Giga-tronics 2508A User manual

2500A Serie
s
2500A Series Microwave Synthesizer Operations Manual
34172, Revision C, March 2008

WARRANTY
Giga-tronics 2500A Series instruments are
warranted against defective materials and
workmanship for four years 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 2500A Series has model numbers for each instrument with a specific frequency range as described in Chapter 1.
All models are referred to in this manual by the general term 2500A, except where it is necessary to make a
distinction between the models. In these cases, the specific model number(s) will be used.
Giga-tronics, Incorporated
4650 Norris Canyon Road
San Ramon, California 94583
TEL: [phone]
925.328.4650
FAX: [phone]
www.gigatronics.com
All technical data and specifications in this publication are subject to change without prior notice and do not
represent a commitment on the part of Giga-tronics, Incorporated.
© 2004 Giga-tronics Incorporated. All rights reserved. Printed in the USA.

89/336/EEC and 73/23/EEC EMC Directive and Low Voltage Directive
EN61010-1 (1993) Electrical Safety
EN61326-1 (1997) EMC - Emissions & Immunity
Manufacturer’s Name: Manufacturer’s Address:
Giga-tronics, Incorporated 4650 Norris Canyon Road
San Ramon, California 94583
U.S.A.
Type of Equipment: Model Series Number:
Standard(s) to which Conformity is Declared:
Microwave Synthesizer 2500A Series
Model Numbers In Series:
2508A, 2520A, 2526A, 2540A
Declaration of Conformity
Application of Council Directive(s)
Declaration of Conformity on file. Contact Giga-tronics, Inc.
4650 Norris Canyon Rd.
San Ramon, CA 94583
Ph: 1-925-328-4650
Fx: 1-925-328-4700
2508AS, 2520AS, 2526AS, 2540AS

2500A Series Operation Manual, 34172 Revision C, March 2008
Preface
This publication provides an overview and describes local (front panel) operation, remote operation,
specifications, and performance verification of the Giga-tronics 2500A family of Microwave Synthesiz-
ers. This Preface contains chapter descriptions, a record of changes made to the publication since its pro-
duction, and a description of the special configurations. Changes that occur after production of this
publication, and Special Configuration data will be inserted as loose bound pages in the publication
binder. Please insert and/or replace the indicated pages as detailed in the Technical Publication Instruc-
tions included with new and/or replacement pages.
Chapters:
1- Introduction
This chapter contains an overview of the 2500A, basic system information, and input and output descrip-
tions.
2 - Front Panel Operation
This chapter contains information about front panel operation of the instrument. Controls, features, and
menus are described, operating tasks are explained, and factory default settings are listed.
3- Remote Operation
This chapter contains information about remote operation of the instrument over the General Purpose
Interface Bus (GPIB) or RS-232.
4- Specifications & Performance Verification
This chapter contains 2500A specifications and step-by-step procedures to verify 2500A Series Micro-
wave Synthesizer performance.
Appendices:
A- Accessories and Options
This appendix describes the accessories and options that are available for the 2500A Series Microwave
Synthesizers. Each accessory and option is described under its respective heading.
B - Error Messages
This appendix provides a description of the various error messages and other user messages that might be
encountered during instrument operation.
Index
A subject listing of contents.
About The Publication

6 2500A Series Operation Manual, 34172 Revision C, March 2008
The following safety conventions are used in this publication. Additional conventions not included here are
defined at the time of usage.
Warning
WARNING
The WARNING statement is encased in gray 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 with single 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 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.
Conventions

2500A Series Operation Manual, 34172 Revision C, March 2008
Giga-tronics: Serial, Code, Models, Option or Configuration Label
Examine the code, model number, serial number, and option/configuration label affixed to the rear panel of the
2500A Microwave Synthesizer.
Code Number
Each instrument has a two-digit code, referred to as the Manufacturing Configuration Code.
Model Number
Each instrument has a four-digit model number in the form 25XX, and one or two character suffix which desig-
nates the series:
- 25XXB - Benchtop model
- 25XXS - ATE model
The frequency range of the instrument is designated by the model number:
- 2508A - 0.1 MHz to 8 GHz
- 2520A - 0.1 MHz to 20 GHz
- 2526A - 0.1 MHz to 26.5 GHz
- 2540A - 0.1 MHz to 40 GHz
Serial Number
Each instrument has a seven-digit serial number, shown on the label of the rear panel.
Option Number(s)
When options are installed, one or more 2 digit numbers are listed on the “Opt.” line and correspond to
options installed in the instrument. Option numbers are explained in Appendix A.
Special Configurations
When the accompanying product has been configured for user-specific application(s), supplemental pages will
be inserted at the front of the publication binder. Remove the indicated page(s) and replace it (them) with the
furnished Special Configuration supplemental page(s).
If the “Opt.” line contains a three digit number (for example, 641), there is combination of options and/or spe-
cial modifications installed in the instrument. Information relating to these special configurations is contained
in supplemental pages included with the manual.
Configuration Data

8 2500A Series Operation Manual, 34172 Revision C, March 2008
This table is provided for your convenience to maintain a permanent record of publication change data.
Replacement pages will be issued as a TPCI (Technical Publication Change Instruction), and will be
inserted at the front of the binder. Remove the corresponding old pages, insert the new pages, and
record the changes here.
TCPI Number TPCI Issue Date Date Entered Comments
Record of Publication
Changes

2500A Series Operation Manual, 34172 Revision C, March 2008
9
Table of Contents
CHAPTER 1: 2500A INTRODUCTION
1.1 Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.1.1 2500A Frequency Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.1.2 2500A Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.1.3 Items Furnished . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.1.4 Items Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.2 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.2.1 Receiving Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.2.2 Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.2.3 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.2.4 Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.2.5 Line Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.2.5.1 Line Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.2.6 Calibration Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.2.7 Reshipment Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.3 Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.3.1 Front Panel Connector (RF Output). . . . . . . . . . . . . . . . . . . . . . . . 19
1.3.2 Rear Panel Interface and I/O Connectors. . . . . . . . . . . . . . . . . . . . 19
CHAPTER 2: FRONT PANEL OPERATION
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2 Front Panel At a Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.1 Front Panel Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3 2500A Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.3.1 Menu System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.1.1 Menu Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.2 CW Menu Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.3.2.1 Cable Cal Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.3.3 RAMP Menu Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.3.3.1 Ramp Freq 1 Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.3.3.2 Ramp Freq 2 Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.3.3.3 Ramp Power Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.3.3.4 Step Sweep Freq Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.3.4 SYSTEM Menu Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.3.4.1 System 1 Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.3.4.2 System 2 Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.3.4.3 System Menu 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.3.4.4 System Menu 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

10 2500A Series Operation Manual, 34172 Revision C, March 2008
2.3.5 AM Menu Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.3.5.1 External AM Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.3.5.2 AM - Internal Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.3.5.3 AM - Internal Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.3.6 FM Menu Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.3.6.1 FM - External Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.3.6.2 FM - Internal Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.3.6.3 DC FM Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
2.3.7 PM Menu Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.3.7.1 PM - External Source Menu . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.3.7.2 PM Internal-Continuous Menu . . . . . . . . . . . . . . . . . . . . . . . 47
2.3.7.3 PM Internal-Gated Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.3.7.4 PM Internal-Triggered Menu . . . . . . . . . . . . . . . . . . . . . . . . 50
2.3.8 Language Menu Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
2.3.8.1 Language Menu 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
2.3.8.2 Language Menu 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2.3.8.3 Language Menu 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
2.4 Front Panel Operating Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2.4.1 Power-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2.4.1.1 Normal Power-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2.4.1.2 Errors During Power-Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.4.2 Basic Operating Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.4.2.1 Resetting the System/Sanitization Procedure . . . . . . . . . . . . 57
2.4.2.2 Entering and Modifying Parameters . . . . . . . . . . . . . . . . . . . 57
2.4.3 Signal Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
2.4.3.1 Generating a CW Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
2.4.3.2 Generating an External ALC Leveled Signal . . . . . . . . . . . . 60
2.4.3.3 Using the Ref Tune Feature . . . . . . . . . . . . . . . . . . . . . . . . . 62
2.4.3.4 Cable Correction Function . . . . . . . . . . . . . . . . . . . . . . . . . . 63
2.4.3.4 Required Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
2.4.3.5 Configuring the 8650A Universal Power Meter . . . . . . . . . . 64
2.4.3.6 Configuring the Cable Correction Setup. . . . . . . . . . . . . . . . 64
2.4.3.7 Generating a Frequency Swept Signal . . . . . . . . . . . . . . . . . 65
2.4.3.8 Generating a Power Swept Signal. . . . . . . . . . . . . . . . . . . . . 65
2.4.3.9 Generating an Externally Pulse Modulated Signal . . . . . . . . 66
2.4.4 Remote Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
2.4.4.1 Setting the GPIB Address . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
2.4.4.2 Selecting the Remote Language . . . . . . . . . . . . . . . . . . . . . . 68
CHAPTER 3: REMOTE OPERATION
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

2500A Series Operation Manual, 34172 Revision C, March 2008
11
3.1.1 What is Automation Xpress? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
3.1.2 Computer Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
3.2 SCPI Command Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
3.2.1 SCPI Command Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
3.2.2 SCPI Command Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.2.2.1 Output Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.2.2.2 Source Subsystem - CW Mode . . . . . . . . . . . . . . . . . . . . . . . 72
3.2.2.3 Source Subsystem - Correction . . . . . . . . . . . . . . . . . . . . . . . 73
3.2.2.4 Source Subsystem - List Mode . . . . . . . . . . . . . . . . . . . . . . . 73
3.2.2.5 Status Subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
3.2.2.6 System Subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
3.2.2.7 Trigger Subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
3.2.2.8 Source Subsystem - Ramp Sweep. . . . . . . . . . . . . . . . . . . . . 77
3.2.2.9 Source Subsystem- Modulation . . . . . . . . . . . . . . . . . . . . . . 78
3.3 IEEE 488.2 Common Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
3.4 2500A Specific Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.5 Status Register System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
3.5.1 Status Byte (STB) and Service Request Enable (SRE)
Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
3.5.2 Standard Event Status (ESR) and Standard Event Status
Enable (ESE) Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
3.5.3 Questionable Status Condition and Enable Registers . . . . . . . . . . 85
3.5.4 List Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
3.5.4.1 Example: List Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
CHAPTER 4: SPECIFICATIONS & PERFORMANCE VERIFICATION
4.1 Models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
4.2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
4.2.1 Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
4.2.1.1 Frequency Bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
4.2.2 Output Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
4.2.3 Spectral Purity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
4.2.4 List Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
4.2.5 Amplitude Modulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.2.6 Frequency Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.2.7 Pulse Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.2.8 External ALC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
4.2.9 Internal Modulation Generator. . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4.2.10 General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
4.3 Performance Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
4.3.1 Recommended Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

12 2500A Series Operation Manual, 34172 Revision C, March 2008
4.3.2 Performance Tests: All 2500A Series . . . . . . . . . . . . . . . . . . . . . . 99
4.3.2.1 Frequency Range, Resolution & Accuracy. . . . . . . . . . . . . . 99
4.3.2.2 Spectral Purity Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
4.3.2.3 RF Output Power Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
4.3.3 Performance Tests: 2500A Series . . . . . . . . . . . . . . . . . . . . . . . . . 104
4.3.3.1 Amplitude Modulation Tests . . . . . . . . . . . . . . . . . . . . . . . . 104
4.3.3.2 Frequency Modulation Tests. . . . . . . . . . . . . . . . . . . . . . . . . 107
4.3.3.3 Pulse Modulation Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
4.3.3.4 Internal Modulation Generator Tests . . . . . . . . . . . . . . . . . . 114
4.3.4 2500A Series Test Datasheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
APPENDIX A: ACCESSORIES & OPTIONS
A.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
A.2 List of Accessories and Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
APPENDIX B: ERROR MESSAGES
B.1 Start-Up Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
B.2 NVRAM Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
B.2.1 NVRAM Reset Due to a Firmware Upgrade . . . . . . . . . . . . . . . . 127
B.2.2 NVRAM Reset Due to a Battery Failure . . . . . . . . . . . . . . . . . . . 127
B.2.3 NVRAM Reset Due to a Checksum Failure . . . . . . . . . . . . . . . . . 127
B.3 Remote Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

2500A Series Operation Manual, 34172 Revision C, March 2008
2500A Introduction
1.1 Overview
The Giga-tronics 2500A Microwave Synthesizers deliver industry-leading performance combining out-
standing low phase noise performance, high output power, and fast switching simultaneously. These fea-
tures of the 2500A Synthesizer family make it an excellent test solution for a wide range of CW,
modulation, swept frequency, and fast frequency switching RF and Microwave applications in both R&D
and manufacturing environments. All 2500A Synthesizers comply with MIL-PRF-28800F, Class 3.
The 2500A Synthesizer family is available in two series, with four unique models within each series.
Table 1-1 lists the model numbers, and the frequency ranges covered by each model.
2500A Series. The 2500A Series includes frequency ranges from 100 kHz to 8 GHz, 20 GHz,
26.5 GHz, and 40 GHz. In addition, external ALC, ramp frequency and power sweep, high stability time-
base, 100 MHz reference output, DC-FM, AM, FM, and Pulse capability, and Automation Xpress Inter-
face software and rack ears are all standard features.
1.1.1 2500A Frequency Ranges
Table 1-1 shows the various models of the 2500A Series Microwave Synthesizers, and their respective
RF output frequency ranges:
Table 1-1: 2500A Frequency Ranges
Models Frequency Range
2508A/2508AS 100 kHz to 8 GHz
2520A/2508AS 100 kHz to 20.199 GHz
2526A/2508AS 100 kHz to 26.5 GHz
2540A/2508AS 100 kHz to 40 GHz
1

Chapter 1: 2500A Introduction
14 2500A Series Operation Manual, 34172 Revision C, March 2008
1.1.2 2500A Options
The following briefly describes the options that are available within the various series of the 2500A.
Appendix A further describes the options:
• Option 17A- Delete Modulation
• Option 17B - Delete Modulation Function Generator
• Option 18- Delete 10 MHz - 2 GHz Frequency Extension
• Option 23 - Type N Connector (2520 Models only)
• Option 26- Delete 90 dB Step Attenuator
• Option 31- Reduced Frequency Switching and Pulse Width Performance
• Option 44- Delete Display Front panel
• Option 46- Rack Slide Kit
• Option 55- Command Sets
• 55A - HP 8370
• 55B - HP 8340
• 55C - HP 8673
• 55D - HP 8662
• 55E - Systron-Donner 1720
• 55F - Wavetek 90X
• 55G - HP 8350
• 55H - HP 8360
1.1.3 Items Furnished
Accessories and Options are detailed in Appendix A of this publication. In addition to the options and/or
accessories specifically ordered, the following items are furnished with the instrument:
• Operation Manual
• USB 1.1/RS-232 Cable Adapter
• Power Cord, 6 ft.
• Giga-tronics Automation Xpress Software Package
1.1.4 Items Required
No special items are required to operate the 2500A Series during local (front panel) operation. Remote
operation requires some of the following items depending on the interface used:
• IEEE 488 Interface Cable
• PC with GPIB, RS-232, or USB

General Information
2500A Series Operation Manual, 34172 Revision C, March 2008
• Standard 9 Pin Type D Serial Cable
Test equipment required for performance verification is described in Chapter 4.
1.2 General Information
All instruments are shipped in operational condition. No special installation procedures are required.
Each 2500A Series model must pass rigorous inspections and tests prior to shipment. Following installa-
tion, a performance verification should be performed to ensure that operation has not been impaired dur-
ing shipment. The following below apply to all models:
• Unless otherwise stated, warm-up time of 30 minutes for normal operation
• Performance Verification procedures are outlined in Chapter 4
1.2.1 Receiving Inspection
Use care when removing the instrument from the carton and immediately inspect for physical damage,
such as bent or broken connectors on the front and rear panels, dents or scratches on the panels, broken
handles, etc. Check the shipping carton for evidence of physical damage and immediately report any
damage to the carrier.
1.2.2 Cooling
A cooling fan is installed in all 2500A Series instruments. The cooling air intake is located on the rear
panel. Care must be taken to avoid obstructing the flow of air into the instrument.
1.2.3 Cleaning
The air intake screen should be cleaned whenever a significant amount of dust has accumulated on it.
Whenever the instrument covers are removed, the interior should be blown out with a dry air at a low
velocity.
1.2.4 Power
All 2500A models contain primary and standby power with internal switching. The instrument automati-
cally senses input line voltage in the range of 90 to 253 Vac, 47 to 440 Hz. There are no manual voltage
adjustments or selection controls (the voltage select wheel within the power module is not used in the
2500A). All 2500A Series have a 3-Wire power cord with a 3-terminal polarized plug for connection to

Chapter 1: 2500A Introduction
16 2500A Series Operation Manual, 34172 Revision C, March 2008
the power source and safety ground. The power cord must not exceed 3 meters (9 feet) to meet safety
requirements.

General Information
2500A Series Operation Manual, 34172 Revision C, March 2008
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 poses a shock haz-
ard.
DO NOT position the equipment so that it is difficult to remove the AC line cord.
1.2.5 Line Fuse
All 2500A Series models have a line fuse holder on the rear panel. The power line fuse is 2A, Slow-
Blow, 250V, Type T. See Figure 1-1 below for the location of the line fuse.
Figure 1-1: Fuse Holder
1.2.5.1 Line Fuse Replacement
Open the housing cover. 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 1-1, above.
WARNING
WARNING
CAUTION
110
120
COVER
FUSE AND
FUSE HOLDER
AC POWER
INPUT
Not Used

Chapter 1: 2500A Introduction
18 2500A Series Operation Manual, 34172 Revision C, March 2008
NOTE: The voltage select wheel shown in Figure 1-1, above, can be set at any position. Its position
has no effect on the 2500A line voltage, as the 2500A line voltage is auto-sensing and auto-
setting.
1.2.6 Calibration Cycle
Giga-tronics recommends a calibration cycle of two years for the 2500A.
1.2.7 Reshipment Preparation
If it is necessary to return the instrument to the factory, protect it during reshipment using the best pack-
aging materials available. If possible, reuse the original shipping container. If the original shipping con-
tainer is not available, use a strong carton (350lbs./ sq.in. bursting strength) or a wooden box. Wrap the
instrument in heavy paper or plastic before placing it into the shipping container. Completely fill the
areas on all sides of the instrument with packaging material. Take extra precaution to protect the front
and rear panels. Seal the package with strong tape or metal bands. Mark the outside of the package as fol-
lows:
If corresponding with the factory or local Giga-tronics sales office regarding reshipment, please provide
the model and serial number. If the instrument is being returned for repair, be sure to enclose all relevant
information regarding the problem that has been found.
NOTE: If returning an instrument to Giga-tronics for service, first contact Customer Service so that a
return authorization number (RMA) can be assigned. Contact Giga-tronics via email
([email protected]) or by phone [phone]). The 800 number is only valid within
in the United States. Contact can also occur via our domestic line at (925.328.4640) or Fax at
(925.328.4702).
1.3 Inputs and Outputs
The input and output connectors are shown in figures 1-2 and 1-3. Table 1-3 contains the front and rear
panel I/O connector functional descriptions for all 2500A Series models.
FRAGILE - DELICATE INSTRUMENT

Inputs and Outputs
2500A Series Operation Manual, 34172 Revision C, March 2008
1.3.1 Front Panel Connector (RF Output)
This is the instrument’s RF output. It is located on the front panel of 2500B Series Synthesizer models,
and on the rear panel of versions of 2500S Series models.
The type of RF connector that is supplied depends on the frequency range of the instrument. Figure 1-2
shows the general location of the front panel RF output connector on 2500B Series models, and
Table 1-2 indicates by model the type of RF connector that is supplied.
Figure 1-2: Series 2500B Front Panel Output
1.3.2 Rear Panel Interface and I/O Connectors
This section defines the functions of the 2500A Series rear panel connectors (see Figure 1-3).
Table 1-2: RF Connector Types
Models RF Connector Type
2508A/2508AS N (f)
2520A/2520AS
2526A/2526AS
SMA (f)
2540A/2540AS K (f)
ALC IN
RF OUT
RF
ON

Chapter 1: 2500A Introduction
20 2500A Series Operation Manual, 34172 Revision C, March 2008
Figure 1-3: 2500A Rear Panel
All rear panel I/O connectors explained in this section are type BNC unless otherwise stated. Some con-
nectors may not be supported because of installed options. For example, Modulation and Modulation
Generator connectors are not active with Option 17A or 17B. Table 1-3 describes the 2500A rear panel
I/O connectors.
Table 1-3: 2500A Rear Panel I/O Connector Descriptions
Connector Label Description
EXT ALC In external leveling, the output of the 2500B is detected by either a positive or negative
crystal detector or power meter with an analog output. The signals from these devices
are connected to the ALC circuitry of the 2500B which is used to compensate for
standing wave effects or cable and component losses at the input of the device under
test.
See Section 4.2.8 for External ALC specifications
RF OUT The RF signal output for the instrument. See Table 1-2 for RF connector types.
It is located on the front panel for all 2500B Series instruments and rear panel for all
2500S Series instruments.
FM OUT1The internal modulation generator output;
2 Vp-p into 10k Ω.
PULSE OUT1A +4V video representation of the pulsed RF output signal.
AM OUT1The internal modulation generator output;
2 Vp-p into 10k Ω.
PM SYNC OUT1A synchronization output pulse of >75 ns width, TTL level that can be delayed relative
to the leading edge of the video signal at the PULSE OUT connector.
FM IN2A 50 Ωinput for an external FM signal. The input signal can be any waveform
compatible within bandwidth considerations. A 1 Vp input produces maximum
deviation.
An externally supplied DC signal can be applied to modulate the frequency of the CW
output using this connector.
See Section 4.2.6 for DC FM specifications
AM IN2A 600 Ωinput for an external AM signal. The input signal can be any waveform
compatible within bandwidth considerations. A 1 Vp-p input produces 50% AM depth.
PULSE IN/PM TRIG IN2A Pulse Modulation Input for external pulse gating, pulse triggering or external Pulse In.
The input parameters are +5 volt, 50 Ω
LOCK/LEVEL +5 volt indicator, active high when the 2500A is phase locked and output leveled. The
Lock and Level indicator is valid for CW mode only.
REF TUNE A 0 to +10 volts, high impedance input for tuning the internal reference for adjusting the
output frequency approximately +5 ppm. Do not exceed +15 volts or apply a negative
voltage greater than -1 volt.
SYNC OUT In List mode, the unit can be set to generate a pulse at this output when a specified list
point is reached. The output can be delayed from the start of the list point up to a
maximum of 10 msec. The pulse width of the SYNC OUT signal is determined by the
following parameters: pulse width = Step Time - Sync Delay - 10 usec
In Ramp operation, the pulse occurs at the start of each ramp sweep.
In either case, the output pulse is +5 volt.