the Analog PC board. 

3. Check the Analog Switches A6U25, A6U20, A6U15, and A6U13. 

4. Check the PPI chip A6U1. 

Self-Test #4 (Error Number 04): A Channel Gain Error 

The self-test sets the first variable gain stage to a gain of 8 and measures the offset. Then, 0.5 V is 

applied to the input of the x2 amplifier and the overall gain is measured. The first variable gain stage is 



Maintenance 

then reset to unity gain, and the second stage is tested, then the third, and then the fourth in the same 

way. The tolerance for each stage is 2% of the gain. 

1. Check the amplifiers in the Analog PC board. 

2. Check the Analog Switches A6U22, A6U15, and A6U13. 


Self-Test #5 (Error Number 05): Excessive B Channel Offset 

Use the same description and Troubleshooting procedures as given in Self-Test #3. All reference 

designations are changed to A7. Applies only to the Model 8502A. 

Self-Test #6 (Error Number 06): B Channel Gain Error 

Use the same description and Troubleshooting procedures as given in Self-Test #4. All reference 

designations are changed to A7. Applies only to the Model 8502A. 

Self-Test #7 (Error Number 07): A Channel Analog Output DAC 

This test routes the output of the Analog Output DAC circuit to the input of the Analog A/D Converter. 

The DAC is stepped through 81 steps from low to high (each step is 0.1 V). The tolerance is 

0.5% ±10 mV. 

1. A6R47 (LIN GAIN) is not adjusted properly. See Section 5.3.6. 

2. Check DAC circuit A6U8, A6U14A, and A6U21A. 

3. Check analog switches A6U20 and A6U13C. 


5. Check the decoder circuit consisting of A6U2C & D, A6U3C, and A6U5D. 

Self-Test #8 (Error Number 08): B Channel Analog Output DAC 

Use the same description and Troubleshooting procedures as given in Self-Test #7, preceding. All 

reference designations are changed to A7. Applies only to the Model 8502A. 

Self-Test #9 (Error Number 09): Delay 8255s 

This test writes a hex AA to the first port of A5U6 and reads back the data. It then writes a hex 55 to the 

same port and reads back the data. These tests are then performed on the remaining two ports of A5U6, 

and on all three ports of A5U7. 

1. Check A5U6 and A5U7. 

2. Check A5U4. 

3. Check Address Decoder A4U34. 

Self-Test #10 (Error Number 10): Delay Time Error 

This test sets the PPM into the Peak Mode with a delay of 200 ms. It then triggers the delay circuit and 

measures the time until the delay is complete. The tolerance is 7 ms. 

Make a thorough check of all circuits on the A5 Digital Delay PC board. 




Self-Test #11 (Error Number 11): Calibrator Bridge Voltage Error 

This test uses the same software as the Calibration cycle to check the bridge voltage. 

1. Check A3TP9. Must be between +3 and +10 Vdc. 

2. Check PPI chip A3U9. 

3. Check A3U14, A3U15, A3U10, A3U13, and A3U18A. 

4. Check the Calibrator (A12). 

5. Check Address Decoder A4U34. 

Input/Output & Calibration Failures 

1. The External Trigger input is not functioning. 

a. External Trigger not selected. See External Triggering in Section 2.6.2. 

b. Check A5Q1. 

c. Check A5U31 and A5U30. 

d. Check A5U7. 

2. The External Frequency input is not functioning. 

a. The External Frequency input has not been selected. See PROM Frequency Correction in 

Section 2.8.2. 

b. Check A6U20 (or A7U20 if this is a B channel problem). 

c. Check A6R81, A6R140, and A6C94. 

d. Check A6U1. 

3. The SYNC OUTPUT is not functioning. 

a. Check A5U35C. 

☛ NOTE: This is an ECL level pulse with a width of approximately 20 ns. 

4. The RF BLANKING OUTPUT is not functioning properly. 

a. Check A3Q7. 

b. Check A3U8. 

5. The MONITOR OUTPUT is not working. 

a. Check A6U30, A6U32 (or A7U30, A7U32 if it is a B channel problem). 

6. The PPM passes self-test, but fails when attempting to calibrate the detector. 

a. Replace the detector. 

b. Replace the detector cable. 

c. Refer to the GPIB/Cal control board instructions in Section 5.3.7 to check the Calibrator 

output. 



7 

Parts Lists 


This chapter contains the parts lists for all major and minor assemblies in the Series 8500A Peak Power 

Meters. Parts lists for available Options, when applicable, are in Appendix E under the respective option 

heading. A list of Manufacturers is included in Section 7.2. 

7.2 Parts Lists for Series 8500A Peak Power Meters 

If not otherwise specified, the following parts lists apply to both the Model 8501A and 8502A power 

meters. 

8501A PEAK POWER METER, Rev: C 

Item Part Number Qty Cage Mfr’s Part Number Description 

1 20512-A00 1 58900 20512-A00 8501A CHASSIS ASSY 

2 20508-001 1 58900 20508-001 FRONT PANEL, 8501A 

3 20790 1 58900 20790 OPER MANUAL KIT, 8500A SERIES 

4 HFFB-63201 2 21604 PP40013 REAR FOOT 

5 WMP0-03007 1 16428 17250 7.5’ IEC POWER CORD 

6 13592 2 58900 13592 RIGHT HANDLE CAP 

7 13593 2 58900 13593 LEFT HANDLE CAP 

8 HFBI-00014 1 21604 MP40008-10 14" INSIDE MOUNT BAIL 

9 15134-002 1 58900 15134-002 LABEL “A2" PER DWG 

10 15134-003 1 58900 15134-003 LABEL “A3" PER DWG 

11 15134-004 1 58900 15134-004 LABEL “A5" PER DWG 

12 15134-005 1 58900 15134-005 LABEL “A6" PER DWG 

13 15134-010 1 58900 15134-010 ID LABEL “ ”A4" 

14 15295 1 58900 15295 LABEL, BOTTOM DECK 

15 16536-003 2 58900 16536-003 HANDLE STRAP, 12.75" LG 

16 16956-001 1 58900 16956-001 8500 SERIES DET EXT CABLE 1.5M 

17 16957 1 58900 16957 TOP COVER 

18 16958 1 58900 16958 BOTTOM COVER 

19 17018 1 58900 17018 RIVETED PS COVER ASSY 

20 17028-001 8 58900 17028-001 SCR TRUSS HD 4-40X.25 LT GREY 

21 17324-001 1 58900 17324-001 HOLDDOWN, PCB 8501A 

22 19975-003 1 58900 19975-003 SHIPPING BOX, 275# DW 30x24x12 

23 20601 1 58900 20601 FILTER, EL DISPLAY 

24 20602 1 ——- 20602 BEZEL, EL DISPLAY 

25 20635 1 58900 20635 SHIELD, HIGH VOLTAGE 

26 20636 1 0ABX4 20636 LABEL, WARNING 

27 20738 1 58900 20738 DIE CUT TRANSFER TAPE, DISPLAY 

28 21098 1 58900 21098 KNOB, 48mm - .25 COLLET 

29 HFFL-63202 1 21604 1S001201 LEFT FRONT FOOT 

30 HFFR-63202 1 21604 1S001202 RIGHT FRONT FOOT 

31 70112 REF 58900 70112 PROCEDURE, MODEL 8501A 




8502A DUAL INPUT PEAK POWER METER, Rev: C 


1 20513-A00 1 58900 20513-A00 8502A CHASSIS ASSY 

2 20510-001 1 58900 20510-001 FRONT PANEL, 8502A 

3 HFFB-63201 2 21604 PP40013 REAR FOOT 

4 WMP0-03007 1 16428 17250 7.5’ IEC POWER CORD 

5 13592 2 58900 13592 RIGHT HANDLE CAP 

6 13593 2 58900 13593 LEFT HANDLE CAP 

7 HFBI-00014 1 21604 MP40008-10 14" INSIDE MOUNT BAIL 

8 15134-002 1 58900 15134-002 LABEL “A2" PER DWG 

9 15134-003 1 58900 15134-003 LABEL “A3" PER DWG 

10 15134-004 1 58900 15134-004 LABEL “A5" PER DWG 

11 15134-005 1 58900 15134-005 LABEL “A6" PER DWG 

12 15134-010 1 58900 15134-010 ID LABEL “ ”A4" 

13 15295 1 58900 15295 LABEL, BOTTOM DECK 

14 16536-003 2 58900 16536-003 HANDLE STRAP, 12.75" LG 

15 16956-001 2 58900 16956-001 8500 SERIES DET EXT CABLE 1.5M 

16 16957 1 58900 16957 TOP COVER 

17 16958 1 58900 16958 BOTTOM COVER 

18 17018 1 58900 17018 RIVETED PS COVER ASSY 

19 17027-001 8 58900 17027-001 SCR TRUSS HD 4-40X.25 MED GREY 

20 17028-001 8 58900 17028-001 SCR TRUSS HD 4-40X.25 LT GREY 

21 17325 1 58900 17325 HOLDDOWN, PCB 

22 19975-003 1 58900 19975-003 SHIPPING BOX, 275# DW 30x24x12 

23 20601 1 58900 20601 FILTER, EL DISPLAY 

24 20602 1 ——- 20602 BEZEL, EL DISPLAY 

25 20635 1 58900 20635 SHIELD, HIGH VOLTAGE 

26 20636 1 0ABX4 20636 LABEL, WARNING 

27 20738 1 58900 20738 DIE CUT TRANSFER TAPE, DISPLAY 

28 20790 1 58900 20790 OPER MANUAL KIT, 8500A SERIES 

29 21098 1 58900 21098 KNOB, 48mm - .25 COLLET 

30 HFFL-63202 1 21604 1S001201 LEFT FRONT FOOT 

31 HFFR-63202 1 21604 1S001202 RIGHT FRONT FOOT 




Parts Lists 

20512-A00 8501A CHASSIS ASSY, Rev: R 


1 10129 1 58900 10129 LABEL, CODE AND SERIAL NUMBER 

2 12701-004 1 58900 12701-004 GUIDE, 4.90" 

3 12701-012 1 58900 12701-012 GUIDE, 1.00" 

4 SPA0-00012 1 31918 FSC-BLACK BLACK BUTTON 

5 14913 1 58900 14913 LABEL, H.V. SHIELD 

6 HGP0-03000 11 32559 E-300 3" CARD GUIDE 

7 16869 1 58900 16869 DELAY LINE ASSEMBLY 

8 16949 1 58900 16949 LEFT CABINET SIDE 

9 16950 1 58900 16950 RIGHT CABINET SIDE 

10 16951 1 58900 16951 FRONT FRAME 8500 

11 16952 1 58900 16952 REAR FRAME 8500 

12 16953 1 58900 16953 BASE PLATE 

13 16954 1 58900 16954 LEFT PCB MTG BRACKET 

14 16955 1 58900 16955 RIGHT PCB MOUNTING BKT 

15 16964 1 58900 16964 AC SWITCH SHAFT 

16 16999 1 58900 16999 AC SWITCH COVER 

17 17012 1 58900 17012 POWER SUPPLY ENCLOSURE 

18 17217 4 58900 17217 RF SHIELD 

19 17218 8 58900 17218 INSULATOR, RF SHIELD 

20 17311 1 58900 17311 SUPPORT BRACKET, PCB 

21 20196 REF 58900 20196 SCHEMATIC, FRONT PNL INTERFACE 

22 20522 REF 58900 20522 SCHEMATIC 8501A & 8502A INSTR 

23 20527 REF 58900 20527 SCHEMATIC, FRONT PANEL 

24 XARC-00002 0 58900 XARC-00002 SILVER-FILLED RTV 

25 21118 1 58900 21118 LABEL, TESTED BY 


31 60334 REF 58900 60334 8500A CALIBRATION PROC 

27 60304 REF 58900 60304 8500A PRETEST PROC 

29 60348 REF 58900 60348 MODEL 850X/850XA SYS TEST PRO 

30 30019 REF 58900 30019 8500 & 8500A JIT FLOW CHART 

A1 16932-001 1 58900 16932-001 INTERCONNECT PCB ASSY 

A2 16995 1 58900 16995 PCB ASSY, POWER SUPPLY 

A3 21014 1 58900 21014 PCB ASSY GPIB/CAL CONTROL 8500 

A4 16878 1 58900 16878 PCB ASSY., CPU 

A5 16685 1 58900 16685 P.C. BRD. ASSY., DIGITAL DELAY 

A6 20741 1 58900 20741 ANALOG PCB ASSY 

A8 20195 1 58900 20195 PCB ASSY, FR PNL INTERFACE 

A12 20055-001 1 58900 20055-001 ASSY, 1GHZ CALIBRATOR TYPE N 

A13 21145 1 58900 21145 FRONT SUB PANEL ASSY 8501A 

A14 21146 1 58900 21146 REAR PANEL ASSY 8501A 

CR1 DBMC-00980 1 58900 DBMC-00980 MDA980-2 BRIDGE RECT 

LS1 ISS0-00001 1 58900 ISS0-00001 2" 8 OHM SPEAKER 

W7 17056 1 58900 17056 SPEAKER CABLE ASSY 

W9 17091-001 1 58900 17091-001 W9 W-R DISC CABLE ASSY 

W10 17163-001 1 58900 17163-001 W-PR DISC CABLE ASSY 




20513-A00 8502A CHASSIS ASSY, Rev: N 


1 10129 1 58900 10129 LABEL, CODE AND SERIAL NUMBER 

2 12701-004 2 58900 12701-004 GUIDE, 4.90" 

3 12701-012 1 58900 12701-012 GUIDE, 1.00" 

4 SPA0-00012 1 31918 FSC-BLACK BLACK BUTTON 

5 14913 1 58900 14913 LABEL, H.V. SHIELD 

6 HGP0-03000 13 32559 E-300 3" CARD GUIDE 

7 16869 2 58900 16869 DELAY LINE ASSEMBLY 

8 16949 1 58900 16949 LEFT CABINET SIDE 

9 16950 1 58900 16950 RIGHT CABINET SIDE 

10 16951 1 58900 16951 FRONT FRAME 8500 

11 16952 1 58900 16952 REAR FRAME 8500 

12 16953 1 58900 16953 BASE PLATE 

13 16954 1 58900 16954 LEFT PCB MTG BRACKET 

14 16955 1 58900 16955 RIGHT PCB MOUNTING BKT 

15 16964 1 58900 16964 AC SWITCH SHAFT 

16 16999 1 58900 16999 AC SWITCH COVER 

17 17012 1 58900 17012 POWER SUPPLY ENCLOSURE 

18 17217 5 58900 17217 RF SHIELD 

19 17218 10 58900 17218 INSULATOR, RF SHIELD 

20 17311 1 58900 17311 SUPPORT BRACKET, PCB 

21 20196 REF 58900 20196 SCHEMATIC, FRONT PNL INTERFACE 

22 20522 REF 58900 20522 SCHEMATIC 8501A & 8502A INSTR 

23 20527 REF 58900 20527 SCHEMATIC, FRONT PANEL 

24 XARC-00002 0 58900 XARC-00002 SILVER-FILLED RTV 

25 21118 1 58900 21118 LABEL, TESTED BY 


31 60334 REF 58900 60334 8500A CALIBRATION PROC 

27 60304 REF 58900 60304 8500A PRETEST PROC 

29 60348 REF 58900 60348 MODEL 850X/850XA SYS TEST PRO 

30 30019 REF 58900 30019 8500 & 8500A JIT FLOW CHART 

A1 16932-001 1 58900 16932-001 INTERCONNECT PCB ASSY 

A2 16995 1 58900 16995 PCB ASSY, POWER SUPPLY 

A3 21014 1 58900 21014 PCB ASSY GPIB/CAL CONTROL 8500 

A4 16878 1 58900 16878 PCB ASSY., CPU 

A5 16685 1 58900 16685 P.C. BRD. ASSY., DIGITAL DELAY 



A8 20195 1 58900 20195 PCB ASSY, FR PNL INTERFACE 

A12 20055-001 1 58900 20055-001 ASSY, 1GHZ CALIBRATOR TYPE N 

A13 21147 1 58900 21147 FRONT SUB PANEL ASSY 8502A 

A14 21148 1 58900 21148 REAR PANEL ASSY 8502A 

CR1 DBMC-00980 1 58900 DBMC-00980 MDA980-2 BRIDGE RECT 

LS1 ISS0-00001 1 58900 ISS0-00001 2" 8 OHM SPEAKER 

W7 17056 1 58900 17056 SPEAKER CABLE ASSY 

W9 17091-001 1 58900 17091-001 W9 W-R DISC CABLE ASSY 

W10 17163-001 1 58900 17163-001 W-PR DISC CABLE ASSY 



Parts Lists 

21145 FRONT SUB PANEL ASSY 8501A, Rev: A 


1 ETIM-02062 1 2R182 862 2 LUG TERMINAL STRIP 

2 HSTH-41104 12 06540 8217-46-B-0440-28 4-40 X 23/32 HEX SPACER 

3 14955-065 1 58900 14955-065 LABEL “TO A1J16" 

4 20509 1 58900 20509 FRONT SUB PANEL, 8501A 

5 20736 2 58900 20736 GUARD, FLAT CABLE 

6 20879 1 58900 20879 EL DISPLAY MODULE ASSEMBLY 

7 21039 1 58900 21039 BRKT, STRAIN RELIEF 

A9 20526-001 1 58900 20526-001 PC BOARD ASSY, FRONT PANEL 

B2 21100 1 58900 21100 ROTARY ENCODER ASSY 

C1 11573-001 1 3W023 CW15C102K CAP MIN CER .001MF 20% 50VDC 

W1 17051 1 58900 17051 DETECTOR INPUT CABLE ASSY 

W4 20570 1 58900 20570 CABLE ASSY, FR PANEL-INTCON 

W8 20721 1 ——- 20721 CABLE ASSY, EL DSPL-FP INTFC 

21147 FRONT SUB PANEL ASSY 8502A, Rev: A 




3 HSTH-41104 12 06540 8217-46-B-0440-28 4-40 X 23/32 HEX SPACER 

4 14955-065 1 58900 14955-065 LABEL “TO A1J16" 

5 14955-069 1 58900 14955-069 LABEL “TO A1J17" 

6 20511 1 58900 20511 FRONT SUB PANEL 8502A 

7 20736 2 58900 20736 GUARD, FLAT CABLE 

8 20879 1 58900 20879 EL DISPLAY MODULE ASSEMBLY 

9 21039 2 58900 21039 BRKT, STRAIN RELIEF 

A9 20526-002 1 58900 20526-002 PC BOARD ASSY, FRONT PANEL 

B2 21100 1 58900 21100 ROTARY ENCODER ASSY 




W4 20570 1 58900 20570 CABLE ASSY, FR PANEL-INTCON 

W8 20721 1 ——- 20721 CABLE ASSY, EL DSPL-FP INTFC 





21146 REAR PANEL ASSY 8501A, Rev: A 


1 17141 1 58900 17141 REAR PANEL 

2 HPM0-00687 2 57771 D3047 11/16 HOLE PLUG 

3 HPM0-00500 1 18310 790-3008 1/2 HOLE PLUG 

4 JIB0-01089 5 56501 RA-250 FEMALE QUICK DISCONNECT 

5 16966 1 58900 16966 AC SWITCH MTG BKT 

6 16973 4 58900 16973 INSULATING FLAT WASHER 

7 BHF0-13000 1 9Y422 FF325G 3" FAN FILTER 

8 17161 1 31918 51985 PLUNGER, EXTENDER 

9 19976 1 58900 19976 COVER PLATE, 8500 CALIBRATOR 

10 JLFL-01503 1 05245 JA413 2A 120V LABEL 

11 HPM0-00375 3 2R182 652 3/8 HOLE PLUG 

F1 FSAC-00200 1 ——- MDL-2 2A SB FUSE 3AG 

J1 JLFF-06250 1 05245 6J4 LINE FILTER/CONNEC 

J2 JRDF-00001 1 09769 31-221-RFX BNC F PANEL MOUNT 

J3 JRDF-00005 1 58900 JRDF-00005 BNC F PANEL MOUNT 




R2 RABA-01001 1 01121 WA1NO24S101MZ 100 OHM POT PANEL MOUNT 

S1 13260 1 2W053 001399 SWITCH PUSHBUTTON POWER 

T1 16762 1 58900 16762 TRANSFORMER PWR 

W2 17280 1 58900 17280 FAN ASSY 

W3 17131 1 58900 17131 REAR PANEL CABLE ASSY 8502 

W11 17259-001 1 58900 17259-001 BNC TO SMC RG178B/U CABLE ASSY 

21148 REAR PANEL ASSY 8502A, Rev: A 


1 HPM0-00687 2 57771 D3047 11/16 HOLE PLUG 

2 HPM0-00500 1 18310 790-3008 1/2 HOLE PLUG 

3 JIB0-01089 5 56501 RA-250 FEMALE QUICK DISCONNECT 

4 16966 1 58900 16966 AC SWITCH MTG BKT 

5 16973 4 58900 16973 INSULATING FLAT WASHER 

6 BHF0-13000 1 9Y422 FF325G 3" FAN FILTER 

7 17141 1 58900 17141 REAR PANEL 

8 17161 1 31918 51985 PLUNGER, EXTENDER 

9 19976 1 58900 19976 COVER PLATE, 8500 CALIBRATOR 

10 JLFL-01503 1 05245 JA413 2A 120V LABEL 

11 HPM0-00375 1 2R182 652 3/8 HOLE PLUG 

F1 FSAC-00200 1 ——- MDL-2 2A SB FUSE 3AG 

J1 JLFF-06250 1 05245 6J4 LINE FILTER/CONNEC 


J3 JRDF-00005 1 58900 JRDF-00005 BNC F PANEL MOUNT 






R2 RABA-01001 1 01121 WA1NO24S101MZ 100 OHM POT PANEL MOUNT 

S1 13260 1 2W053 001399 SWITCH PUSHBUTTON POWER 

T1 16762 1 58900 16762 TRANSFORMER PWR 

W2 17280 1 58900 17280 FAN ASSY 

W3 17131 1 58900 17131 REAR PANEL CABLE ASSY 8502 

W11 17259-001 1 58900 17259-001 BNC TO SMC RG178B/U CABLE ASSY 



Parts Lists 

20879 EL DISPLAY MODULE ASSEMBLY, Rev: D 


1 20879-A00 1 58900 20879-A00 EL DISPLAY MODULE SUB ASSY 

2 30086 REF 58900 30086 PRELIM TP FOR EL DISPLAY 

20879-A00 EL DISPLAY MODULE SUB ASSY, Rev: D 


1 HNSS-44004 14 58900 HNSS-44004 4-40 HEX NUT 

2 HSDH-41004 4 57177 164-07-BR-4-40-T 4-40 X 5/8 M/F SPACER 

3 20829 1 58900 20829 EL DISPLAY GLASS, 1 X 5 

4 20875 1 58900 20875 HOLDER, CONNECTOR 

5 20876 1 58900 20876 SEAL, EL DISPLAY 

6 20877 1 58900 20877 FRAME, EL DISPLAY 

7 20878-001 2 58900 20878-001 CONN ELASTOMER 1.440 LG. 

8 20878-002 2 58900 20878-002 CONN ELASTOMER 5.065 LG. 

9 70128 REF 58900 70128 EL DISPLAY ASSY PROC 

A1 20832 1 58900 20832 EL DISPLAY DRIVER PCB ASSEMBLY 

A2 20835 1 58900 20835 EL DISPLAY LOGIC PCB ASSEMBLY 

16869 DELAY LINE ASSEMBLY, Rev: D 


1 WCB0-00179 83 62277 RG179B RG179B/U 50 OHM COAX 

2 JRBF-18802 2 58900 JRBF-18802 SMC F FOR RG188 

3 10415 1 58900 10415 LABEL, OPTION IDENTIFICATION 

4 HSTH-41004 6 2R182 8835 4-40 X 5/8 HEX SPACER 

5 16960 1 58900 16960 DELAY LINE BOX 

6 16963 1 58900 16963 DELAY LINE BOX COVER 




16932-001 INTERCONNECT PCB ASSY, Rev: H 


6 HNSS-63205 1 58900 HNSS-63205 6-32 HEX NUT 

7 HBPP-A3206 8 58900 HBPP-A3206 10-32 X 3/8 PAN 

8 HWSS-40300 2 58900 HWSS-40300 #4 X 3/16 SPLIT LOCK 


10 HBUP-40006 2 46467 #4 X .375 SLFTAP #4 x 3/8" SELF TAPPING 

11 JMSF-00003 1 09769 552633-3 IEEE CONN MOUNTING 

12 HGP0-04000 1 32559 VG2-4 4" VERTICAL CARD GUIDE 

13 17249 1 58900 17249 SUPPORT BRACKET 

14 HBPP-44003 2 26233 NS137CR440R3 4-40 X 3/16 PAN 

15 HBPP-63208 1 58900 HBPP-63208 6-32 X 1/2 PAN 

16 16932-A01 1 58900 16932-A01 PCB ASSY PRE-WAVE,INTERCONNECT 

C1 CE15-09260 1 58900 CE15-09260 26,000 UF 10 V ELECT. 

C2 CE15-09450 1 58900 CE15-09450 45,000 UF 15 V ELECT 



C13 CE35-08100 1 55680 TLB1H102M 1000 UF 35 V AXIAL 

C14 CE35-08100 1 55680 TLB1H102M 1000 UF 35 V AXIAL 

J13 JMFP-02403 1 09769 552791-1 24 PIN IEEE CONNECTOR 

S1 SPP0-00101 1 09353 TP11SHABE SPST PC MT PUSHBUTTON 

16932-A01 PCB ASSY PRE-WAVE,INTERCONNECT, Rev: F 


1 20762 1 58900 20762 PC BD, INTERCONNECT 

2 21088 REF 58900 21088 SCHEMATIC, INTERCONNECT 8500A 


4 HSCR-40304 24 2R182 8703 #4 X 3/16 CLEAR SPACER 

5 HBPP-44008 24 58900 HBPP-44008 4-40 X 1/2 PAN 

C5 CC51-04100 1 04222 SR205C-104KAA .1 UF CERAMIC X7R 


C7 CC50-03100 1 54583 RD30HX7R103K .01 UF CERAMIC X7R 









CR1 DBMC-00010 1 58900 DBMC-00010 PE10 5A 100V BRIDGE RECTIFIER 

CR2 DRAE-00823 1 04713 1N823 1N823 6.3V REF DIODE 

J1 JPS1-20036 1 0HFJ2 MPS-0100-36-DW-6HK 72 PIN PC EDGE CONN 












J19 JIA0-01371 1 75263 1287 QUICK DISCONNECT TAB 






Parts Lists 

16932-A01 PCB ASSY PRE-WAVE,INTERCONNECT, Rev: F 




J25 JRBM-00101 1 09769 903-373J-51A SMB M RTANG PC MOUNT 

J26 JRBM-00101 1 09769 903-373J-51A SMB M RTANG PC MOUNT 

J27 JRBM-00100 1 58900 JRBM-00100 SMB M PC MOUNT 





R1 RC20-00056 1 01121 RC20GF5R6J 5.6 OHM 5% 1/2 W CARBON 




R5 RN55-11000 1 91637 RN55C1001F 1 K OHMS 1% MET FILM 


RP2 RM9S-21001 1 58900 RM9S-21001 10K OHM X 9 SIP NETWORK 


W1 WJIB-05024 1 63058 JO.500X0.125-PVC-24 .5" INSULATED JUMPER 






16995 PCB ASSY, POWER SUPPLY, Rev: G 



8 HSCR-40304 2 2R182 8703 #4 X 3/16 CLEAR SPACER 

9 HQH0-10050 2 30161 323005B00000 TO5 HEATSINK 

10 HHE0-00002 2 32559 CP-36 PC CARD EJECTOR LEVER 

11 HWHN-40301 4 04713 B51547F015 #4 NYLON SHOULDER WASHER 

12 18597 4 8W262 60-11-8302-1674 INSULATOR(T0-220) 

13 20639 1 58900 20639 HEATSINK, POWER SUPPLY 


15 HBPP-44008 2 58900 HBPP-44008 4-40 X 1/2 PAN 

16 16995-A00 1 58900 16995-A00 PCB ASSY PRE-WAVE, PWR SUPPLY 

C21 CE35-07100 1 55680 TLB1V101M 100 UF 35 V AXIAL 

F1 FMAC-01000 1 75915 312-010 10A MB FUSE 3AG 

F2 FMAC-01000 1 75915 312-010 10A MB FUSE 3AG 

Q1 QBPP-06489 1 58900 QBPP-06489 2N6489 15A 40V 75W PNP 

Q4 QBNP-06486 1 04713 2N6486 2N6486 15A 40V 75W NPN 

Q5 QBPP-06489 1 58900 QBPP-06489 2N6489 15A 40V 75W PNP 

Q10 QBNP-06486 1 04713 2N6486 2N6486 15A 40V 75W NPN 

S1 17185 1 59270 OA-250-QCV-3 SCD, SWITCH, THERMAL 

U1 UFN1-00324 1 01295 LM324N LM324AN QUAD OP AMP 

U2 UFN0-00358 1 58900 UFN0-00358 LM358 OP AMP 


U4 ULN0-00393 1 01295 LM393P LM393N VOLT COMPARATOR 

16995-A00 PCB ASSY PRE-WAVE, PWR SUPPLY, Rev: F 


1 16994 1 58900 16994 PC BOARD, POWER SUPPLY 8500 

2 16996 REF 58900 16996 SCHEMATIC, POWER SUPPLY 

3 HQIP-00050 4 13103 7717-22-N TO5 NYLON INSULATOR 

4 FHC0-00001 4 75915 102071 FUSE CLIP 

5 JSP0-10008 3 09769 2-640463-1 8 PIN DIP SOCKET 


C1 CC99-01220 1 3W023 DD221 220 PF 1000V CERAMIC X5F 

C2 CC50-02100 1 04222 SR155C122MAT .001 UF CERAMIC Y5P 


C4 CT25-R6680 1 31433 T354L686K025AS 68UF 25V RADIAL 










C14 CC98-01100 1 56289 10TCC-T10 100 PF 1 KV CERAMIC NPO 



C17 CC98-01100 1 56289 10TCC-T10 100 PF 1 KV CERAMIC NPO 



C22 CT35-R5100 1 31433 T356A105M035AS 1UF 35V TANTALUM 


CR1 DSA0-04148 1 58900 DSA0-04148 1N4148 G.P. DIODE 






Parts Lists 








CR10 DPAD-04383 1 58900 DPAD-04383 1N4383 1A 200V RECTIFIER 







CR21 DZAC-05229 1 04713 IN5229B IN5229 4.3 V ZENER 



Q2 QBNP-03053 1 04713 2N3053 2N3053 .7A 40V NPN 

Q3 QBPS-04314 1 58900 QBPS-04314 2N4314 65V .15A PNP 

Q6 QBNS-03565 1 27014 PN3565 PN3565 25V 300HFE NPN 

Q7 QBPS-04314 1 58900 QBPS-04314 2N4314 65V .15A PNP 

Q8 QBPS-04250 1 58900 QBPS-04250 2N4250 40V 2DB NF PNP 

Q9 QBNP-03053 1 04713 2N3053 2N3053 .7A 40V NPN 



R3 RN57-21000 1 58900 RN57-21000 10K OHM .1% MET FILM 


R7 RN57-12000 1 58900 RN57-12000 2.00 KOHM .1% METAL FILM 

R8 RW01-00002 1 59124 M01R24J .24 OHM 1 W WIREWOUND 

R9 RN57-22000 1 58900 RN57-22000 20.0 KOHM .1% MET FILM 



R12 RC32-01000 1 ——- SPR1-101-J 100 OHM 10% 1 W CARBON 

R13 RC32-01000 1 ——- SPR1-101-J 100 OHM 10% 1 W CARBON 

R14 RN55-12210 1 91637 RN55C2211F 2.21 K OHMS 1% MET FILM 




R18 RN55-12100 1 91637 RN55C2101F 2.1K OHMS 1% MET FILM 

R19 RN55-41000 1 91637 RN55C1004F 1 M OHMS 1% MET FILM 



R22 RAPK-05000 1 5Y491 66XR500 500 OHM 10% 20T PC MNT 



R25 RW01-00002 1 59124 M01R24J .24 OHM 1 W WIREWOUND 



R28 RN57-11000 1 91637 RN55C1001B 1K OHM .1% MET FILM 

R29 RW05-00001 1 91637 RW67VR10 0.1 OHM 5 W WIREWOUND 









R39 RG03-00150 1 91637 FP215R0 5% 15 OHM 10% METAL GLAZE 


R41 RN55-11780 1 91637 CCF55-2-1.78K1%T2T/R 1.78 KOHM 1% MET FILM 

R42 RAPK-15000 1 5Y491 66XR5K 5 K 10% 20T PC MNT 









R47 RW05-00001 1 91637 RW67VR10 0.1 OHM 5 W WIREWOUND 



R50 RG03-00150 1 91637 FP215R0 5% 15 OHM 10% METAL GLAZE 







R61 RN55-00100 1 91637 RN55C10R0F 10 OHMS 1% MET FILM 



R66 RN55-00825 1 91637 RN55C82R5F 82.5 OHMS 1% MET FILM 



TP1 ETT0-00001 1 63345 330.100W/ TIN PLATE TEST JACK PIN 











U5 UVP0-00385 1 04713 LM385BZ1.2 LM385BZ-1.2 1.2V REF 



Parts Lists 

21014 PCB ASSY GPIB/CAL CONTROL 8500, Rev: C 


9 HNKS-44004 1 58900 HNKS-44004 4-40 KEP NUT 

10 17240-001 1 27264 15-38-1024 JUMPER,INSULATED,2 POS 

11 17320 2 32559 CP-56-PA EJECTOR, PC CARD 1.50" LONG 


13 21014-A00 1 58900 21014-A00 PCB ASSY PRE-WAVE,GPIB 

Q8 QBNP-00029 1 01295 TIP29 TIP29 1A 40V 30W NPN 

U1 UGN0-09914 1 01295 TMS9914NL (ANL) TMS9914NL IEEE-488 

U2 UIN0-75162 1 01295 SN75162BN SN75162N IEEE BUFFER 

U3 UTN0-00321 1 01295 SN74LS32N SN74LS32N QUAD OR 

U4 UIN0-75160 1 01295 SN75160BN SN75160N IEEE BUFFER 

U6 UTN0-00001 1 01295 SN74LS00N SN74LS00 QUAD NAND 

U8 UGN0-08255 1 34335 8255A-5 8255A-5 PROG PIA 


U10 UIN0-07534 1 24355 AD7534JN AD7534JN 14 BIT DAC 



U13 UFN0-05135 1 01295 OP-07/CP HA5135-5 PRECISION OP AMP 


U15 ULN0-00311 1 01295 LM311P LM311N COMPARATOR 


U17 ULN0-00201 1 24355 ADG201AKN ADG201AKN SPST SWITCH 

U18 UFN0-34074 1 04713 MC34074L MC34074P QUAD OP AMP 

21014-A00 PCB ASSY PRE-WAVE, GPIB, Rev: C 


1 21013 1 58900 21013 PC BOARD, GPIB/CAL CONTROL 

2 21015 REF 58900 21015 SCHEMATIC, GPIB/CAL CONTROL 







C6 CC98-00330 1 ——- CCD-330 33 PF 1KV CERAMIC NPO 

C7 CT35-R5470 1 31918 TAPS4. 7M35 CAP TANTALUM 4.7MF 20% 35VDC 


C9 CC50-04220 1 31433 C322C224M5U5CA .22 UF CERAMIC Z5U 





C15 15776-028 1 90201 C20C101K5R5CA 100 PF CERAMIC X7R 
























C36 CT20-R6150 1 04222 TAP156K020CCS 15UF 20V TANTALUM 




C50 CC50-02220 1 04222 SR155C222KAA 2200PF CERAMIC X7R 





CR3 DSA0-04448 1 58900 DSA0-04448 1N4448 SWITCHING DIODE 





Q1 QBNS-03569 1 4U751 2N3569 PN3569 .5A 40V NPN 

Q2 QBPS-03644 1 58900 QBPS-03644 2N3644 .3 A 45 V PNP 

















R16 RAPK-15000 1 5Y491 66XR5K 5 K 10% 20T PC MNT 



R19 RN55-08450 1 91637 RN55C8450F 845 OHMS 1% MET FILM 




R28 RN55-15620 1 91637 RN55C5621B 5.62 K OHMS 1% MET FILM 


R38 RN57-31000 1 58900 RN57-31000 100 K OHM .1 % MET FILM 










R49 RN55-00402 1 91637 CCF55-2-40.2^1%T2T/R 40.2 OHM 1% MET FILM 










Parts Lists 














































16878 PCB ASSY., CPU, Rev: E 


10 WSB0-22000 0 16428 8021-C1000-22AWG 22 GAUGE BUS WIRE 



13 GL00-00001 8 58900 GL00-00001 1" x .5" LABEL 

14 19973 1 65249 BH-AA HOLDER, AA BATTERY, PC PINS 

15 19974 1 58900 19974 MOUNTING BLOCK, BATTERY HOLDER 

16 20803 1 58900 20803 PROM SET 8500A-STANDARD 

17 HBFP-44006 2 58900 HBFP-44006 4-40 X 3/8 FLAT 


19 16878-A00 1 58900 16878-A00 PCB ASSY PRE-WAVE, CPU 

BT1 19972 1 31586 LS14500 BATTERY, LITHIUM AA 3.6V 1.8Ah 

U1 UGN0-46818 1 04713 MC146818P MC146818P REAL TIME CLOCK 

U5 UMN0-06264 1 58900 UMN0-06264 HM6264LP-15 8K X 8 RAM 


U7 UTN0-02441 1 01295 SN74LS244N SNL4LS244N 8X DRIV/RECV 




U12 UGN0-68000 1 04713 MC68HC000P-12 HD68HC000P-8 COMPUTER 




U16 UTN0-01641 1 01295 SN74LS164N SN74LS164N SHIFT REGISTER 

U17 ULN0-00555 1 04713 MC1455P1 MC1455P 200MA TIMER 

U18 UTN0-00271 1 01295 SN74LS27N-TI 74LS27N 3X3 INPUT NOR 

U19 UTN0-00041 1 01295 SN74LS04N SN74LS04 HEX INVERTER 

U20 UTN0-00081 1 01295 SN74LS08N SN74LS08 QUAD AND 

U21 UTN0-00101 1 01295 SN74LS10N SN74LS10 TRIPLE NAND 

U22 UTN0-00051 1 01295 SN74LS05N 74LS05;HEX INVERTER 


U24 UTN0-00021 1 01295 SN74LS02N SN74LS02 QUAD NOR 


U26 UTN0-00003 1 58900 UTN0-00003 74HCT00N QUAD 2 IN NAND 



U32 UTN0-02451 1 01295 SN74LS245N SN74LS245N 8X TRANSCEIVE 

U33 UTN0-02451 1 01295 SN74LS245N SN74LS245N 8X TRANSCEIVE 

U34 UTN0-01541 1 58900 UTN0-01541 SN74LS154N 4 TO 16 DECODE 


U37 UTN0-01481 1 01295 SN74LS148 74LS148 PRIORITY ENCODER 


U39 UTN0-00741 1 04713 74LS74N 74LS74 DUAL D FLIP FLOP 



Y1 Y380-00003 1 58900 Y380-00003 32.768 KHZ CRYSTAL 



Parts Lists 

16878-A00 PCB ASSY PRE-WAVE, CPU, Rev: E 


1 16877 1 58900 16877 PC BOARD, CPU 8500 

2 16879 REF 58900 16879 SCHEMATIC, CPU 

3 JSP0-10064 1 09769 643575-3 64 PIN DIP SOCKET 








C2 CC99-02470 1 56289 5GA-D47 4700 PF 1000V CERAMIC 















C17 11501-007 1 3W023 CW20C103K CAP CER .01UF 10% 50V 

C18 11501-007 1 3W023 CW20C103K CAP CER .01UF 10% 50V 


C20 CC50-04470 1 04222 SR301E474MAA .47 UF CERAMIC Y5V 





C25 CC98-00220 1 56289 10TCC-Q22 22 PF 1KV CERAMIC NPO 





















C47 CV00-R9035 1 58900 CV00-R9035 9-35 PF VARIABLE 








CR2 DSA0-02900 1 28480 5082-2811 5082-2900 SCHOT DIODE 




16878-A00 PCB ASSY PRE-WAVE, CPU, Rev: E 




R2 RC07-52200 1 01121 RC07GF226J 22 MEG 5% 1/4 CARBON 











RP1 RM7S-14700 1 58900 RM7S-14700 4.7 KOHM X 7 SIP NETWORK 

RP2 RM7S-14700 1 58900 RM7S-14700 4.7 KOHM X 7 SIP NETWORK 











Y2 YX01-00012 1 04713 RASC03 12 MHZ OSCILLATOR 



Parts Lists 

16685 P.C. BRD. ASSY., DIGITAL DELAY, Rev: U 



8 17240-001 1 27264 15-38-1024 JUMPER,INSULATED,2 POS 

9 16685-A00 1 58900 16685-A00 PCB ASSY PRE-WAVE,DIG. DELAY 

C9 CF00-03100 1 90201 SXM110 .01UF 160V POLYSTYRENE 

C14 CF00-01220 1 90201 SXM322 220PF 160V POLYSTYRENE 

L1 17175 1 58900 17175 INDUCTOR, 3.5 TURNS 

L3 17174 1 58900 17174 CHOKE, 1.5 TURN 

U1 UTN0-02211 1 01295 SN74LS221N 74LS221 MONOSTABLE SCHMT 

U2 UTN0-01381 1 01295 SN74LS138N SN74LS138N 3 TO 8 DEC 



U5 UTN0-00201 1 01295 SN74LS20N 74LS20N DUAL 4 IN NAND 



U8 UTN0-01637 1 01295 SN74S163N SN74S163N 4 BIT COUNTER 

U9 UTN0-01631 1 01295 SN74LS163N SN74LS163N SYNCH COUNTER 




U13 UEN0-10124 1 04713 MC10124P MC10124P QUAD TTL TO ECL 

U14 13620-009 1 04713 MC10H016P I.C. - DIGITAL TTL 

U15 UTN0-00043 1 01295 SN74HCT04N 74HCT04 HEX INVERTER 

U16 UTN0-01571 1 58900 UTN0-01571 SN74LS157 QUAD 2 TO 1 MU 




U21 UEN0-10125 1 04713 MC10125P MC10125P QUAD ECL TO TTL 


U23 UEN0-10105 1 04713 MC10105P MC10105P TRIPLE OR/NOR 

U24 UEN1-10105 1 04713 MC10H105P MC10H105P TRIPLE OR/NOR 

U25 UEN0-10131 1 04713 MC10131L MC10131P DUAL D F/F 

U26 UEN0-10198 1 04713 MC10198L MC10198P MONOSTABLE MULTI 

U27 UEN1-10105 1 04713 MC10H105P MC10H105P TRIPLE OR/NOR 

U28 UEN1-10104 1 04713 MC10H104P MC10H104P 2 IN AND 

U29 UEN1-10131 1 04713 MC10H131P MC10H131P DUAL D F/F 

U30 UEN1-10121 1 04713 MC10H121P MC10H121 4X AND/OR/AND 




U35 13620-003 1 04713 MC10101P INTEGRATED CKT MC10101P 

U36 UIN1-00008 1 58900 UIN1-00008 DAC08EQ 8 BIT DAC 

U37 UFN0-00072 1 01295 TL072CP TL072CP DUAL FET OP AMP 

U38 UEN0-10198 1 04713 MC10198L MC10198P MONOSTABLE MULTI 

U39 ULN0-96687 1 24355 AD96687BQ AD96687BQ COMPARATOR 

U40 UIN0-00561 1 24355 AD561JN AD561JN 10 BIT DAC 




U44 UTN0-01231 1 01295 SN74LS123N SN74LS123N DUAL ONE SHOT 

Y1 Y250-03906 1 52847 CR-117/U 39.062500MHZ 39.0625 MHZ OVEN XTAL 




16685-A00 PCB ASSY PRE-WAVE,DIG. DELAY, Rev: U 


1 16684 1 58900 16684 DIGITAL DELAY PC BOARD 

2 16686 REF 58900 16686 SCHEMATIC, DIGITAL DELAY 









C6 CC98-00220 1 56289 10TCC-Q22 22 PF 1KV CERAMIC NPO 




C16 CC98-00470 1 ——- CCD470 47 PF 1KV CERAMIC NPO 



















































Parts Lists 






C78 CC50-04470 1 04222 SR301E474MAA .47 UF CERAMIC Y5V 

C79 CV00-R9035 1 58900 CV00-R9035 9-35 PF VARIABLE 




















C103 CT35-R5220 1 31433 T356C225K035AS 2.2UF 35V TANTALUM 

C104 CC98-00100 1 ——- CCD100 10 PF 1000 V CERAMIC NPO 



C107 CC51-01470 1 51642 150-50-X7R-471K 470 PF CERAMIC X7R 


CR1 DSA0-02900 1 28480 5082-2811 5082-2900 SCHOT DIODE 



Q1 QBNS-03646 1 04713 MPS3646 2N3646 40V 350 MHZ NPN 

Q5 QBNS-03563 1 27014 PN3563 PN3563 15V 600MHZ NPN 


Q7 QBPS-04121 1 58377 PN4121 2N4121 .05A 40V PNP 


























R23 RN55-15110 1 91637 RN55C5111F 5.11 K OHMS; METAL FILM 











R31 RN55-11240 1 91637 CCF55-2-1.24K1%T2T/R 1.24 KOHM 1% MET FILM 

R32 RN57-01000 1 58900 RN57-01000 100.0 OHM .1% MET FILM 





R37 RN57-21500 1 58900 RN57-21500 15.0 K OHM .1 % MET FILM 









R46 RF07-44700 1 65940 R25X-R02-J-475 4.7M OHMS 5% CARB FILM 








R54 RN55-15110 1 91637 RN55C5111F 5.11 K OHMS; METAL FILM 


























R81 RAPK-22000 1 5Y491 66XR20K 20K 10% 20T PC MNT 


RP1 RM9S-03900 1 71450 750-101-R390 390 X 9 SIP NETWORK 

RP2 RM7S-03900 1 71450 750-81-R390 390 OHM X 7 SIP NETWRK 








Parts Lists 



RP8 RM9S-06800 1 58900 RM9S-06800 680 OHM X 9 SIP NETWORK 


RP10 RM9S-03900 1 71450 750-101-R390 390 X 9 SIP NETWORK 






















U34 UEG0-09685 1 58900 UEG0-09685 AD9685BH COMPARATOR 




20741 ANALOG PCB ASSY, Rev: M 



10 20741-A00 1 58900 20741-A00 PCB ASSY PRE-WAVE, ANALOG 

C23 CF00-03100 1 90201 SXM110 .01UF 160V POLYSTYRENE 

C70 CF00-02240 1 90201 SXM224 2400PF 160V POLYSTYRENE 

T1 20131 1 58900 20131 TRANSFORMER,SAMPLER 



U3 UTN0-00271 1 01295 SN74LS27N-TI 74LS27N 3X3 INPUT NOR 



U6 UTN0-08735 1 01295 SN74ALS873ANT SN74ALS873ANT DUAL LATCH 

U7 UIN0-00574 1 58900 UIN0-00574 AD574AJ 12 BIT ADC 

U8 UIN0-07542 1 1ES66 MX7542KN AD7542KN 12 BIT D/A 

U9 14632 1 58377 CD4069UBCN INTEGRATED CKT MM74CO4N 

U10 14632 1 58377 CD4069UBCN INTEGRATED CKT MM74CO4N 






U16 UIN0-00398 1 58900 UIN0-00398 LF398AN SAMPLE/HOLD 

U17 UFN0-34074 1 04713 MC34074L MC34074P QUAD OP AMP 






U23 ULN0-00339 1 04713 LM339N LM339N COMPARATOR 

U25 ULN0-00444 1 17856 DG444DJ DG444DJ QUAD SPST SWITCH 



U28 UFN0-00356 1 04713 LF356BN-MOT LF356BN OP AMP 

U29 UFN0-00356 1 04713 LF356BN-MOT LF356BN OP AMP 

U30 UFN0-00847 1 24355 AD847JN AD847JN OP AMP 

U31 UAN0-05002 1 2M881 HA3-5002-5 HA3-5002-5 VIDEO BUFFER 


U33 UAN0-05002 1 2M881 HA3-5002-5 HA3-5002-5 VIDEO BUFFER 



Parts Lists 

20741-A00 PCB ASSY PRE-WAVE, ANALOG, Rev: M 


1 20740 1 58900 20740 PC BOARD, ANALOG 

2 20742 REF 58900 20742 SCHEMATIC, ANALOG 















C81 CC50-01100 1 04222 SR151A101JAA 100 PF CERAMIC NPO 







C15 CC50-B4470 1 04222 SR305C474KAA .47 UF CERAMIC X7R 



















C35 CC99-02470 1 56289 5GA-D47 4700 PF 1000V CERAMIC 












C47 CD99-01470 1 ——- CM06FD471F03 470 PF DIP MICA 














C57 CD99-01470 1 ——- CM06FD471F03 470 PF DIP MICA 






C66 CC50-02470 1 31433 C315C472K1R5CA 4700 PF CERAMIC X7R 

C67 CC50-02270 1 31433 C315C272K1R5CA C9248 2700 PF CERAMIC X7R 




C72 CC98-00680 1 90201 CPC680J 68 PF 1 KV CERAMIC NPO 








C100 CC51-01220 1 3W023 CW15C221K 220 PF CERAMIC X7R 

C102 CC00-02220 1 04222 SR201A222KAA 2200 PF CERAMIC COG 




C109 CE50-R5330 1 55680 UVX1H3R3MAA 3.3UF 50V RADIAL 


C111 CE50-R5330 1 55680 UVX1H3R3MAA 3.3UF 50V RADIAL 





C116 15776-028 1 90201 C20C101K5R5CA 100 PF CERAMIC X7R 













CR14 DSA0-02800 1 28480 1N5711 5082-2800 SCHOT DIODE 





















Parts Lists 




















































































R84 RN57-18000 1 58900 RN57-18000 8.00 K OHM .1 % MET FILM 


















R104 RN55-00750 1 91637 RN55CMF25T75E 75.0 OHMS 1% MET FILM 








R116 RN57-11000 1 91637 RN55C1001B 1K OHM .1% MET FILM 



R120 RN55-42210 1 91637 RN55C2204F 2.21 M OHM 1% MET FILM 






R135 RN55-00464 1 91637 RN55D 46.4 OHM 1% 46.4 OHM 1% MET FILM 

R136 RC07-52200 1 01121 RC07GF226J 22 MEG 5% 1/4 CARBON 

R138 RN57-22928 1 58900 RN57-22928 29.28 KOHM;.1% MET FILM 












R152 WJIB-05024 1 63058 JO.500X0.125-PVC-24 .5" INSULATED JUMPER 



Parts Lists 


























XR141 LCR0-13801 1 02114 56-59065/3B FERRITE BEAD 

XR166 LCR0-13801 1 02114 56-59065/3B FERRITE BEAD 




20195 PCB ASSY, FR PNL INTERFACE, Rev: D 


8 HNKS-44004 2 58900 HNKS-44004 4-40 KEP NUT 

9 HIBR-00440 3 53387 SP5303-GRAY MOLDED BUMPER 

10 18597 2 8W262 60-11-8302-1674 INSULATOR(T0-220) 

11 HQH0-62200 2 30161 5771B TO220 HEATSINK 


13 20195-A00 1 58900 20195-A00 PCB ASSY PRE-WAVE,FRT PNL INT 

L1 20566 1 58900 20566 INDUCTOR, 15uH 1.2A 

Q1 QMNP-00540 1 66958 IRF540 IRF540 100V 28A NMOS FET 

T1 20634 1 58900 20634 TRANSFORMER, FLYBACK 


U2 UGN0-08279 1 34335 AM8279DC 8279 KEY/DISPLAY INTERFACE 

U3 UTN0-01751 1 01295 SN74LS175N SN74LS175 QUAD D F/F 

U4 UIN0-75451 1 01295 SN75451BP SN75451BP DUAL DRIVER 

U5 UTN0-01561 1 01295 SN74LS156N SN74LS156N 2 TO 4 DECDR 


U7 ULN0-03082 1 58900 ULN0-03082 CA3082 TRANSISTOR ARRAY 

U8 ULN0-00556 1 01295 NE556N LM556N DUAL TIMER 


U10 20761 1 58900 20761 PAL, FRONT PANEL KNOB LOGIC 

U11 UGD0-61830 1 61485 HD61830B00H HD61830 LCD CONTROLLER 


U13 UTN0-00043 1 01295 SN74HCT04N 74HCT04 HEX INVERTER 


U15 UFN1-00358 1 01295 LM358AP LM358AN DUAL OP AMP 

U16 UTN0-01611 1 01295 SN74LS161AN SN74LS161AN COUNTER 


U18 UTN0-00744 1 01295 SN74F74N MC74F7AN 100MHZ DUAL D 

U19 UIN0-03845 1 66958 UC3845N UC3845 PWM CONTROLLER 


U22 URC1-07812 1 04713 MC78T12CT MC78T12CT 3A 12V REG 

20195-A00 PCB ASSY PRE-WAVE,FRT PNL INT, Rev: C 


1 20194 1 58900 20194 PC BOARD FR PNL INTERFACE 









C4 CE50-R6220 1 55680 ULB1H220MAA 22UF 50V RADIAL 











C30 CE50-R5100 1 55680 ULB1H010MAA 1UF 50V RADIAL 





Parts Lists 

















C50 CF50-R5100 1 65964 MMK5105K50L4C 1UF 50V POLYESTER 

C51 CF63-R4100 1 68919 MKS2-0.1UF-10%-63 .1UF 63V POLYESTER 

C52 CC50-03220 1 31433 C315C223K5R5CA .022 UF CERAMIC X7R 

C53 CC50-02270 1 31433 C315C272K1R5CA C9248 2700 PF CERAMIC X7R 

C55 CF63-R4100 1 68919 MKS2-0.1UF-10%-63 .1UF 63V POLYESTER 


C57 CE25-R7470 1 55680 UVX1E471M 470 UF 25V RADIAL 




C61 CE25-R7100 1 00656 AMR101M025 100 UF 25V RADIAL LEAD 

C62 CF50-R5100 1 65964 MMK5105K50L4C 1UF 50V POLYESTER 


C65 CE00-R6470 1 58900 CE00-R6470 47UF 100V RADIAL 

C66 CE00-R6470 1 58900 CE00-R6470 47UF 100V RADIAL 

C67 CE00-R5471 1 55680 UVX2E4R7MTP 4.7 UF 250V RADIAL 


C70 CE00-R5471 1 55680 UVX2E4R7MTP 4.7 UF 250V RADIAL 








CR5 DPAF-04937 1 04713 1N4937 1N4937 1A 600V DIODE 


CR9 DPAE-00140 1 04713 MUR140 MUR140 1A 400V RECTIFIER 

CR11 DPAE-00140 1 04713 MUR140 MUR140 1A 400V RECTIFIER 

CR14 DPAF-04937 1 04713 1N4937 1N4937 1A 600V DIODE 

J1 JIA2-26318 1 09769 1-87227-3 26 PIN STRIPLINE PLUG 

Q2 QJNS-07000 1 04713 2N7000 2N7000 5 OHM N CH JFET 
































R44 RW00-00003 1 91637 NS-1/4-0.25 OHM 1% .25 OHM .25 W WIREWOUND 













RP1 RM4S-00220 1 71450 750-83-R220 22 OHM X 4 SIP NETWORK 

RP2 RM4S-00220 1 71450 750-83-R220 22 OHM X 4 SIP NETWORK 

RP3 RM5S-11001 1 58900 RM5S-11001 1 KOHM X 5 SIP NETWORK 

RP4 RM5S-11001 1 58900 RM5S-11001 1 KOHM X 5 SIP NETWORK 

RP5 RM7S-04700 1 58900 RM7S-04700 470 X 7 SIP NETWORK 













U20 URP0-78120 1 04713 MC78L12ACP MC78L12CP .1A 12V REG 

Y1 YX00-00004 1 61429 F1100E-4.000MHZ 4 MHZ OSCILLATOR 



Parts Lists 

20526-001 PC BOARD ASSY, FRONT PANEL, Rev: A 


1 20525 1 58900 20525 PC BOARD, FRONT PANEL 

2 HSCR-41103 7 32559 908-680 .12 ID NYLON SPACER 

3 16943-001 1 58900 16943-001 KEYCAP ENGRAVED “1" 


5 16943-003 1 58900 16943-003 KEYCAP EVGRAVED “3" 








13 16943-011 1 58900 16943-011 KEYCAP ENGRAVED “.” 

14 16943-012 1 58900 16943-012 KEYCAP ENGRAVED “-” 

15 16943-032 1 58900 16943-032 KEYCAP ENGRAVED “Clear” 

16 16943-033 1 58900 16943-033 KEYCAP ENGRAVED “ms” 

17 16943-034 1 58900 16943-034 KEYCAP ENGRAVED “us” 

18 16943-035 1 58900 16943-035 KEYCAP ENGRAVED “ns” 

19 16943-036 1 58900 16943-036 KEYCAP ENGRAVED “Bksp” 

20 16943-037 2 58900 16943-037 KEYCAP ENGRAVED “” 

21 SPPL-K0104 4 04426 80-390134 BONE GRAY KEYCAP 

22 17030 3 58900 17030 MODIFICATION LIGHTED KEYCAP 

CR1 ILYR-00125 1 28480 HLMP-1440 YELLOW LED 










S1 SPPL-22500 1 04426 39-22100 PUSH BUTTON SWITCH 






S7 SPPL-L0100 1 04426 80-390100 LIGHT PIPE 




















S10L SPPL-L0100 1 04426 80-390100 LIGHT PIPE 






20055-001 ASSY, 1GHZ CALIBRATOR TYPE N, Rev: C 


1 20055-A01 1 58900 20055-A01 CALIBRATOR SUB ASSY,TYPE N 

2 30087 REF 58900 30087 8500/8500A CAL TEST PROC 

20055-A01 CALIBRATOR SUB ASSY,TYPE N, Rev: B 


1 17694 1 58900 17694 PC BOARD, CALIBRATOR 1 GHZ 

2 ETIT-44038 1 58900 ETIT-44038 INSULATED TURRET TERMINAL 

3 17067 1 58900 17067 HOUSING, CAL, 1 GHz 

4 17068 1 58900 17068 COVER, CAL, 1 GHz 

5 17165 1 58900 17165 COVER PLATE TRANSISTOR 

6 HICP-00001 1 06383 FCMI-A-14 CABLE HOLD DOWN CLIP 

AT1 19192-001 1 66126 PCAW-9 ATTEN CHIP LOW PWR 4GHZ 9dB 



C1 CK50-01100 1 58900 CK50-01100 100 PF CERAMIC NPO 

















CR1 13618 1 58900 13618 DIODE,uWAVE PIN SW,.3PF,100ns 










FL1 LFT0-83219 1 58900 LFT0-83219 FEED THRU FILTER 











J1 17000 1 09769 WMI DWG 17000 CONN,TYPE N,FEMALE,PANEL MOUNT 

Q1 QBNS-05108 1 04713 2N5108 2N5108 30V 1200 MHZ NPN 





Parts Lists 

20055-A01 CALIBRATOR SUB ASSY,TYPE N, Rev: B 



R4 RN50-11000 1 91637 RNC50H1001F 1.00 K OHMS 1% MET FILM 


R8 RN50-04990 1 58900 RN50-04990 499 OHMS 1% METAL FILM 














RT1 RTB0-26800 1 58090 BR16PB683K 68 KOHM THERMISTOR BEAD 

W1 17098 1 58900 17098 CABLE ASSY, CALIBRATOR 1 GHz 




7.3 List of Manufacturers 

The names and addresses of manufacturers cited in the preceding parts lists are shown in Table 7-1. Each 

manufacturer is listed under its CAGE number (COMMERCIAL AND GOVERNMENT ENTITY), as 

noted in the parts lists. In a few cases, no CAGE number has been assigned; these manufacturers are 

referenced by Giga-tronics codes which are shown at the end of the list. 

Table 7-1. Manfacturer’s List 

CAGE NAME ADDRESS 

0ABX4 Comptec Inc 7837 Custer School Rd Custer WA 98240 

0AG18 Hirose Electric USA Inc Chatsworth CA 

0AX52 Ditom Microwave Inc 1180 Coleman Ave #103 San Jose CA 95110 

0BE81 Aerovox-Mallory 20 Aberdeen Dr Glasgow KY 42141 

0B0A9 Dallas Semiconductor Corp 6350 Beltwood Pky S Dallas TX 75244 

0B549 Siemens Components Inc Semiconductor 2191 Laurelwood Rd Santa Clara CA 95054 

Group 

0D2A6 Mitsubishi Electronics Inc 1050 East Arques Ave Sunnyvale CA 94086 

0D3V2 Menlo Industries Inc 44060 Old Warm Springs Blvd Fremont CA 94538 

0EUK7 All American Transistor of California Inc 369 Van Ness Way Suite 701 Torrance CA 90501 

0GP12 Radiall Inc 150 Long Beach Blvd Stratford CT 06497 

0GYA7 Signal Transformer Co 500 Bayview Ave Inwood NY 11696 

0HS44 Pacific Millimeter 189 Linbrook Dr San Diego CA 92111 

0HFH6 Futaba Corporation of America 555 West Victoria St Compton CA 90220 

0HFJ2 Microplastic 9180 Gazette Ave Chatsworth CA 91311 

0HIN5 Marcon America Corp 998 Forest Edge Dr Vernon Hills IL 60061 

0H379 Aerowave Inc 344 Salem St Medford MA 02155 

0J7V3 Amp Inc 19200 Stevens Creek Blvd Suite 1 Cupertino CA 95014 

0JNR4 Dupont Eelectronics Customer Service 825 Old Trail Rd PO Box 80019 Wilmington DE 19880-0019 

Center 

0KA21 Stetco Inc 3344 Schierhorn Ct Franklin Park IL 60131 

00443 Waveline Inc 160 Passaic Ave West Caldwell NJ 07006 

00656 Aerovox Inc 740 Belleville Ave New Bedford MA 02745 

00750 Air Track Mfg Corp College Park MD 

00809 Croven Crystals 500 Beech St Whitby Ontario CAN L1N5S5 

00815 Midland - Ross 357 Beloit St Burlington WI 53105 

01121 Allen-Bradley Co 1201 South 2nd St Milwaukee WI 53204 

01295 Texas Instruments Inc 13500 N Central Expwy Dallas TX 75265 

01963 Cherry Electrical Products Corp 3600 Sunset Ave Waukegan IL 60087 

02113 Coilcraft Inc 1102 Silver Lake Dr Cary IL 60013-1658 

02490 Electronic Devices Inc Hampden MA 

02660 Amphenol Corp 358 Hall Ave Wallingford CT 06492 

02735 RCA Corp Route 202 Somerville NJ 08876 

03614 Bussman Mfg 114 Old St Rd PO Box 144 St Louis MO 63178 

04222 AVX Ceramics Div of AVX Corp 19th Ave South PO Box 867 Myrtle Beach SC 29577 

04426 ITW Switches 6615 West Irving Park Rd Chicago IL 60634 

04552 Grace W R and Co 869 Washington St Canton MA 02021 

04713 Motorola Inc 5005 East McDowell Rd Phoenix AZ 85008 

05236 Jonathan Manufacturing Corp 1101 South Acacia Ave Fullerton CA 92631 

05245 Corcom Inc 1600 Winchester Rd Libertyville IL 60048 

05276 ITT Pomona Electronics Div 1500 E 9th St PO Box 2767 Pomona CA 91766 

05791 Lyn-Tron Inc 3150 Damon Way Burbank CA 91505 

05820 EG and G Wakefield Engineering 60 Audubon Rd Wakefield MA 01880 

05905 Jerobee Industries Inc Redmond WA 

06049 Topaz Inc 9192 Topaz Way San Diego CA 92123 



Parts Lists 


06090 Raychem Corp 300 Constitution Dr Menlo Park CA 94025-1111 

06349 Cam-Lok Div Empire Product Inc 10540 Chester Rd Cincinnati OH 45215 

06383 Panduit Corp 17301 Ridgeland Tinley Park IL 60477 

06540 New Haven Mfg Corp Amatom Div 446 Blake St New Haven CT 06515 

06776 Robinson Nugent Inc 800 East 8th St New Albany IN 47150 

06915 Richco Plastics Co 5825 N Tripp Ave Chicago IL 60646-6013 

07115 Corning Glass Works Houghton Pk Corning NY 14830 

07180 Sage Laboratories Inc East Natick Industrial Park 3 Huron Dr Natick MA 01760 

07263 Fairchild Semiconductor Corp Cupertino CA 

07512 Oak Materials Group Inc McCaffery St Hoosick Falls NY 12090 

07556 Calabro Industries Inc 1372 Enterprise Dr West Chester PA 19380 

09022 Cornell-Dubilier Electronics 1605 East Rodney French Blvd New Bedford MA 02741 

09353 C and K Components Inc 15 Riverdale Ave Newton MA 02158 

09922 Burndy Corp 1 Richards Ave Norwalk CT 06856 

09969 Dale Electronics Inc East Highway 50 PO Box 180 Yankton SD 57078 

1AU47 Lucas Weinschel Inc 1 Weinschel Ln PO Box 6001 Gaithersburg MD 

1BH13 Fenwall Electronics Inc 64 Fountain St Framingham MA 01701-6211 

1BR23 CW Industries Inc Atlanta GA 04000 

1CY63 Sierra Microwave Technology 11295-B Sunrise Gold Circle Rancho Cordova CA 95670 

1DS68 Sumner Mfg Inc Hwy 411 S-Sumner Dr PO Drawer A Rome GA 30162 

1ES66 Maxim Intergrated Products 510 North Pastoria Ave Sunnyvale CA 94086 

1E584 Electrical Wire Products Bay Associates Inc 150 Jefferson Dr Menlo Park CA 94025-1115 

1FN41 Atmel Corp 2125 Onel Dr San Jose CA 95131 

1JJ60 Applied Tooling and Mfg Inc 1115 Industrial Ave Escondido CA 92025 

1W232 Spacek Labs 528 Santa Barbara St Santa Barbara CA 93101 

1Y147 Virtech 805 G University Ave Los Gatos CA 95030 

11532 Teledyne Relays 12525 Daphne Ave Hawthorne CA 90250 

11769 Elco/Dyntech Div of Elco Corp 1225 East Wakeham Ave Santa Ana CA 92702 

12020 Ovenaire Div of Electronic Tech 706 Forrest St Charlottesville VA 22901 

12457 Merrimac Industries Inc 41 Fairfield Pl West Caldwell NJ 07006 

13103 Thermalloy Co Inc 2021 W Valley View Lane PO Box 810839 Dallas TX 75381 

13511 Amphenol Cadre Div Bunker Ramo Corp Los Gatos CA 

13708 Allied Components Inglewood CA 

13919 Burr-Brown Corp 6730 S Tucson Blvd Tucson AZ 85734 

14482 Watkins-Johnson Co 3333 Hillview Ave Palo Alto CA 94304 

14552 Microsemi Corp 2830 S Fairview St Santa Ana CA 92704-5948 

14604 Elmwood Sensors Inc 500 Narragansett Park Dr Pawtucket RI 02861 

14936 General Instrument Corp Power 

600 West John St Hicksville NY 11802 

Semiconductor Div 

15268 RHG Electronics Laboratory Inc 161 East Industry Ct Deer Park NY 11729 

15450 Erie Specialty Products Inc 645 W 11th Street Erie PA 16512 

15542 Mini-Circuits Laboratory 2625 East 14th St Brooklyn NY 11235 

15915 Tepro of Florida Inc 2608 Enterprise Rd Clearwater FL 33517 

16179 M/A-Com Omni Spectra Inc 21 Continental Blvd Merrimack NH 03054 

16352 Codi Semiconductor Inc 144 Market Street Kenilworth NJ 07033 

16428 Cooper Industries Inc 350 NW N St Richmond IN 47374 

16453 Western Microwave Inc 495 Mercury Dr Sunnyvale CA 94086 

16508 Aerovox Corp 19th Ave S PO Box 867 Myrtle Beach SC 29577 

16733 Radio Frequency Systems Inc Cablewave 60 Dodge Ave North Haven CT 06473 

Systems Div 

17217 Gore W L and Associates Inc 555 Paper Mill Rd Newark DE 19714 

17540 Alpha Industries Inc 20 Sylvan Rd Woburn MA 01801 

17856 Siliconix Inc 2201 Laurelwood Rd Santa Clara CA 95054 

18041 Diodes Inc Power Components Div 21243 Ventura Blvd Woodland Hills CA 91364-2109 





18310 Concord Electronics Corp 30 Great Jones St New York NY 10012 

18324 Signetics Corp 4130 South Market Ct Sacramento CA 95834 

18364 Mag-Tool Co 940 American St San Carlos CA 94070 

18714 RCA Corp Findlay Plant 1700 Fostoria Rd Findlay OH 45840 

18736 Voltronics Corp West St East Hanover NJ 07936 

19701 Mepco/Electra Inc PO Box 760 Mineral Wells TX 76067 

2J873 Celeritex Inc 617 River Oaks Pky San Jose CA 95134 

2J899 Dynawave Inc 94 Searle St PO Box 938 Georgetown MA 01833 

2M734 Panasonic Co PO Box 1502 Secaucus NJ 07094 

2M881 Harris Corp Harris Semiconductor 883 Stierling Rd Suite 8120 Mountain View CA 94043-1930 

2R182 Smith H H Co 325 N Illinois St Indianapolis IN 46204-1703 

2V941 Microsource Inc 1269 Corporate Ctr Pky Santa Rosa CA 95407 

20550 Engineering Mfg Co Sheboygan WI 

20944 Wiltron Co 805 East Middlefield Rd Mountain View CA 94042 

20999 Minnesota Mining and Mfg Co 3M Center St Paul MN 55101 

21604 Buckeye Stamping Co 555 Marion Rd Columbus OH 43207 

21847 TRW Microwave Inc 825 Stewart Dr Sunnyvale CA 94086 

22519 Data Delay Devices 385 Lakeview Ave Clifton NJ 07011 

23499 Judd Wire Inc 870 Los Vallecitos Blvd San Marcos CA 92069 

23899 Van Petty Mfg Inc 1168 Tourmaline Dr Newbury Park CA 91320 

23936 Pamotor 770 Airport Blvd Burlingame CA 94010 

24355 Analog Devices Inc Rt 1 Industrial Park Norwood MA 02062 

24539 Avantek Inc 3175 Bowers Ave Santa Clara CA 95054 

24759 Lenox-Fugle Electronics Inc 100 Sylvania Place South Plainfield NJ 07080-1448 

24931 Specialty Connector Co Inc 2100 Earlywood Dr PO Box 547 Franklin IN 46131 

24995 Environmental Container System 3560 Rouge River Hwy Grants Pass OR 97526 

26066 Minnesota Mining and Mfg. Co 3M Center St Paul MN 55101 

26629 Frequency Sources Inc 16 Maple Rd Chelmsford MA 01824 

26692 B and S Tool & Die Company 2300 Sulphur Spring Rd Baltimore MD 21227 

26922 Cetec Corp 9900 Baldwin Place El Monte CA 91731 

26923 Control Master Products Inc 1062 Shary Circle Concord CA 94518 

27014 National Semiconductor Corp 2900 Semiconductor Dr Santa Clara CA 95051 

27264 Molex Inc 2222 Wellington Ct Lisle IL 60532 

27802 Vectron Laboratories Inc 166 Gover Ave Norwalk CT 06850 

27851 Film Microelectronics 17 A St Burlington MA 01803 

28480 Hewlett Packard Co 3000 Hanover St Palo Alto CA 94304 

28520 Heyco Molded Products 750 Boulevard PO Box 160 Kenilworth NJ 07033 

29005 Storm Products Co 112 South Glasglow Ave Inglewood CA 90301 

29111 Trak Microwave Corp 735 Palomar Ave Sunnyvale CA 94086 

29990 American Technical Ceramics One Nordon Lane Huntington Stn NY 11746 

3A054 McMaster-Carr Supply Co 9630 Norwalk Blvd Santa Fe Springs CA 90670 

3E364 Vemaline 333 Strawberry Field Rd Warwick RI 02887 

3W023 Philips Components Discrete Product Div 5083 Kings Hwy Saugerties NY 12477 

3Z990 Tech Pro Inc 6243 E US Hwy 98 Panama City FL 32404-7434 

30035 Jolo Industries Inc 13921 Nautilus Dr Garden Grove CA 92643-4026 

30817 Instrument Specialties Co Inc Exit 53 Route 80 PO Box A Delaware Water Gap PA 18327 

31433 Kemet Electronics Corp 2835 Kemet Way Simpsonville SC 29681 

31703 Gudrun Frederickson Co Oakland CA 

31757 Micrpac Industries Inc 905 E Walnut St Garland TX 75040 

31781 Edac Inc 40 Tiffield Rd Scarborough Ont CAN M1V 5B6 

31918 ITT Schadow Inc 8081 Wallace Rd Eden Prarie MN 55344 

32293 Intersil Inc 2450 Walsh Ave Santa Clara CA 95051 

32559 Bivar Inc 4 Thomas St Irvine CA 92718 



Parts Lists 


32767 Griffith Plastics Corp 1027 California Dr Burlingame CA 94010 

32997 Bourns Inc Trimpot Division 1200 Columbia Ave Riverside CA 92507 

33592 Miteq Inc 100 Davids Dr Huappauge NY 11787 

34031 Analog Devices 7810 Success Rd Greensboro NC 27409 

34078 Midwest Microwave Inc 3800 Packard Rd Ann Arbor MI 48104 

34335 Advanced Micro Devices Inc 901 Thompson Place Sunnyvale CA 94086 

34553 Amperex Electronic Corp Hauppauge NY 32732 

34576 Rockwell International Corp 4311 Jamboree Rd Newport Beach CA 92660 

34781 MCW Industries 129 Southside Drive Charlotte NC 28210 

34785 Dek Inc 3480 Swenson Ave St Charles IL 60174 

36437 Star Stainless Products Ltd Montreal Que CAN H4T1N8 

4F708 Hammond Mfg Co US Inc 1690 Walden Drive Buffalo NY 14225 

4R125 Magnetec Corp 61 W Dudleytown Rd Bloomfield CT 06002 

4S028 Brady W M Co Industrial Products Div Milwaukee WI 

4T165 NEC Electronics USA Inc Electron Div 401 Ellis St P.O. Box 7241 Mountain View CA 94039 

4U402 Roederstein Electronics Inc 2100 W Front St Statesville NC 28677-3651 

4U751 Advanced Semiconductors Inc 7525 Etmel Ave Unit 6 North Hollywood CA 91605-1912 

46384 Penn Engineering & Mfg Corp Old Easton Rd PO Box 1000 Danboro PA 18916 

5H281 Allmetal Screw Products Arlington TX 

5J927 Interface Technology Div of Dynatech Corp 2100 E Alcosta Ave Glendora CA 91740 

50721 Datel Inc 11 Cabot Blvd Mansfield MA 02048 

51167 Aries Electronics Inc 62 Trenton Ave Frenchtown NJ 08825 

51284 Mos Technology Inc 950 Rittenhouse Rd Norristown PA 19401 

51642 Centre Engineering Inc 2820 East College Ave State College PA 16801 

51705 Ico-Rally Corp 2575 East Bayshore Rd Palo Alto CA 94303 

52063 Exar Integrated Systems 2222 Gume Dr PO Box 49007 San Jose CA 95161-9007 

52072 Circuit Assembly Corp 18 Thomas St Irvine CA 92718 

52648 Plessey Trading Corp 1641 Kaiser Ave Irvine CA 92714 

52683 Baytron Co Inc 344 Salem St Medford MA 02155 

52763 Stettner Electronics Inc 6135 Airways Blvd Chattanooga TN 37421 

52840 Western Digital Corp 3128 Red Hill Ave Costa Mesa CA 92626 

53387 Minnesota Mining & Mfg Co Electronic 

Products Div 3M 

Austin TX 

53421 Tyton Corp 7930 N Faulkner Rd PO Box 23055 Milwaukee WI 53223 

53673 Thomson-CSF Components Corp 6660 Variel Ave Canoga Park CA 91304 

54186 Micro Power Systems Inc 3100 Alfred St Santa Clara CA 95050 

54343 Riedel M W and Co 300 Cypress Ave Alhambra CA 91801 

54487 Micronetics Inc 36 Oak St Norwood NJ 07648 

54516 National Cable Molding Corp 136 San Fernando Rd Los Angeles CA 90031 

54558 SDI Inc North Billerica MA 

54583 TDK Electronics Corp 12 Harbor Park Dr Port Washington NY 11550 

55153 Dielectric Laboratories Inc 69 Albany St Cazenovia NY 13035 

55261 LSI Computer Systems Inc 1235 Walt Whitman Rd Melville NY 11747 

55285 Bergquist Co Inc 5300 Edina Industrial Blvd Minneapolis MN 55435 

55322 Samtec Inc 810 Progress Blvd PO Box 1147 New Albany IN 47150 

55387 Pamtech 8030 Remmet Ave Canoga Park CA 91304 

55566 RAF Electronic Hardware Inc 95 Silvermine Rd Seymour CT 06483-3915 

55576 Synertek 3001 Stender Way Santa Clara CA 95051 

55680 Nichicon America Corp 927 E State Pky Schaumburg IL 60195 

55801 Compensated Devices Inc 166 Tremont St Melrose MA 02176-2204 

55989 Semicon Inc Div of the Lorvic Corp 8810 Frost Ave St. Louis MO 63134-1002 

56248 Consolidated Refining Co 115 Hoyt Ave Mamaroneck NY 10543 

56289 Sprague Electric Co 87 Marshall St North Adams MA 01247 

56501 Thomas & Betts Corp 1001 Frontier Rd Bridgewater NJ 08807 





56563 Alatec Products 12747 Saticoy St North Hollywood CA 91605 

56866 Quality Thermistor Inc 2147 Centurion Pl Boise ID 83709 

57032 Daden Associates Inc 23011 Moulton Pky A-12 Laguna Hills CA 92653 

57793 United Microwave Products Inc 185 West 205th St Torrance CA 90503 

57834 Brim Electronics Inc 120 Home Pl Lodi NJ 07644-1514 

58090 Thermometrics Inc 808 Rt 1 Edison NJ 08817-4624 

58202 Innowave Inc 15555 Concord Circle Morgan Hill CA 95037 

58361 General Instrument Corp Optoelectronics 

Div 

3400 Hillview Ave Palo Alto CA 94304 

58377 National Electronics 11731 Markon Dr Garden Grove CA 92641 

58684 Magnetec Corp 61 W Dudleytown Rd Bloomfield CT 06002 

58756 CTS Corp Electromechanical Div 1142 W Beardsley Ave Elkhart IN 46514 

58758 Zambre Co Inc 2134M Old Middlefield Way Mountain View CA 94043-2404 

58900 Giga-tronics Inc 4650 Norris Canyon Road San Ramon CA 94583 

59124 KOA Speer Electronics Inc Bolivar Dr PO Box 547 Bradford PA 16701 

59365 Metelics Corp 975 Stewart Dr Sunnyvale CA 94086 

59660 Tusonix Inc 2155 N Forbes Blvd #107 Tucson AZ 85745 

59942 AVX Filters Corp 11144 Penrose St Sun Valley CA 91352 

59980 Midwest Polychem Ltd 1502 N 25th Ave Melrose Park IL 60160 

6A566 Tecknit Corp 320 North Nopal St Santa Barbara CA 93103 

6V806 

Frammar Mfg Inc (formerly Omni Spectra 

Corp) 

6859 Tujunga Ave North Hollywood CA 91605 

6Y341 Microwave Technology Inc 4268 Solar Way Fremont CA 94538 

60393 Precision Resistive Products 655 Main St Mediapolis IA 52637 

60395 Xicor Inc 851 Buckeye Ct Milpitas CA 95035 

60450 Microwave Components Inc 7 Meehan Dr Chelmsford MA 01824 

60583 Narda Microwave Corp 11040 White Rock Rd Suite 200 Rancho Cordova CA 95670 

60644 CSDC PO Box 2116 Wayne NJ 07470 

61104 Aris Engineering Corp 30 Bond St Haverhill MA 01830 

61429 Fox Electronics Inc 5570 Enterprise Pky Ft. Myers FL 33905 

61485 Hitachi Denshi America Ltd 175 Crossways Park W Woodbury NY 11797 

61529 Aromat Corp 629 Central Ave New Providence NJ 07974 

61638 Advanced Interconnections 5 Energy Way West Warwick RI 02893 

61772 Integrated Device Technology 3236 Scott Blvd PO Box 58015 Santa Clara CA 95052 

61802 Toshiba International 13131 West Little York Rd Houston TX 77041 

61964 Omron Electronics Inc 1E Commerce Schaumburg IL 60173 

62277 Atlas Wire and Cable Corp 133 S Van Norman Rd Montebello CA 90640 

62331 Krytar Inc 1292 Anvilwood Ct Sunnyvale CA 94086 

62559 Schroff Inc 170 Commerce Dr Warwick RI 02886 

62643 United Chemicon Inc 9806 Higgins St Rosemont IL 60018 

63058 McKenzie Socket Technology Inc 44370 Old Warm Springs Blvd Fremont CA 94538 

63132 Time Microwave 398 Martin Ave Santa Clara CA 95050 

63345 Overland Products Co Inc 1687 Airport Rd Fremont NE 68025 

63468 Electro Dynamics 5625 Foxridge Dr Shawnee Mission KS 66201 

63542 Hall-Mark Electronics Corp 11333 Pagemill Rd Dallas TX 75243 

64135 Filter Concepts 2624 S Rousselle St Santa Ana CA 92707 

64155 Linear Technology Corp 1630 McCarthy Blvd Milpitas CA 95035 

64671 Inmet Corp 300 Dino Dr Ann Arbor MI 48103 

64859 AP Products Inc 9325 Progress Parkway Mentor OH 44061 

65032 Rogers Corp PO Box 700 Chandler AZ 85224 

65449 Amtex Intl Inc 1878 Star Batt Rochester MI 48063 

65517 Ayer Engineering Co 1250 West Roger Rd Tucson AZ 85705 

65664 Catamount Mfg Inc 158 Governor Dr PO Box 720 Orange MA 01364 

65940 Rohm Corp 8 Whatney Irvine CA 92714 



Parts Lists 


65964 EVOX-RIFA Inc 100 Tri-State Intl. Suite 290 Lincolnshire IL 60069 

66039 Kaycor International 1732 Central St Evanston IL 60201 

66148 Fairlane Fluid/Air Products 23435 Industrial Park Dr Farmington MI 48024 

66449 Microsource Inc 1269 Corporate Center Pky Santa Rosa CA 95407 

66466 Standard Instrumentation Inc 3322 Pennsylvania Ave Charleston WV 25302 

66544 Continental Microwave & Tool Co 10 Merrill Industrial Dr Hampton NH 03842-0998 

66579 Waferscale Intergraton 47280 Kato Rd Fremont CA 94538 

66958 SGS Semiconductor Corp 7117 E 3rd Ave Scottsdale AZ 52251 

67297 Herotek Inc. 222 N Wolfe Rd Sunnyvale CA 94086 

68459 River Run Enterprises Inc 2001 Jefferson Davis Ave Selma AL 36701 

68630 Tadiran Electronics Industries Inc 3000 Dundee Rd Northbrook IL 60062 

7E222 Littlefuse Tracor Inc 800 E Northwest Hwy Des Plaines IL 60016 

7E585 Zero Mfg 777 Front St Burbank CA 91303 

7M800 Analog Devices Inc 2444 Moorpark Ave San Jose CA 95128 

7U905 Seastrom Inc 2351 Kentucky Ave Indianapolis IN 46241-4827 

7W263 Huber and Suhner Ltd Tumbleinstrass 20 Pfaffikon Switz CH-8330 

70364 American Electric Switch Corp Route 4 Rocky Hill Hwy Lancaster SC 29720 

70903 Belden Corp 200 South Batavia Ave Geneva IL 60134 

71034 Bliley Electric Co 2545 W Grandview Blvd Erie PA 16508 

71218 Bud Industries 4605 E 355th St Willoughby OH 44094 

71450 CTS Corp 1201 Cumberland Ave West Lafayette IN 47906 

71468 ITT Corp ITT Cannon Div 666 E Dyer Rd Santa Ana CA 92702 

71785 Labinal Components and Systems Inc 1521 Morse Ave Elk Grove Village IL 60007 

72259 Nytronics Inc 475 Park Ave South New York NY 10016 

72982 Murata Erie North America Inc 645 West 11th St Erie PA 16512 

73138 Beckman Industrial 4141 Palm St Fullerton CA 92635 

73734 Federal Screw Products Inc 3917 N Kedzie Ave Chicago IL 60618-3415 

74840 Illinois Capacitor Inc 3757 W Touhy Ave Lincolnwood IL 60645 

74970 Johnson E F Co 299 10th Ave South West Waseca MN 56093 

75263 Keystone Carbon Co Inc 1935 State St St Marys PA 15857 

75332 Kings Electronics Co Inc Brooklyn NY (relocated; see CAGE 91836) 

75378 CTS Knights Inc 400 Reimann Ave Sandwich IL 60548 

75915 Tracor Littlefuse Inc 800 East Northwest Hwy Des Plains IL 60016 

78553 Eaton Corp Engineered Fasteners Div 14701 Detroit Ave Lakewood OH 44107-4101 

79963 Zierick Mfg Co Radio Circle Mt Kisko NY 10549 

8B649 Intel Corp 3065 Bowers Ave Santa Clara CA 95051 

8E631 Solitron-MIC Port Salerno FL (relocated; see CAGE 95077) 

8G639 Wavecom Sunnyvale CA 94086 

8K805 Omni Spectra Inc Los Altos CA 

8Z313 LMS Electronics 34101 Monroe Rd Charlotte NC 28205 

81073 Grayhill Inc 561 Hillgrove Ave La Grange IL 60525 

81312 Winchester Electronics 400 Park Rd Watertown CT 06795 

81349 Military specification promulgated by military departments/agencies under authority of Defense Standardization 

Manual 4120 3-M 

81703 Mulberry Metal Products Inc 2199 Stanley Terrace Union NJ 07083 

81774 Carol Wire and Cable Corp 249 Roosevelt Ave Pawtucket RI 02860 

82152 Transco Products Inc 4241 Glenco Ave Marina Del Ray CA 90295 

82199 Polarad Electronics Inc 5 Delaware Drv Lake Success NY 11042 

82877 Rotron Inc 7 Hasbrouck Lane Woodstock NY 12498 

83330 Kulka Smith Inc 1913 Atlantic Ave Manasquan NJ 08736 

84084 American Iron and Machine Work 720 Industrial Blvd Oklahoma City OK 

84171 ARCO Electronics 400 Moreland Rd Commack NY 11725-5707 

84411 American Shizuki Corp 301 W O St Ogallala NE 69153 

86797 Rogan Corp 3455 Woodhead Dr Northbrook IL 60062 





88245 Winchester Electronics 13536 Saticoy St Van Nuys CA 91409 

89110 Amp Inc 1595 South Mt Joy St Elizabethtown PA 17022 

9B003 

Dynamics Corp of America Electronics 

Systems Div 

Encino CA 

9W826 EZ Form Cable Corp 315 Peck St Bldg 24 New Haven CT 06513 

9Z397 Fujitsu Component of America Inc 3320 Scott Blvd Santa Clara CA 95054-3101 

90201 Mallory Capacitor Co 4760 Kentucky Ave Indianapolis IN 46206 

91303 KOL Inc St Paul MN 

91506 Augat Inc 452 John Dietsch Blvd Attleboro Falls MA 02763 

91637 Dale Electronics Inc 1122 23rd St Columbus NE 68601-3632 

91662 Elco Corp Industrial Park Huntington PA 16652 

91833 Keystone Electronics Corp 31-07 20th Rd Astoria NY 11105 

91836 Kings Electronics Co Inc 40 Marbledale Road Tuckahoe NY 10707-3420 

92194 Alpha Wire Corp 711 Lidgerwood Ave Elizabeth NJ 07207 

93459 Weinschel Engineering Co 1 Weinschel Lane Gaithersburg MD 20877 

94696 Magnecraft 1910 Techny Rd Northbrook IL 60062 

95054 Sermax Corp Milwaukee WI 

95077 Solitron Devices Inc Solitron/Microwave Div 1177 Blue Heron Blvd Bldg 2 Riviera Beach FL 33404 

95146 Alco Electronics Products Inc 1551 Osgood St North Andover MA 01845 

95275 Vitramon Inc Box 544 Bridgeport CT 06601 

95348 Gordos Arkansas Inc 1000 N 2nd St PO Box 824 Rogers AR 72757 

95987 Weskesser Co Inc 727 West Glendale Ave Milwaukee WI 53209 

96341 Microwave Associates Inc NW Industrial Park S Ave Burlington MA 01803 

96733 San Fernando Electric Mfg Co 1501 First St San Fernando CA 91341 

98291 ITT Sealectro 585 E Main St New Britain CT 06051 

99800 American Precision Industries Inc Delevan 270 Quaker Rd East Aurora NY 14052-2114 

Div 

99899 Narda Microwave/Loral Corp 435 Moreland Rd Hauppage NY 11788 



8 

Diagrams 


Diagrams for the following assemblies and circuits are included in this chapter: 

Table 8-1. Series 8500A Diagrams 

Reference 

Designation 

Description 

No. of 

Sheets 

Drawing 

Number 

Rev. 

Level 

Page 

Number 

Model 8501A/8502A Peak Power Meter 2 20522 C 8-3 

A1 Interconnect PC Assembly 1 16932-001 G 8-5 

A1 Interconnect Circuit Schematic 3 21088 A 8-6 

A2 Power Supply PC Assembly 1 16995 G 8-9 

A2 Power Supply Circuit Schematic 2 16996 E 8-10 

A3 GPIB/Cal Control PC Assy 1 21014 C 8-12 

A3 GPIB/Cal Control Circuit Schematic 2 21015 D 8-13 

A4 CPU PC Assy 1 16878 E 8-15 

A4 CPU Circuit Schematic 2 16879 C 8-16 

A5 Digital Delay PC Assy 1 16685 U 8-18 

A5 Digital Delay Circuit Schematic 3 16686 H 8-19 

A6/A7 Analog PC Assy 1 20741 M 8-22 

A6/A7 Analog Circuit Schematic 3 20742 N 8-23 

A8 Front Panel Interface PC Assy 1 20195 D 8-26 

A8 Front Panel Interface Circuit Schematic 3 20196 E 8-27 

A9 Front Panel PC Assy 1 20526-001 A 8-30 

A9 Front Panel Circuit Schematic 1 20527 1 8-31 

A12 1 GHz Calibrator Assy 1 20055-001 B 8-32 

A12 1 GHz Calibrator Schematic 1 17097 K 8-33 

8.2 Applicability 

The component assemblies and circuit schematics in this chapter are valid for both Model 8501A and 

Model 8502A. The 8501A has only one channel, therefore all references to Channel B in the assembly 

and circuit diagrams pertain only to the 8502A. Parts lists for all assemblies are contained in Chapter 7. 

Parts lists for options, when applicable, will be in Appendix E. 






A 

Summary of Commands 

A.1 Introduction 

This appendix provides a summary of the commands required to activate all of the various functions of 

the Series 8500A Peak Power Meters (PPM). The commands are listed for each of the different modes of 

operation of the PPM (All, CW, Peak, Graph, Dual Channel, and 1018B Emulation). 

A laminated Quick Reference card is included with the Series 8500A manuals. This card shows all of the 

functional commands in each testing mode as well as how to get from one mode to another. The reverse 

side of the card gives a quick reference to all of the major menus shown in Appendix B. 

Keys that are to be pressed for the command sequence are enclosed in brackets. For simplicity, values are 

given as a single command rather than as individual numbers (for example, 0.1 is shown as [0.1] rather than 

[0][.][1]). The [UNITS] command at the end or included with some of the command keystroke sequences 

means to press any of the three units keys (ms, µs, or ns) to enter the values of the keyed sequence. 

Numbers in parenthesis after a MENU or MEM key means to press the key that number of times to reach 

a specific menu level. 

A.2 Commands Applicable to All Modes 

Function 

Auto Zero Detectors 

Calibrate Detectors 

Self-Test the PPM 

Detector Offset (Channel A) 

Detector Offset (Channel B, 

8502A only) 

Frequency Correction 

Change Frequency Correction 

to User Freq/PROM 


to V/GHz/PROM 


to Cal Factor (dB) 

Change Display Units Between 

dBm and mW 

Hide/Display Frequency 

Information 

Command Sequence 

[MENU] (1) [F3] [F2] 

[MENU] (1) [F3] [F1] 

[MENU] (11) [F2] 

[MENU] (3) [F1] [sn.nn] [dB] 

[MENU] (3) [F2] [sn.nn] [dB] 


[MENU] (3) [F3] [F1] [nnn.nnn] [GHz] 

[MENU] (3) [F3] [F2] [vv.vv] [UNITS] [ss.ss] [UNITS] [ff.ff] [GHz] 

[MENU] (3) [F3] [F3] [A] or [B] [sn.nn] [dB] 

[MENU] (4) [F3] (toggle) 

[MENU] (7) [F3] 

(toggling occurs by pressing MENU seven times after hiding or displaying 

frequency) 

Manual No. 20790, Rev C, November 1998 A-1 



Function 


Review Detector PROM 

Information [MENU] (10) [F2] (for A) or [F3] (for B) 

Check Date and Time then Exit 

Change Date and Time then Exit 

Set Max and Min Power Limits 

Frequency or Cal Factor or 

V/GHz 

Recall Setup in Memory (n) 

Store Setup in Memory 

Recall Power-On Setup 

Display Current Setup 

Display Power-On Setup 

Display Setup in Memory 

Reinitialize Current Setup 

Reinitialize All But Current Setup 

Reinitialize a Numbered Setup 

(nn) 

A.3 CW Mode Commands 

[MENU] (5) [F3] [F3] 

[MENU] (5) [F3] [F1] [mmddyy] [UNITS] [hhmmss] [UNITS] [F3] 

[MENU] (7) [F1] [nn.nn] [UNITS] [nn.nn] [dBm] 


[MEM] (1) [F1] [n] [UNITS] 

[MEM] (1) [F2] [n] [UNITS] 

[MEM] (1) [F3] 

[MEM] (2) [F1] [F1] or [F3] (F1 = more, F3 = exit) 

[MEM] (2) [F2] [F1] or [F3] (F1 = more, F3 = exit) 

[MEM] (2) [F3] [nn] [UNITS] [F1] (more) or [F3] (exit) 

[MEM] (3) [F1] 

[MEM] (3) [F2] 

[MEM] (3) [F3] [nn] [UNITS] 

Function 

Select CW Mode 

CW Averaging 



[CW] 


[MENU] (10) [F1] 

A.4 Peak Mode Commands 

Function 

Select Peak Mode 

Select 8501A Internal Trigger 

and Level 


and Level 




Enable Cursor Delay 

Disable Cursor Delay 




[PEAK] 

[MENU] (1) [F1] [nn.nn] [dBm] [mW] 

[MENU] (1) [F1] [A] or [B] [nn.nn] [dBm] [mW] 

[MENU] (1) [F2] 

[MENU] (10) [F1] 


[↑] or [↓] 

[UNITS] 

[MENU] (4) [F1] (for ch A) or [F2] (for ch B) [nn.nn] [UNITS] 

[MENU] (4) [F1] (for ch a and/or [F2] for ch b of the 8502A) [0] [UNITS] 

A-2 Manual No. 20790, Rev C, November 1998 



A.5 Graph Mode Commands 

Function 

Select Graph Mode (from 

single channel operation only) 

Autoscale 


and Level 


and Level 





GPIB Plot (Paper) 

GPIB Plot (Transparency) 

Code Number Entry for Plot 

Part Number Entry for Plot 

Abort (Stop) Plotting Activity 

Enter Plotter GPIB Address 

Set Initial Delay for 

Autoscaling (normal PPM 

operation) 

Set Averaging Value for 

Autoscaling (normal PPM 

operation) 


[GRAPH] 

[AUTOSCALE] 

[MENU] (1) [F1] [nn.nn] [dBm] [mW] 

[MENU] (1) [F1] [A] or [B] [nn.nn] [dBm] [mW] 

[MENU] (1) [F2] 


[MENU] (4) [F1] (for ch A) or [F2] (for ch B) [nn.nn] [UNITS] 

[MENU] (4) [F1] (for ch A) or [F2] (for ch B) [0] [UNITS] 

[MENU] (2) [F3] [F1] 

[MENU] (2) [F3] [F2] 

[MENU] (5) [F1] [nnnn] [UNITS] (nnnn = up to 12 digits) 

[MENU] (5) [F2] [nnnn] [UNITS] (nnnn = up to 12 digits) 

[MENU] (6) [F1] 




*Set Initial Delay 

for Autoscaling 

(1018B emulation operation) [MENU] (11) [F2] [nn.nn] [UNITS] 

*Set Averaging Value 

for Autoscaling 

(1018B emulation operation) [MENU] (11) [F3] [nnn] [UNITS] 

*Valid only after 1018B Emulation has been entered 

A.5.1 

A.5.2 

Change Between Cursor, Marker, and Pulse Sub-Modes 

PULSE/CURSOR/MARKER 

Triple toggle 

Cursor Sub-Mode Commands 

Function 

Change Start Delay Move 

cursor to STRT DLY line on 

display, enter change using 

Change Window Delay Move 

cursor to DLY WIND line on 



[nn.nn] [UNITS] or spin knob 





Change Cursor Delay Move 

cursor to CSR DLY line on 


Change Internal Trigger Level 

Move cursor to TRG LEV line 

on display, enter change using 

Change Reference Power 

(100% Point) Move cursor to 

REF PWR line on display, 

enter change using 


[nn.nn] [UNITS] (or spin knob), or use 


[nn.nn] [UNITS] 

A.5.3 

A.5.4 

Pulse Sub-Mode Commands 

Function 

Change Pulse Width Start and 

End Percentages Move cursor to 

PULSE WID line 

Change Rise Time Start and 

End percentages Move cursor 

to RISE TIME line on display 

Change Fall Time Start and 

End Percentages Move cursor 

to FALL TIME line on display 

Marker Sub-Mode Commands 

Function 


Move cursor to MRKR 2-1 line 

on display 



on display 



on display 


Move cursor to 4th line on 

display 






[snn.n] [UNITS] 




NOTE: Entering nn.n (positive) places the marker on the rising edge. Entering -nn.n (negative) places the marker on the falling edge. 




A.6 Dual Channel Operation 

A.6.1 

A.6.2 

CW Mode Commands 

From Initial Power-On select 

Peak Mode Commands 

Assuming that there is an 

Autoscalable pulsed signal 

greater than the current trigger 

level at the channel A detector 

input, from initial Power-On 

select: 

[cw] [B] 

If the Dual Channel state is being entered from some other state, use the channel A 

and B keys. When both A and B keys are lit, the Dual Channel state has been 

activated. 

[GRAPH] [AUTOSCALE ...PEAK] [B] 

This method uses the Graph Mode to ensure that the cursor is placed on the pulse 

measured by channel A. 

The [GRAPH] [AUTOSCALE] keystrokes can be omitted, but this method does 

not guarantee that the cursor will be placed on the pulse. To find the pulse, use the 

procedures outlined in Method 1 of the Peak Power Measurements in Chapter 6. 

A.6.3 

A.6.4 

Other Dual Channel Commands 


Display Ratio A/B Power Mode 

Select Peak Mode for Channel A 

Select CW Mode for Channel A 

Select Peak Mode for Channel B 

Select CW Mode for Channel B 

Exit Ratio Mode 

[MENU] (3) [F2] [nn.nn] [dB] 

[MENU] (7) [F2] 





[CW] or [PEAK] 

IEEE & 1018B Emulation Commands 

Select PPM Listen and Talk 

Address 

Initiate 1018B Emulation Mode 

Disable/Enable Service Request* 

Automatic/Bus Command 

Trigger Reset* 

Get Data Fast (No EL Display)* 

Set Measurement Range* 

End 1018B Emulation Mode* 


[MENU] (8) [F2] 

[MENU] (8) [F1] (toggle) 

[MENU] (8) [F2] 

[MENU] (8) [F3] 

[MENU] (9) [F1] (for nnn.n µW) 

[MENU] (9) [F2] (for nn.nn mW) 

[MENU] (9) [F3] (for n.nnn mW) 

[MENU] (10) [F2] 

* Valid only after initiating 1018B Emulation Mode. 






B 

Menu and Memory Keys 

B.1 Introduction 

This appendix is a quick reference to the menus that can be accessed through the MENU and MEMory 

keys. The number in parenthesis after the key is the number of times the key must be pressed to reach the 

designated menu. MENU (1) means to press the key one time; MENU (2) means to press the key two 

times, etc. 

The key display information in this appendix is duplicated on the laminated Quick Reference card 

shipped with the manual. The opposite side of the card contains a Summary of Commands described in 

Appendix A. 

Two levels of menu displays are available. The first level includes menus for normal 8500A functions. 

The second level are the menus used during 1018B emulation. MENU (8) in the normal mode enables or 

toggles the 1018B Emulation mode. 

B.2 MENU Key Displays 

B.2.1 

Normal 8500A Functions 

Keystrokes 

MENU (1) 


Menu = NEXT MENU 

F1 set Int Trig and Level 

F2 set Extrn Trigger 

F3 to Cal or Zero Detectors 

MENU (2) 


F1 to Enter CW Averaging Number 

F2 to Enter Peak Averaging Number 

F3 for GPIB Plot 

MENU (3) 


F1 to Enter Detector A Offset 

F2 to Enter Detector B Offset 

F3 to Enter Source of Frequency Correction 

NOTE: F2 does not apply to the Model 8501A 

Manual No. 20790, Rev C, November 1998 B-1 



MENU (4) 


F1 to Enter Detector A Ref Delay 

F2 to Enter Detector B Ref Delay 

F3 to Select mW Format 


MENU (5) 


F1 to Enter Code Number 

F2 to Enter Part Number 

F3 for Read and Set Time 

MENU (6) 

Menu = NEXTR MENU; Minus = PREV MENU 

F1 to Abort Current Plotting Activity 

F2 to Enter Plotter Address 

F3 to Enter 8500A Listen and Talk Address 

MENU (7) 


F1 to Set Max and Min Power Limits 

F2 to Select Ratio Display Mode 

F3: Hide (or Display) Frequency Information 


MENU (8) 


F2: Emulate 1018B 

MENU (9) 


F1 to Program Detector PROM 

F2 to Set Initial Dly Value for Autoscaling 

F3 to Set Averaging Value for Autoscaling 

NOTE: The MENU (9) F1 function is designed to be used only in conjunction with 

the Giga-tronics PROM Programming Accessory Kit 

If F1 is pressed without any requirement for using the PROM programming device, 

a long series of sub-menus must be stepped through to escape from the routine. To 

circumvent this, press the RESET button on the rear of the instrument to escape 

back to the last measurement mode. 

MENU (10) 


F1 for Fast Analog Output 

F2: Review A Detector PROM 

F3: Review B Detector PROM (8502A only) 

B-2 Manual No. 20790, Rev C, November 1998 


Menu and Memory Keys 

MENU (11) 

Minus = PREV MENU 

Be Sure No RF is Applied to Detector 

Press CLEAR to Skip All Tests 

F1 for Service Fncts 

F2 for Self Test 

B.2.2 

1018B Emulation Mode Functions 

MENU (8) 

1018B Emulate Mode, Bus Trigger Reset, SRQ Enabled 


SUB-MENU (8) 

F1 to Disable SRQ (Service Request) 

F2 for Automatic Trigger Reset 


1018B Emulate Mode, Auto Trigger Reset, SRQ Disabled 


F1 to Enable Service Request 

F2 for Bus Command Trigger Reset 


NOTE: Pressing [MENU] (8) [F1] and then [MENU] (8) again will enable SRQ; 

other SUB-MENU (8) items remain the same. Pressing [MENU] (8) [F2] and then 

[MENU] (8) again will change Automatic Trigger to Bus Command in SUB-MENU 

(8). All other SUB-MENU (8) commands remain the same. 

MENU (9) 


Current Range Value is X 

F1 for Range 1 (XXX.X µW) 

F2 for Range 2 (XX.XX mW) 

F3 for Range 3 (X.XXX mW) 

MENU (10) 


Press MENU for next lower level menu 

F2 to end 1018B Emulation 

MENU (11) 

MENU (12) 

MENU (13) 

1018B Emulate mode only. Same as MENU (8) for the normal 8500 mode. 



Manual No. 20790, Rev C, November 1998 B-3 



B.3 MEMory Key Displays 

The following menus are activated by repeatedly pressing the MEM key. MEM (1) indicates to press the 

key once. MEM (3) indicates to press the MEM key three times. 

MEM (1) 

Press [MEM] for additional selections 

F1 to Recall Setups 

F2 to Store Setups 

F3 to get Power-On Setup 

MEM (2) 

Press [CLEAR] to return to data display 

F1 to Display Current Setup 

F2 to Display Power-On Setup 

F3 to Display a Numbered Setup 

MEM (3) 

Press [CLEAR] to return to data display 

F1 to Initialize the Current Setup 

F2 to Initialize All but Current Setup 

F3 to Initialize a Numbered Setup 

B-4 Manual No. 20790, Rev C, November 1998 


C 

Display Formats 

C.1 General 

This appendix illustrates the major display formats that will be presented in each operating mode. The 

front panel function keys are illustrated that will produce the corresponding display. Darkened keys in the 

following illustrations will be turned on to produce the corresponding display at the left. 

C.2 Data Displays 

MODE DATA DISPLAY MODEL 8501A MODEL 8502A 

CHANNEL A 

CW MODE 

CHANNEL A 

PEAK MODE 

CHANNEL A 

GRAPH MODE 

Model 8502A channel B displays are same as above, except with the B key turned on and B: shown on the display. 

DUAL CHANNEL 

CW MODE 

NA 

Manual No. 20790, Rev C, November 1998 C-1 



MODE DATA DISPLAY MODEL 8501A MODEL 8502A 

DUAL CHANNEL 

NA 

PEAK MODE 

DUAL CHANNEL 

NA 

RATIO MODE 

(A = PK Signal) 

(B = PK Signal) 

For ratio’ing various types of signals to each other, the indication in the lower right corner would be: 

A = Peak; B = CW = PK/CW: Both A & B = CW = CW/CW: A = CW; B = Peak = CW/PK 

ANY MODE 

Error Indicated 

Display Blank or Frozen 

No Trigger Occurring 

Ready = ON 

New Data = OFF 

Ready = ON 

New Data = OFF 

SELECT 

NA 

A OR B 

CHANNEL 

OR 

C-2 Manual No. 20790, Rev C, November 1998 


D 

RF Detectors 

D.1 Introduction 

The detectors used with the Series 8500A Peak Power Meters (PPM) are dual diode. They contain a 

preamplifier/line driver, a correction PROM with an address counter, and a thermistor to measure the 

temperature of the detector mounting. Since diode detection is used, there is an inherent non-linearity that 

must be compensated before the detector can be used for power measurements. Compensation is done 

automatically by a special calibration routine performed by the PPM that steps the power output of an 

internal RF source from -30 dBm to +20 dBm, and then records the resultant output voltage of the 

detector at each step. A conversion table is automatically calculated and stored in non-volatile RAM so 

that the detectors will remain calibrated when the PPM is turned off and back on again. This process 

takes less than a minute and can be performed at any time. 

The detectors are either high or low speed. The high speed has a rise time of 15 ns and a minimum 

frequency of 750 MHz for accurate measurements. The low speed detector has a rise time of 750 ns and a 

minimum frequency of 30 MHz. The difference between the two is totally in the diode element. The low 

speed element contains an additional filter capacitor that slows the pulse response time and allows lower 

RF frequency operation. 

The diode element is field replaceable. After replacement, the correction PROM must be replaced with 

one that has been programmed with the diode’s new video resistance and frequency characteristics. 

Manual No. 20790, Rev C, November 1998 D-1 



D.2 Detector Specifications 

Det. 

Model 

Frequency 

Range 


Range 

Max. Power 

(Peak or Avg) 

Maximum 

VSWR 

RF 

Conn 

HIGH SPEED — 15 ns 

16936 750 MHz to 

18.5 GHz 

-20 dBm to +20 dBm (Pulse) 

-40 dBm to +20 dBm (CW) 

+23 dBm (200 mW) 

(Damage Limit) 

1.12: 750 MHz to 2 GHz 

1.22: 2 to 12.4 GHz 

1.37: 12.4 to 18 GHz 

Type N 

(m) 

16937 750 MHz to 

18.5 GHz 



+23 dBm (200 mW) 


1.12: 750 MHz to 2 GHz 

1.22: 2 to 12.4 GHz 

1.37: 12.4 to 18 GHz 

APC-7 

(mm) 

17266 750 MHz to 

26.5 GHz 



+23 dBm (200 mW) 


1.12: 750 MHz to 2 GHz 

1.22: 2 to 12.4 GHz 

1.37: 12.4 to 18 GHz 

1.50: 18 to 26.5 GHz 

Type K 

(m) 

17071 750 MHz to 

40.0 GHz 



+23 dBm (200 mW) 


1.12: 750 MHz to 2 GHz 

1.22: 2 to 12.4 GHz 

1.37: 12.4 to 18 GHz 

1.50: 18 to 26.5 GHz 

1.92: 26.5 to 40 GHz 

Type K 

(m) 

LOW SPEED — 750 ns 

16934 30 MHz to 

18.5 GHz 



+23 dBm (200 mW) 


1.12: 30 MHz to 2 GHz 

1.22: 2 to 12.4 GHz 

1.37: 12.4 to 18 GHz 

Type N 

(m) 

16935 30 MHz to 

18.5 GHz 



+23 dBm (200 mW) 


1.12: 30 MHz to 2 GHz 

1.22: 2 to 12.4 GHz 

1.37: 12.4 to 18 GHz 

APC-7 

(mm) 

17267 30 MHz to 

26.5 GHz 



+23 dBm (200 mW) 


1.12: 30 MHz to 2 GHz 

1.22: 2 to 12.4 GHz 

1.37: 12.4 to 18 GHz 

1.50: 18 to 26.5 GHz 

Type K 

(m) 

1. The dimensions and weight are identical for all detectors: 

Length = 133 mm (5.25 in) 

Diameter = 37 mm (1.44 in) 

Weight = 0.3 kg (0.7 lbs) 

Frequency Range: 

High Speed: 

Low Speed: 

750 MHz to 18.5 GHz 



(High speed detectors can be used down to 500 MHz.) 



Rise Time: 

High Speed: 

Step Response: 

Low Speed: 

RF Detectors 

Absolute Maximum 

(Peak or Avg): 

+23 dBm (200 mW) 


Return Loss (SWR): 

Type N, APC-7 

Type K 

Below 2 GHz 25 dB (1.12) 25 dB (1.12) 

2 to 12.4 GHz 20 dB (1.22) 20 dB (1.22) 

12.4 to 18 GHz 16 dB (1.37) 16 dB (1.37) 

18 to 26.5 GHz 14 dB (1.50) 

26.5 to 40 GHz 10 dB (1.92) 

Calibration Factor Uncertainty: 

Frequency Sum of Uncertainties (%) 1 Probable Uncertainties (%) 2 

Below 10 GHz 2.6% 1.2% 

10 to 18 GHz 6.4% 3.7% 

18 to 26.5 GHz 10% 6.5% 

26.5 to 40 GHz 20% 10% 

NOTES: 

1. Includes uncertainty of reference standard and transfer uncertainty. Directly traceable to NIST (formerly NBS). 

2. Square root of the sum of the individual uncertainties squared (RSS). 




D.3 Electrical Description 

D.3.1 

Preamplifier PC Assembly 

Refer to Figure D-2 

The circuitry on this PC board is used to amplify the voltage produced when the detected RF power has 

been converted to dc. The circuit is similar to a two stage operational amplifier with the non-inverting 

input at the base of Q2 and the inverting input at the base of Q1 (see Figure D-2). 

The overall gain of the circuit is set by the ratio of R1 to R5 and R2 to R3. C9 is the compensation 

capacitor. R26 provides the match to the cable impedance. The output for the circuit can be measured 

between TP2 (DET Pulse), and TP1 (ground). 

The first stage of the amplifier is formed by transistors Q1 through Q6. Q3 and Q4 form a constant 

current source which sets the current that is drawn through the first stage. C1 and C2 are used to AC 

couple the signal to Q1 and Q2, the input devices of the amplifier. Q5 and Q6 provide high impedances 

which are driven by Q1 and Q2. The gain of the first stage is set by the ratio of R34 and R33 to R11. R9 

and C3 provide adjustments to optimize the step response of the amplifier. U1 is a low offset and low 

bandwidth op-amp that provides the DC signal path by controlling the current through Q6. 

Figure D-1. Op-Amp Equivalent of Pre-Amp Circuit 

The second stage of the amplifier is formed by Q7 through Q10. Q9 and Q10 provide a constant current 

source for the second stage of the amplifier. Q7 and Q8 form a differential amplifier. The gain of the 

second stage is set by the ratio of R18 and R19 to R24. 

Q11 is an emitter follower to drive the necessary high currents required by the circuit. 

The difference between the low speed and high speed detectors is diode element. The high speed detector 

has a very small output capacitance, which produces a rise time of 15 ns while the low speed detector has 

a large output capacitance to produce a 750 ns rise time. This causes a change in the minimum frequency 

at which the detector can accurately convert RF power to dc voltage. 

D-4 Manual No. 20790, Rev C, November 1998 


RF Detectors 

Figure D-2. Pre-Amplifier/Line Driver Schematic 




D.3.2 

PROM PC Assembly 

Refer to Figure D-3 

The other PC board located in the detector housing contains the PROM and its associated driver. The 

fusible link PROM contains RF calibration data for the specific diodes used in the detector. This data 

includes the serial number, type, date and place of calibration, and frequency response correction 

information. The PROM is read four bits at a time by addressing it with the 12 bit counter, U1. The 

PROM cannot be erased. If the response data changes, the PROM must be removed and replaced with a 

new one. It must be programmed externally since the PPM by itself has no programming ability. 

However, Giga-tronics offers an optional PROM Programmer Accessory Kit, #16976, which works in 

conjunction with the PPM to reprogram the PROM. 

The thermistor RT1 measures the temperature of the diode mount to correct for the temperature 

dependence of the diodes in the detector. 

Figure D-3. PROM PC Assembly Schematic 



RF Detectors 

D.4 Detector Maintenance 

There is no regular maintenance required for the detectors. It might become necessary to open the 

detector mount to correct a fault either in the diode element or in the amplifier/PROM circuit, or to 

replace the PROM. 

D.5 Detector Troubleshooting 

The most common cause of failure is the application of too much power, which may destroy the diode 

element. This will most likely result in the detector failing to autocalibrate. Since there are several faults 

that can cause the calibration routine of the PPM to fail, it is recommended that you have an 

understanding of the calibration process, described in Chapter 2 of the Series 8500A manual. 

Understanding the calibration process allows you to narrow the number of fault possibilities if the history 

of the detector is unknown. If the detector has been connected to a source of power in excess of +23 dBm 

(200 mW), an autocalibration should be performed before further use. If the detector fails this process, it 

should be removed from service until a new diode element has been installed and the unit recalibrated. 

If a component in the preamplifier/line driver fails, the detector will also fail autocalibration. To verify 

that the problem is in the amplifier and not the diodes, a measurement of the voltage can be performed by 

first removing the outer cover from the detector (see Disassembly of the Detectors in Section D.5.1). 

Refer to the circuit description and Figure D-2 in order to proceed with troubleshooting. It is best to 

connect the detector to a source of RF power at a level of about 0 dBm to trace the signal level through 

the amplifier. The signal can be pulse modulated if tracing is done with an oscilloscope, or CW if tracing 

is being done with a voltmeter. With no signal applied, the voltage at the output of the amplifier should 

be 0 V ±0.1 mV. The output voltage with 0 dBm applied will typically be about 0.5 V. This reading is 

taken at the emitter of the output transistor, not at the output end of the 75 Ω resistor that feeds the coax 

cable. 

The PROM and address counter circuit is very reliable, but in the event that it does fail, the PPM will be 

unable to correctly read the PROM, and an error message to that effect will be displayed. The most likely 

failure in that case would be a broken wire in the cable or in the connectors at each end of the cable. If a 

PROM read failure occurs, connect the detector to a different channel or to a different PPM. If a failure 

occurs again, it will be necessary to troubleshoot the PROM circuit. After verifying that there are no 

broken wires in the detector, proceed to check the active components. Since the PROM is mounted in a 

socket, the simplest check is to first try a different PROM to determine if the circuit is functioning. It is 

necessary to use a programmed PROM to accomplish this check, such as one from working detector. Note 

that this will produce incorrect RF power readings, but it is otherwise a valid test. 

The other component that can be checked is the thermistor. The thermistor has two purposes. The PPM 

checks the voltage at the thermistor to determine if the detector is present. If the voltage is above 10 V 

the PPM makes the assumption that there is no detector present. If the voltage is in the normal working 

range, the voltage level is converted to a temperature reading which is compared with the temperature of 

the detector when it was last calibrated. If the difference in the two readings is more than 5 degrees 

Celsius, a message will display showing the difference. Therefore if the thermistor is open, possibly due 

to a broken wire, the PPM will not recognize that the detector is connected. If the thermistor has 

somehow been shorted, perhaps due to twisted wires, then it will indicate a very large positive change in 

the temperature reading from the reading taken during calibration. It will also indicate an impossibly 

large temperature on the detector. The resistance of the thermistor should normally measure 10K at 25 °C. 




D.5.1 

Disassembly of Detectors 

Follow these instructions to disassemble a detector (see Figure D-4). 

CAUTION 

The detectors contain CMOS components and are subject to static electricity 

damage. Use correct safety procedures, protective devices and clothing to prevent 

static discharge before opening a detector enclosure. 

1. Remove screws (1) and (2). Take off the sleeve holder plate and slide the sleeve off the cap 

assembly. 

2. Position the detector so that the Pre-Amp assembly (the board with components) is visible. 

Locate the detector element leads. They are on the end of the PC board nearest to the detector 

housing assembly. Remove the solder from the leads of the detector element, and remove the 

leads from the holes in the PC board. Straighten the leads. 

3. Unscrew the detector housing assembly from the cap assembly. Use the wrench flats on the 

housing assembly which are located closest to the cap assembly to remove the housing assembly. 

The detector element will remain attached to the housing assembly. 

If the Spring Washers fall out when the detector housing assembly is removed, they should be 

replaced as shown in Detail A of Figure D-4. 

D.5.2 

Replacement of Detector Element 

These are instructions to replace the detector element (see Figure D-4). A detector element should be 

replaced in the field only if a Giga-tronics Programming Accessory Kit (P/N 16976) is on hand to 

program a new PROM with the characteristics of the new element, and if the required equipment for 

measuring Cal Factor is available. If either or both of the above items are not available, the entire 

detector should be returned to the factory for element replacement. 

The Cal Factor is the frequency response of the detector with respect to the 1 GHz response, expressed in 

dB. If the Cal Factor at 10 GHz is -0.2 dB, it means that the detector output voltage at any applied power 

level is 0.2 dB lower at 10 GHz than at 1 GHz. 

1. Remove the old detector element from the detector housing assembly by pulling the element 

straight out from the Assembly. 

CAUTION 

Do not twist the element as you remove it. Doing so could damage the center 

conductor of the detector housing assembly. 

2. Take the new detector element out of its protective packaging and carefully straighten the leads. 

Do not pull sharply on the leads or they may come off. 

3. Carefully insert the new detector element into the detector housing assembly. Gently push on the 

detector element to press the detector element pin into the center conductor of the detector 

housing assembly. Once the element has been inserted, try gently to pull it back out of the 

housing assembly. If there is resistance, the element is inserted correctly. If the element comes 

out easily, the element has not been correctly inserted into the center conductor. Remove the 



RF Detectors 

detector element, make sure that the center conductor is centered in the housing and then reinsert 

the element. 

CAUTION 

Do not twist the element as you insert it. Doing so could damage the detector 

element pin or the center conductor of the detector housing assembly. 

4. Remove and discard the old PROM. Use the instructions furnished with the PROM Programming 

Accessory Kit to program the new PROM. 

5. Insert the new PROM into the PROM PC board so that pin #1 is in the position marked on the 

PC board (see Figure D-4). 

D.5.3 

Reassembly of Detectors 

Follow these instructions to reassemble the detector (see Figure D-4). 

CAUTION 

Do not twist the detector element while inserting it. This can damage the detector 

element pin or the detector housing assembly center conductor. 

1. Make sure that the detector element leads are straight. Screw the detector housing assembly into 

the cap assembly. Be very careful not to damage the leads of the element. 

2. Insert the element leads into the proper holes in the Pre-Amp board as shown in Detail B of 

Figure D-4. The lead from the center pin goes to hole 1, and the other lead goes to hole 2. Solder 

the leads in place. 

3. After the element has been installed, it may be necessary to readjust the pulse response of the 

amplifier due to a possible difference in the video resistance of the new element diodes in 

relationship to the old element diodes. 

To adjust the pulse response, connect the detector to a pulsed microwave source of about 0 dBm. The 

pulse must be very clean as this procedure assumes a perfect input pulse. The rise time of the pulse must 

be less than 6 ns, and it should have no overshoot or ringing. If the shape of the pulse is not perfect but 

is accurately known, this will do. 

Set the PPM in the Graph mode with the Internal Trigger at -10 dBm. Autoscale the display by pressing 

[GRAPH] and set the window to a width of 0.1 µs. If the pulse shape is wrong, adjust C3 on the 

Pre-Amp board in small increments and wait for the trace on the screen to redraw. After finding an 

optimum setting for C3, adjust R9 until the best shape is obtained. Do not move either control very far 

from the original setting. The end result for this procedure is to set the maximum rise time consistent 

with no overshoot or ringing. If the rise time cannot be set below 15 ns, a small overshoot of less than 

5% is acceptable. 

4. Slide the sleeve onto the cap assembly. Replace the sleeve holder plate. Insert and tighten screws 

(1) and (2), and return the detector to service. 




Figure D-4. Detector Disassembly and Assembly Details 



E 

Options 

E.1 Introduction 

The following options are available for Series 8500A, and are discussed under respective headings: 

Option 01: Rack Mount Kit, 16657 

Option 03: Rear Panel Connections 

Parts lists are included with the applicable option in this appendix. Diagrams for options, when 

applicable, are in Chapter 8. 

E.2 Option 01: Rack Mount Kit 

Option 01 is a 19-inch standard equipment rack mounting kit for the Series 8500A power meter. It 

includes slides and wall mounting brackets. 

16657 OPT 01 RACK MT 5 1/4 (8501/02), Rev: B 


1 12678-002 1 58900 12678-002 SLIDE-RACK SECTIONS (PAIR) 

2 12678-001 1 58900 12678-001 SLIDE-CHASSIS SECTION (PAIR) 

3 10351-001 2 58900 10351-001 ROUND NICKEL HANDLE 

4 20077 1 58900 20077 BRACKET,RACK MOUNT, 5.25 (L) 

5 20078 1 58900 20078 BRACKET,RACK MOUNT, 5.25" (R) 

6 10352 4 58900 10352 HANDLE FERRULE 

7 13854 6 58900 13854 SPACER, .172IDX.500ODX.31LG 

8 20074 1 58900 20074 MOUNTING BLOCK, LEFT 

9 20075 1 58900 20075 MOUNTING BLOCK, RIGHT 

10 10415 1 58900 10415 LABEL, OPTION IDENTIFICATION 

101 10111-005 6 58900 10111-005 8-32 X 5/8 PAN 

102 13603-001 2 58900 13603-001 8-32 X 1/2 FLAT 100 DEG 


104 HBFP-A3206 4 58900 HBFP-A3206 10-32 X 3/8 FLAT 


Manual No. 20790, Rev C, November 1998 E-1 



E.3 Option 03: Rear Panel Connections 

When Option 03 is installed, the Calibrator and Detector connectors are relocated from the front panel to 

the rear panel. 

20794 MODEL 8501A OPTION 03 REV A: 


1 17051-001 1 58900 17051-001 DET. INPUT CABLE ASSY, OPT. 03 

2 17283 1 58900 17283 BRACKET, CLAMP DET INPUT CABLE 

3 HTM0-00003 3 06383 ABMM-A-D CABLE TIE ANCHOR 

4 20508-002 1 58900 20508-002 FRONT PANEL, 8501A-OPT 03 

5 16884 1 58900 16884 LABEL,MISC. 

20795 MODEL 8502A OPTION 03, Rev: B 


1 20510-002 1 58900 20510-002 FRONT PANEL, 8502A OPT03 

2 17051-001 2 58900 17051-001 DET. INPUT CABLE ASSY, OPT. 03 

3 17283 1 58900 17283 BRACKET, CLAMP DET INPUT CABLE 

4 16884 1 58900 16884 LABEL,MISC. 

5 10414-001 1 2R182 864 3 LUG TERMINAL STRIP 

101 HTM0-00003 4 06383 ABMM-A-D CABLE TIE ANCHOR 

102 10384-002 2 95987 F6NY-312NA CABLE CLAMP 5/16"DIA 1/2" WIDE 

E-2 Manual No. 20790, Rev C, November 1998 


Index 

! 

1018B commands 3-38, 3-52 

1018B Emulation 3-38 

1018B Emulation Commands 3-38, 3-52 

1018B features not emulated by the PPM 3-40 

Analog output 3-39 

direct mode 3-39 

Front panel menus 3-39 

Initiating the 1018B emulation mode 2-47 

Mode functions B-3 

Output data modes 3-38 

Output format 3-38 

Over and under range 3-40 

Peak Power Meter Emulation 2-47 

Reference delay, correction of carrier frequency, and 

offset vs Remote state 3-39 

Two detectors 3-39 

A 

A2 Test points 4-3 


A4 Test Points 4-11 


A6/A7 Test points 4-23 

A8 Front panel interface board 5-12 


Address decoding and handshake 4-9 

Analog output 3-39 

Analog output accuracy test 5-7 

Analog PC assembly (A6/A7) 4-20 

Auto-Zero function 2-15 

Automatic functions of the Graph mode 3-24 

Automatic timing measurement commands 3-28 

Automatic window delay selection 

related commands 2-24, 3-26 

Autoscaling procedure 2-19 

Autoscaling procedure, external trigger 2-20 

Autozero detectors commands 3-15 

Auxiliary inputs/outputs 1-5 

B 

Backup battery circuit 4-11 

C 

CAGE 

List of Manufacturers 7-36 

Calibration 

Self-Calibration Procedure 2-14 

Calibration and Testing 5-1 

A8 Front panel interface board 5-12 

Analog output accuracy test 5-7 

Calibrator output level test 5-3 

Calibrator return loss test 5-3 

Delay accuracy test 5-6 

Detector return loss test 5-7 

Equipment Required 5-2 

Initialization 5-12 

Instrument plus power detector linearity test 5-3 

Plotter output/IEEE-488 interface 5-7 

Power linearity test setup 5-4 

Procedures 5-8 

Voltage proportional to frequency test 5-7 

Volume adjust 5-20 

Calibration commands 3-15 

Calibration Procedures 5-8 

Calibrator output level test 5-3 

Calibrator PC assembly (A12) 4-27 

Calibrator return loss test 5-3 

Calibrator specifications 1-5 

Change between cursor, marker, 

and pulse sub-modes A-5 

Cleaning 1-2 

Clock 4-16 

Clock gate 4-16 

Command string format 3-12 

Commands Applicable to All Modes A-1 

Commands for retrieving data from the PPM 3-23 

Commands to output graphic data to a controller 3-33 

Common mode functions 3-15 

Autozero detectors commands 3-15 

Calibration commands 3-15 

Hide and Unhide frequency information 

commands 3-15 

Output status byte information command 3-16 

Power limits 3-16 


Superceded by Revision D, March 2009 

Index-1


SRQ related commands 3-16 

Store or recall setup commands 3-15 

Temperature difference since last 

calibration commands 3-15 

Cooling 1-2 

Counter 4-16 

CPU interface 4-14 

CPU PC assembly (A4) 4-8 


Address decoding and handshake 4-9 

Backup battery circuit 4-11 

Data buffers 4-10 

External memory 4-10 

Interrupt priority decoder 4-10 

Real time clock 4-10 

Reset timer 4-10 

The microprocessor 4-9 

Unbuffered memory 4-10 

Cursor control commands 3-31 

Cursor delay 2-24 

Cursor power 2-24 

Cursor sub-mode commands A-5 

Cursor sub-mode functions 2-24 

Cursor delay 2-24 

Cursor power 2-24 

Delay window 2-24, 3-26 

Reference Power 2-25 

Start delay 2-24 

Trigger 2-25 

CW averaging 2-11 

CW mode 2-11 

CW averaging 2-11 

Frequency 2-11 

Low power level measurement 2-11 

CW Mode Commands A-3 

CW power measurement 2-18 

CW, CW measurements 2-32 

D 

Data buffers 4-10 

Data Formats 3-52 

Default Settings 1-7 

Delay accuracy test 5-6 

Delay board reset latch 4-17 

Delay window 2-24, 3-26 

Description 1-1 

Detector PROM correction: 

External frequency 3-18 

Detector PROM correction: User supplied frequency 

3-17 

Detector return loss test 5-7 

Detector Specifications D-2 

Detectors D-1 

Disassembly D-8 

Electrical Description D-4 

Maintenance D-7 

Preamplifier PC assembly D-4 

PROM PC assembly D-6 

Reassembly D-9 

Replacement of detector element D-8 

Specifications D-2 

Troubleshooting D-7 

Diagrams 8-1 

Digital delay PC assembly (A5) 4-12 


Clock 4-16 

Clock gate 4-16 

Counter 4-16 

CPU interface 4-14 

Delay board reset latch 4-17 

Internal trig comparators 4-15 

Interrupt latch 4-18 

Pulse shaper 4-18 

Ramp control logic 4-18 

Ramp generator 4-17 

Sample comparator 4-17 

Trig pulse stretcher 4-16 

Trig select 4-15 

Trig threshold 4-15 

Voltage hold 4-17 

Zero to 25.5 ns delay 4-18 

Digital Plotting of Graphic Data 2-30 

Plotters supported 2-30 

Procedure for making plots 2-30 

Display Formats C-1 

Display setups 2-46 

Dual Channel Measurements 2-32 

CW, CW measurements 2-32 

Peak, CW measurements 2-34 

Peak, peak measurements (method 1) 2-32 


Power ratio measurements 2-35 

Dual Channel Operation A-6 

CW mode commands A-6 

Other dual channel commands A-6 

Peak mode commands A-6 

Index-2 Manual No. 20790, Rev C, November 1998 


Index 

E 

Environmental requirements 1-2 

Equipment Required 5-2 

Error conditions 3-37 


External frequency and output frequency to controller 

command 3-19 

External memory 4-10 

External triggering 2-12 

F 

Frequency correction, cal factor and dB offset 2-16 

Frequency Display Disable/Enable 2-45 

Front Panel 


Front panel interface PC assembly (A8) 4-24 


Fuse 

Voltage selector and fuse holder (PCB) 2-3 

G 

General specifications 1-6 

Get power-on setup 2-45 

GPIB Command Descriptions 3-14 

1018B commands 3-38, 3-52 

Commands for retrieving data from the PPM 3-23 

Commands to output graphic data to a controller 3-33 

Common mode functions 3-15 

GPIB Command Summary 3-44 

Graph mode GPIB operation 3-24 

Marker timing measurements 3-26 

Measurement data correction 3-17 

Mode selection and control 3-21 

Plotting commands 3-34 

Programming notes 3-35 


GPIB/CAL control PC board (A3) 4-4 


Graph Mode 2-13 

Selecting the Graph mode 2-13 

Graph Mode Commands A-4 

Change between cursor, marker, 

and pulse sub-modes A-5 

Cursor sub-mode commands A-5 

Marker sub-mode commands A-5 

Pulse sub-mode commands A-5 

Graph mode GPIB operation 3-24 

Automatic functions of the Graph mode 3-24 

Automatic window delay selection 

related commands 2-24, 3-26 

Graph sub-mode selection commands 3-24 

Reading and defining pulse parameters 3-25 

Graph sub-mode selection commands 3-24 

H 

Hide and Unhide frequency information commands 

3-15 

High Power Measurement Procedures 2-37 

High Power Measurements 2-37 

High Power Measurement Procedures 2-37 

High power relative measurements 2-39 

max/min power 2-37 

Single pulse measurement using external trigger 2-41 

Single pulse measurement using internal trigger 2-40 

Single pulse measurements 2-40 

High power relative measurements 2-39 

I 

Initialization 5-12 

Initializing setups 2-46 

Initiating the 1018B emulation mode 2-47 

Installation 2-1 

Instrument plus power detector linearity test 5-3 

Internal trig comparators 4-15 

Internal triggering 2-12 

Interrupt latch 4-18 

Interrupt priority decoder 4-10 

Introduction 1-1 

Items furnished 1-2 

Items required 1-2 

L 

Linear power data format 3-13 


Log (dBm) data format 3-12 

M 

Maintenance 6-1 

Cleaning 1-2 

Diagrams 8-1 


Parts Lists 7-1 

Periodic 6-1 

Power-On failure 6-3 

Required test equipment 6-2 



Index-3


Troubleshooting 6-3 

Manual marker placement/timing measurement 

commands 3-29 

Marker sub-mode commands A-5 

Marker sub-mode functions 2-28 

Marker timing measurements 3-26 

Automatic timing measurement commands 3-28 

Manual marker placement/timing 

measurement commands 3-29 

Reference power related commands 3-27 

Window and cursor control commands 3-31 

Measurement data correction 3-17 

Detector PROM correction: External frequency 3-18 

Detector PROM correction: User 

supplied frequency 3-17 

External frequency and output frequency to 

controller command 3-19 

Offsetting measured data: dB offset commands 3-20 

User-defined detector calibration 

factor commands 3-20 

Measurement Procedures 2-16 



Cursor sub-mode functions 2-24 

CW power measurement 2-18 


Frequency correction, cal factor and dB offset 2-16 

Marker sub-mode functions 2-28 

Peak power measurement 2-19 

Peak power measurements (Graph mode) 2-23 

PROM frequency correction 2-16 

Pulse parameters sub-mode functions 2-26 

Pulse, cursor, and marker readouts 2-23 

User-supplied cal factor 2-17 

Memory features 2-45 

Display setups 2-46 

Get power-on setup 2-45 

Initializing setups 2-46 

Recall setup 2-45 

Store setup 2-45 

MEMory Key Displays B-4 

Menu and Memory Keys B-1 

MENU Key Displays B-1 

1018B emulation mode functions B-3 

Normal 8500A functions B-1 

Mode Selection 2-11 

CW mode 2-11 


Peak mode 2-11 

Mode selection and control 3-21 

N 

Peak power commands 3-21 

Related peak power commands 3-22 

Select Log or Linear power measurement format 

commands 3-21 

Select measurement mode commands 3-21 

Non-Volatile Memory 2-45 



Normal PPM operation 3-43 

O 

Offset 2-17 

Offsetting measured data: dB offset commands 3-20 

Operation 2-1, 2-10 

1018B emulation mode functions B-3 

1018B Peak Power Meter Emulation 2-47 

CW mode 2-11 


Display Formats C-1 

Dual Channel Measurements 2-32 

Frequency Display Disable/Enable 2-45 

General 2-1 


High Power Measurements 2-37 




MEMory Key Displays B-3 

Menu and Memory Keys B-1 

MENU Key Displays B-1 

Mode Selection 2-11 

Non-Volatile Memory 2-45 



Power-on self-test 2-10 

RF Detectors D-1 

Self-Calibration and Auto-Zeroing 2-14 

Self-Testing the 8500A 2-44 

Special Capabilities of the PPM 2-40 

Summary of Commands A-1 

Swept Peak Power Measurements 2-42 


Voltage selector and fuse holder (VDE) 2-4 

Warm Up time and temperature 2-10 

Options E-1 



Index 

Output data modes 3-38 

Output format 3-38 

Output modes 3-4 

Plot output mode 3-8 

Stand alone plot output mode 3-10 

Status byte 3-10 

Temperature difference output mode 3-10 

Update data continuously output mode 3-7 

Update trigger reset output mode 3-5 

Output status byte information command 3-16 


P 



External triggering 2-12 

Internal triggering 2-12 

Peak Mode Commands A-3 

Peak power commands 3-21 

Peak power measurement 2-19 



Peak power measurements (Graph mode) 2-23 

Peak, CW measurements 2-34 



Periodic Maintenance 6-1 


Plot output mode 3-8 

Plotter output/IEEE-488 interface 5-7 

Plotters supported 2-30 

Plotting commands 3-34 

Power limits 3-16 

Power linearity test setup 5-4 

Power measurement data output format 3-12 

Linear power data format 3-13 

Log (dBm) data format 3-12 

Power ratio measurements 2-35 

Ratio’ing Peak to CW signals 2-36 

Ratio’ing two CW signals 2-35 

Ratio’ing two Peak signals 2-35 

Power supply PC assembly (A2) 4-3 


Power warning - max/min power limits 2-37 

Power-On condition 3-3 


Self-test failure indications and possible causes 6-4 

Power-on self-test 2-10 

PPM IEEE bus functions 3-2 

PPM stand alone plot operation 3-43 

Procedure for making plots 2-30 

Programming notes 3-35 

PROM frequency correction 2-16 


User-supplied frequency 2-16 

Pulse parameters sub-mode functions 2-26 

Pulse rise time, width, and fall time 2-26 

Pulse rise time, width, and fall time 2-26 

Pulse shaper 4-18 

Pulse sub-mode commands A-5 

Pulse, cursor, and marker readouts 2-23 

R 

Ramp control logic 4-18 

Ramp generator 4-17 

range conditions 


Ratioing Peak to CW signals 2-36 

Ratioing two CW signals 2-35 

Ratioing two Peak signals 2-35 

Reading and defining pulse parameters 3-25 

Real time clock 4-10 

Rear Panel Description 2-5 

Recall setup 2-45 

Receiving inspection 1-2 

Reference delay 2-40 

Reference delay, correction of carrier frequency, and 

offset vs 1018B direct mode 3-39 

Reference Power 2-25 

Reference power related commands 3-27 

Related peak power commands 3-22 

Remote and local lockout functions 3-4 

Remote Operating Modes 3-2 

Command string format 3-12 


Output modes 3-4 

Power measurement data output format 3-12 

Power-On condition 3-3 

PPM IEEE bus functions 3-2 

Remote and local lockout functions 3-4 

Remote Operation 3-1 

1018B Emulation 3-38 

1018B Emulation Commands 3-38, 3-52 

Data Formats 3-52 

GPIB Command Descriptions 3-14 


Remote Operating Modes 3-2 

Service Requests 3-36 



Index-5


Summary of Bus Functions 3-41 

Remote Operation •% 3-41 

Remote state 3-39 


Reset timer 4-10 

Returning an Instrument 1-3 

S 

Safety 


Sample comparator 4-17 

Select Log or Linear power measurement format 

commands 3-21 

Select measurement mode commands 3-21 

Selecting the Graph mode 2-13 

Self-Calibration and Auto-Zeroing 2-14 

Auto-Zero function 2-15 

Self-Calibration failures 2-15 


Self-Calibration failures 2-15 



Self-Testing the 8500A 2-44 

Serial poll 3-39 


Calibration and Testing 5-1 

Cleaning 1-2 

Cooling 1-2 



Environmental requirements 1-2 

Front Panel Operation 2-1 


Introduction 1-1 

Items furnished 1-2 

Items required 1-2 

Maintenance 6-1 


Operation 2-1, 2-10 

Options E-1 


Receiving inspection 1-2 

Remote Operation 3-1 

Returning an Instrument 1-3 

RF Detectors D-1 


System Description 4-1 

System Specifications 1-4 

Theory of Operation 4-1 


Service Requests 3-36 

Error conditions 3-37 

Single pulse measurement using external trigger 2-41 

Single pulse measurement using internal trigger 2-40 

Single pulse measurements 2-40 

Special Capabilities of the PPM 2-40 

Reference delay 2-40 

SRQ related commands 3-16 

Stand alone plot output mode 3-10 

Start delay 2-24 

Status byte 3-10 

Status Code Decimal Values 3-41 

Store or recall setup commands 3-15 

Store setup 2-45 

Summary of Bus Functions 

Normal PPM operation 3-43 

PPM stand alone plot operation 3-43 


Commands Applicable to All Modes A-1 

CW Mode Commands A-3 

Dual Channel Operation A-6 

Graph Mode Commands A-4 

IEEE & 1018B emulation commands A-6 

Peak Mode Commands A-3 

Swept Peak Power Measurements 2-42 









System Specifications 1-4 

Auxiliary inputs/outputs 1-5 

Calibrator specifications 1-5 


General 1-6 

Remote operation 1-5 

T 

Temperature difference output mode 3-10 

Temperature difference since last calibration 

commands 3-15 

Test points 






Index 


A6/A7 Test points 4-23 


The microprocessor 4-9 

Theory of Operation 4-1 









Tools and test equipment also Series 8500A Peak 

Power Meters 1-2 

Trig pulse stretcher 4-16 

Trig select 4-15 

Trig threshold 4-15 

Trigger 2-25 


Equipment required 6-3 



Two detectors 3-39 

U 

Unbuffered memory 4-10 

Update data continuously output mode 3-7 

Update trigger reset output mode 3-5 

User-defined detector calibration factor 

commands 3-20 

User-supplied cal factor 2-17 

Offset 2-17 

User-supplied frequency 2-16 

V 

Voltage hold 4-17 

Voltage proportional to frequency test 5-7 

Voltage selector 




Volume adjust 5-20 

W 

Warm Up time and temperature 2-10 

Window and cursor control commands 3-31 

Z 

Zero to 25.5 ns delay 4-18 



Index-7

Manual - 8500A Series Peak Power Meter - Giga-tronics

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