HP 8640b schematic
TM 11-6625-2780-14&P
TECHNICAL MANUAL
OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT
AND GENERAL SUPPORT MAINTENANCE MANUAL
INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS
FOR
SIGNAL
GENERATORS SG-1 112(V)1/U
(NSN 6625-00-566-3067)
AND SG-1l12(V)2/U
(NSN 6625-00-500-6525)
(HEWLETT-PACKARD MODEL 8640B,
OPTIONS 001 AND 004)
HEADQUARTERS, DEPARTMENT OF THE ARMY
31 DECEMBER 1980
By Order of the Secretary of the Army:
Official:
J. C. PENNINGTON
Major General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with distribution list.
E. C. MEYER
General, United States
Chief of Staff
Army
This manual contains copyright material reproduced by permission of the Hewlett-Packard Company.
TM 11-6625-2780-14&P
T ECHNICAL M ANUAL
No. 11-6625-2780-14&P
DEPARTMENT OF THE ARMY
W
ASHINGTON
HEADQUARTERS
, DC
31 December 1980
OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT,
AND GENERAL SUPPORT MAINTENANCE MANUAL
INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS
FOR
SIGNAL GENERATORS SG-1112(V)1/U (NSN 6625-00-566-3067)
AND SG-1112(V)2/U (NSN 6625-00-500-6525)
(HEWLETT-PACKARD MODEL 8640B, OPTIONS 001 AND 004)
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistakes or if you know of a way to improve the
procedures, please let us know. Mail your letter, DA Form 2028 (Recommended Changes to Publications and
Blank Forms), or
munications and Electronics Materiel Readiness Command and Fort Monmouth, ATTN: DRSEL-ME-MQ,
Fort Monmouth,
In either case, a reply will be furnished direct to you.
DA
Form 2028-2 located in the back of this manual, direct to: Commander, US Army Com-
NJ 07703.
This manual is an authentication of the manufacturer’s commercial literature which, through usage, has been found to
rover the data required to opersaate and maintain this equipment. The manual was not prepared in accordance with military
specifications; therefore, the format has not been structured to consider categories of maintenance.
i
Model 8640B Option 004
Table of Contents
CONTENTS
Section
o
INTRODUCTION . . . . . . . . . . . . . . . . . . . 0-1
I
GENERAL INFORMATION . . . . . . . 1-1
Introduction . . . . . . . . . ...1-1
1-1.
1-6.
Specifications . . . . . . . . . . . . 1-1
1-8.
Instruments Covered by Manual . . . . . . 1-1
1-13.
General Description . . . . . . . . . . 1-2
Performance Characteristics . . . . . . . 1-2
1-19.
1-20.
1-26.
1-31.
1-37.
1-42.
1-45.
1-48.
1-51.
1-57.
1-61.
1-65.
1-69.
1-76.
1-82.
II
2-1.
2-3.
2-5.
2-6.
2-8.
2-11.
2-13.
2-15.
2-18.
2-20.
2-22.
2-23.
2-25.
III
3-1.
3-3.
3-5.
3-7.
3-9.
IV
4-1.
4-4.
4-6.
4-8.
4-12.
Spectral Purity . . . . . . . . . . 1-2
Frequency Counter . . . . . . . . . 1-3
Phase-Lock Mode . . . . . . . . . 1-3
Amplitude Modulation . . . . . . . . 1-4
Pulse Modulation . . . . . . . . . . 1-4
Frequency Modulation . . . . . . . . 1-4
Standard and Optional Audio Oscillators . . 1-5
Multi-Function Meter and Annunciators . . 1-5
Output Level . . .
Options . . . . . .
Accessories Supplied .
Equipment Available .
Service and User Aids .
Test Equipment Required
INSTALLATION . . .
Introduction . . . .
Initial Inspection . . .
Preparation for Use . .
Power Requirements
Line Voltage Selection
Power Cable . . .
Mating Connectors .
Operating Environment
Bench Operation . . .
Rack Mounting . . .
Storage and Shipment . .
Environment . . . .
Packaging . . . . .
OPERATION . . . . .
Introduction . . . . .
Panel Features . . . .
Operator’s Checks . . .
Operating Instructions . .
Operator’s Maintenance .
PERFORMANCE TESTS
Introduction . . . . .
Equipment Required . .
Test Record . . . . .
Test Procedures . . . .
Basic Functional Checks .
. .
. . . . . . . .
. . . . . . . .
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Page
1-6
1-6
1-6
1-6
1-7
1-7
2-1
2-1
2-1
2-1
2-1
2-2
2-2
2-3
2-3
2-3
2-3
2-3
2-3
2-3
3-1
3-1
3-1
3-1
3-1
3-1
4-1
4-1
4-1
4-1
4-1
4-5
Section
IV PERFORMANCE TESTS (cont’d)
4-13. Frequency Range Test . . . . . . .
4-14. Frequency Accuracy and Fine Tune Test .
4-15. Frequency Stability Vs Time and
Restabilization Time Test . . . .
4-16. Frequency Stability Vs Temperature Test.
4-17. Frequency Stability Vs Line Voltage Test .
4-18. Frequency Stability Vs Load, Level, and
Mode Test . . . . . . . . . .
4-19. Harmonics Test . . . . . . . . .
4-20. Sub-Harmonics and Non-Harmonic
Spurious Test . . . . . . . .
4-21. Single Sideband Phase Noise Test . . .
4-22. Single Sideband Broadband Noise Floor
Test . . . . . . . . . . . .
4-23. Residual AM Test . . . . . . . .
4-24. Residual FM Test . . . . . . . .
4-25. Output Level Accuracy Test (abbreviated).
4-26. Output Level Accuracy Test (complete) .
4-27. Output Level Flatness Test . . . . .
4-28.
Output Impedance Test (Signal-Frequency) . 4-47
Output Impedance Test (Broadband) . . . 4-49
4-29.
4-30.
Auxiliary Output Test . . . . . . . . 4-50
4-31.
Output Leakage Test . . . . . . . . 4-51
4-32.
Internal Modulation Oscillator Test . . . . 4-53
4-33.
Internal Modulation Oscillator
Distortion Test (Option 001) . . . . . 4-55
4-34.
AM 3 dB Bandwidth Test . . . . . . . 4-56
4-35.
AM Distortion Test . . . . . . . . . 4-58
4-36.
AM Sensitivity and Accuracy Test . . . . 4-59
Peak Incidental Phase Modulation Test . . 4-62
4-37.
4-38.
Demodulated Output Accuracy Test . . . 4-65
4-39.
AM Phase Shift Test . . . . . . . . . 4-69
4-40.
AM Flatness Test . . . . . . . . . . 4-71
4-41.
Pulse Modulation Test . . . . . . . . 4-73
Pulse On/Off Ratio Test . . . . . . . 4-77
4-42.
4-43.
FM 3 dB Bandwidth Test . . . . . . . 4-78
4-44.
FM Distortion Test . . . . . . . . . 4-79
4-45.
FM Sensitivity and Accuracy Test . . . . 4-81
4-46.
Incidental AM Test . . . . . . . . . 4-85
4-47.
Counter External Sensitivity Test . . . . 4-87
4-48.
Internal Reference Accuracy Test . . . . 4-88
4-49.
Internal Reference Drift Rate (Stability)
Test . . . . . . . . . . . . .4-89
Phase Lock Restabilization Time Test . . . 4-92
4-50.
V
ADJUSTMENTS . . .
Introduction . . . .
5-1.
5-3.
Safety Considerations .
5-9. Test Equipment Required
5-11.
Posidriv Screwdrivers
.
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
Page
4-13
4-14
4-16
4-18
4-19
4-20
4-21
4-23
4-25
4-27
4-30
4-31
4-34
4-39
4-45
5-1
5-1
5-1
5-1
5-1
ii
Table of Contents
Model 8640B Option 004
CONTENTS (cont'd)
Section
V
ADJUSTMENTS (cont'd)
5-13.
5-15.
5-19.
5-22.
5-25.
5-26.
Blade Tuning Tools . . . . . . .
Service Aids . . . . . . . . .
Factory Selected Components . . . .
Post-Repair Tests and Adjustments . . .
Power Supply Adjustments . . . . .
Fixed-Frequency Modulation Oscillator
Adjustment . . . . . . . . .
Variable Frequency Modulation Oscillator
5-27.
Adjustment (Option 001) . . . . .
Meter Adjustments . . . . . . . .
5-28.
RF Detector Offset Adjustment . . . .
5-29.
.
. .
. .
. .
. .
. .
. .
. .
. .
Page
5-1
5-1
5-2
5-3
5-8
5-8
5-9
5-12
5-13
5-30. Output Level Vernier and Meter Adjustment. . 5-14
5-31. Preliminary AM Adjustments . . . . . . 5-17
5-32. AM Accuracy Adjustment . . . . . . . . 5-19
5-33. Peak Deviation and Range Switch
Adjustment . . . . . . . . .
5-34.
Range Switch Adjustment . . . . . .
VT Pot (A3R1) Adjustment . . . . .
5-35.
VT Voltage Adjustment . . . . . .
5-36.
5-37.
RF Oscillator End Stop Adjustment . .
RF Oscillator Output Power Adjustment .
5-38.
5-39.
RF Filter Adjustment . . . . . . .
5-40.
preliminary FM Adjustments . . . . .
FM Linearity Adjustment . . . . . .
5-41.
5-42.
FM Linearity Adjustment (Alternate) . .
5-43.
FM Sensitivity Adjustment . . . . .
Internal Reference Frequency Adjustment
5-44.
VI
REPLACEABLE PARTS . . . . . . . .6-1
Introduction . . . . . . . . . ...6-1
6-1.
Exchange Assemblies . . . . . . . . . 6-1
6-3.
Abbreviations. . . . . . . . . . . .6-1
6-5.
Replaceable Parts List . . . . . . . . .6-1
6-7.
Ordering Information . . . . . . . . . 6-1
6-11.
Spare Parts Kit . . . . . . . . . .. 6-1
6-14.
6-16.
Illustrated Parts Breakdowns . . . . . . . 6-2
VII
MANUAL CHANGES . . . . . . . . .7-1
7-1.
Introduction . . . . . . . . . . ..7-1
7-3.
Manual Changes.. . . . . . . . ..7-1
7-6.
Manual Change Instructions . . . . . . . 7-4
7-7.
Instrument Improvement Modifications . . . 7-16
7-9.
Improved FM Bandwidth on 5 kHz Devia-
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
5-22
5-22
5-23
5-25
5-25
5-28
5-29
5-33
5-35
5-38
5-40
5-42
tion Range (Serial Number Prefixes
1323A and 1327A) . . . . . . . . .7-16
Section
7-11.
A10A2 RF Divider Assembly Improvement
(Serial Number Prefixes 1333A and Below).
7-13.
A18, A20, and A22 Power Supply Regulator Improvements (Serial Number Prefixes
1333A and Below) . . . . . . . .
7-15.
Al1 Variable Frequency Modulation
Oscillator Improvements (Serial Number
Prefixes 1339A and Below) . . . . .
7-18.
A12 Rectifier Assembly Input Crowbar
Failures (Serial Number Prefixes 1339A
and Below) . . . . . . . . . . .
7-20.
Reliability Improvements in AM and Pulse
Circuits (Serial Number Prefixes 1345A
and Below) . . . . . . . . . .
7-23.
All Variable Frequency Modulation
Oscillator (Option 001) Improvement
(Serial Number prefixes 1350A and
Below) . . . . . . . . . . .
7-26.
Improvement in Lock Acquisition Capability (Serial Number Prefixes 1350A
and Below). . . . . . . . . .
7-28.
+44.6V Regulator Improvement (Serial
Number Prefixes 1405A and Below) .
7-30.
Line Switch Modification (Serial Number
Prefixes 1406A and Below) . . . . .
7-33.
Reduction in Popcorn Noise on Power
Supplies (Serial Number Prefixes 1406A
and Below) . . . . . . . . . . .
7-35.
Recommended Fuse Replacement for
220/240V Operation (Serial Number
Prefixes 1423A and Below) . . . . .
SERVICE . . . . . . . . . . . .
VIII
Introduction : . . . . . .
8-1.
Principles of Operation . . . .
8-5.
Troubleshooting . . . . . .
8-8.
Recommended Test Equipment .
8-12.
Service Aids . . . . . . .
8-14.
Repair . . . . . . . . .
8-23.
8-24.
8-26.
8-28.
8-30.
8-37.
8-39.
8-40.
8-53.
8-60.
8-68.
Factory Selected Components
Etched Circuits . . . . .
Etched Conductor Repair . .
Component Replacement . .
Illustrated Parts Breakdowns .
Basic Circuit Theory . . . .
Binary Circuits and Symbols .
Binary Registers . . . . .
Decade Counters and Symbols
Linear Integrated circuits .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
Page
7-16
7-16
7-16
7-16
7-16
7-16
7-17
7-17
7-17
7-18
7-18
8-1
8-1
8-1
8-1
8-1
8-1
8-3
8-3
8-3
8-3
8-3
8-5
8-5
8-5
8-8
8-9
8-11
iii
Model 8640B Option 004
Service Sheet
Overall Block Diagram . . . . . .
1
FM Circuits and RF Oscillator
2
Troubleshooting . . . . . . .
AM/AGC Circuits and Output Amplifier
3
Troubleshooting . . . . . . .
Counter/Lock Circuits Troubleshooting
4
RF Oscillator (A3) . . . . . . .
5
FM Amplifiers (A3, A5, A9, A13) . .
6
FM Shaping Circuits and Phase Lock
7
Loop Filter (A7, A9) . . . . .
Over-Deviation Detector and Meter
8
Control Circuits (A6, A7, A9) . .
Fixed-Frequency Modulation Oscillator
9
(A1l, A13) . . . . . . . .
9A
Variable-Frequency Modulation
Oscillator for Option 001
(A1l, A13) . . . . . . . .
RF Filters (A10A1) . . . . . . .
10
RF Dividers (A10A2) . . . . . .
11
AGC Amplifiers and Amplitude
12
Modulator
(A26, A26A3, A26A4) . . . . .
RF Amplifier, Pulse Switching, and
13
Step Attenuators (A1A1, A19A1,
A26, A26A1, A26A2) . . .
AM Preamplifier (A13, A26A2) .
14
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. . . .
. . . .
SERVICE SHEETS
Page
8-18
8-20
8-22
8-24
8-26
8-28
8-30
8-32
8-34
8-36
8-38
8-40
8-42
8-44
8-46
Service Sheet
15
16
17
18
19
20
21
22
23
24
25
A
B
C
D
E
F
G
H
Table of Contents
Page
AM Interconnections, RF ON/OFF Switch
and Demodulation Amplifier
(A9, A26A8) . . . . . . . . . . 8-48
RF Vernier (A19A1, A26) . . . . . . . 8-50
Meter Circuits (A2, A4, A6) . . . . . . 8-52
Counter RF Scaler (A8A1, A8A3) . . . . 8-54
Counter Time Base (A8A3, A9) . . . . . 8-56
Up/Down Counter & Display (A8A2, A8A4) . 8-58
Counter Phase Lock Circuits (A8A2) . . . 8-60
Power Supply Circuits
(A12, A14, A20, A22) . . . . . . . 8-62
–5.2V Regulator and Fan Circuits
(A16, A18). . . . . . . . . . . 8-64
Power Supply Mother Board (A17) . . . . 8-67
Modulation/Metering Mother Board (A13) . 8-68
Al and A19 Assemblies Removal
8-70
and Disassembly . . . . . . .
A3 Assembly Removal and Disassembly
A8 Assembly Removal and Disassembly
A9 and All Assemblies Removal
and Disassembly . . . . . . .
Al0 Assembly Removal and Disassembly
A26 Assembly Removal and Disassembly
General Removal Procedures and
Top Internal Views . . . . . .
Rear Panel and Bottom Internal Views
. .
. .
. .
. .
. .
. .
. .
. .
8-72
8-74
8-76
8-78
8-80
8-82
8-85
Table
1-1.
Specifications . . . . . . .
Recommended Test Equipment .
1-2.
Recommended Test Accessories .
1-3.
Recommended Test Abridgements
4-1.
Recommended Test Equipment
4-2.
(Basic Functional Checks) . .
Record of Basic Functional Checks
4-3.
Performance Test Record . . .
4-4.
Factory Selected Components .
5-1.
Post-Repair Test and Adjustments
5-2.
RF Filter Check . . . . . .
5-3.
Part Numbers for Exchange Assemblies . . . 6-2
6-1.
Reference Designations and
6-2.
Abbreviations . . . . . . . . . . . 6-3
Replaceable Parts . . . . . . . . . . 6-5
6-3.
6-5. Part Number-National Stock Number
Cross Reference Index. . . .
A. References . . . . . . . .. A-l
B. Components of END Item List . B-1
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
TABLES
Page
1-8
1-14
1-19
4-2
4-5
4-11
4-94
5-3
5-4
5-32 8-7.
6-45
APPENDIXES
Table
6-4.
7-1.
7-2.
8-1.
8-2.
8-3.
8-4.
8-5.
8-6.
8-8.
8-9.
C.
D.
Code List of Manufacturers . . .
Manual Changes by Serial Number .
Summary of Changes by Component
Etched Circuit Soldering Equipment
Logic Levels . . . . . . . .
Assembly Information Index . . .
Schematic Diagram Notes . . . .
Meter Drive Amplifier Data . . .
Total Count of Time Base Reference
Counters U13, U14, and U15 .
Count Modes of Counters A8A3U13
and U14 . . . . . . . .
Count Modes of Counter A8A3U15
Data Inputs of Decimal Point
Shift Register . . . . . . .
Additional Authorization
Maintenance Allocation .
. .
6-45
. .
. .
. .
. .
.
8-14
8-15
..
. .
8-52
. .
8-56
. .
8-56
. .
8-56
. .
8-56
List N.A.
D-1
iv
Page
7-1
7-2
8-4
8-6
Table of contents
Model 8640B Option 004
ILLUSTRATIONS
1-1.
HP Model 8640B Option 004 Signal Generator
(Option 001) and Accessories Supplied 1-0
Measured Single Sideband Noise vs Offset
1-2.
from Carrier . . . . . . . . .. 1-2
1-3.
Specified Signal-to-Phase Noise Ratio . . .
1-4.
AM Distortion vs AM Rate . . . . . . 1-4
1-5.
Pulsed RF . . . . . . . . . . . .1-5
1-6.
FM Distortion vs FM Rate . . . . . . . 1-5
1-7.
520/1040 MHz Notch Filter . . . . . . 1-20
1-8.
FM Linearity Circuit . . . . . . . . 1-20
1-9.
Noise Phase Lock Circuit . . . . . . . 1-21
2-1.
Line Selector . . . . . . . . . . . 2-1
Power Cables Available , . . . . . . . 2-2
2-2.
2-3.
Preparation for Rack Mounting . . . . . 2-4
3-1.
Lamp Replacement . . . . . . . . . 3-1
Front Panel Controls, Indicators, and
3-2.
connectors . . . . . . . . . .. 3-2
Internal AC/DC Switch , . . . . . . . 3-6
3-3.
3-4.
Rear Panel Controls and Connectors . . . 3-7
Operator's Checks . . . . . . . . . 3-8
3-5.
Setting the Frequency and Amplitude
3-6.
Controls . . . . . . . . . .. 3-13
3-7..
Setting the Modulation Controls. . . . . 3-16
4-1.
Frequency Stability vs Time and Restabiliza-
tion Time Test Setup . . . . . . . 4-16
Frequency Stability vs Temperature
4-2.
Test Setup . . . . . . . . . . .4-18
Frequency Stability vs Line Voltage
4-3.
Test setup . . . . . . . . . . .4-19
Frequency Stability vs Load, Level, and
4-4.
Mode Test Setup. . . . . . . . . 4-20
SubHamonics and Non-Harmonic
4-5.
Spurious Test Setip . . . . 4-24
Single sideband Phase Noise Test Setup . . 4-25
4-6.
Single sideband Broadband Noise
4-7.
Floor Test Setup . . . . . . . . . 4-28
4-8.
Residual AM Test Setup . . . . . . . 4-30
4-9.
Residual FM Test Setup . . . . . . . 4-32
4-10.
Output Level Accuracy Test Setup
(Abbreviated) . . . . . . . . . . 4-34
4-11.
Output Level Accuracy Test Setup
(Complete). . . . . . , . . . . 4-41
Output Level Flatness Test Setup . . . . 4-45
4-12.
4-13.
Output Impedance Test Setup
(Signal Frequency) . . . . . . . . 4-47
4-14.
Output Impedance Test (Broadband) . . . 4-49
Output Leakage Test Setup . . . . . . 4-52
4-15.
4-16.
Internal Modulation Oscillator Test
setup . . . . . . . . . . . . 4-54
v
1-3
Figure
Page
4-17. Internal Modulation Oscillator Distortion
Test Setup . . . . . . . . . . .4-55
4-18. AM 3 dB Bandwidth Test Setup . . . . . 4-56
4-19. AM Distortion Test Setup . . . . . . . 4-58
4-20. AM Sensitivity and Accuracy Test Setup . . 4-60
4-21. Peak Incidental Phase Modulation
Test Setup . . . . . . . . . . .4-63
4-22. Demodulated Output Accuracy Test
Setup . . . . . . . . . . . .4-65
4-23. AM Phase Shift Test Setup . . . . . . 4-69
4-24. Lissajous Display . . . . . . . . . . 4-70
4-25. AM Flatness Test Setup . . . . . . . 4-72
4-26. Pulse Modulation Test Setup . . . . . . 4-74
4-27. Pulse Measurements . . . . . . . . . 4-75
4-28. FM 3 dB Bandwidth Test Setup . . . . . 4-78
4-29. FM Distortion Test Setup . . . . . . . 4-80
4-30. FM Sensitivity and Accuracy Test Setup . . 4-82
4-31. Incidental AM Test Setup . . . . . . . 4-85
4-32. Counter External Sensitivity Test Setup . . 4-87
4-33. Internal Reference Accuracy Test Setup . . 4-88
4-34. Internal Reference Drift Rate (Stability)
Test Setup . . . . . . . . . . .4-90
5-1.
RF Detector Offset Adjustment Test
Setup . . . . . . . . . . . .
5-2.
Output Level Vernier and Meter Adjustment
Test Setup . . . . . . . . . . .
5-3.
Preliminary AM Adjustments . . . . . .
5-4.
AM Accuracy Adjustment Test Setup . . .
VT Pot Adjustment . . . . . . . . .
5-5.
5-6.
Location of RF Oscillator Stop Adjustments.
5-13
5-15
5-17
5-19
5-24
Shown in Maximum ccw Position. Top
View with Instrument Upside Down . .
5-7.
RF Oscillator Output Power Adjustment
Test Setup . . . . . . . . . . .
5-8.
Filter Terminology . . . . . . . . .
5-9.
RF Filter Adjustment Test Setup . . . .
5-26
5-28
5-29
5-30
5-10.256-512 MHz High Band Capacitor
Adjustment Orientation . . . . . . 5-33
5-11. FM Linearity Adjustment Test Setup . . . 5-36
5-12. FM Linearity Display . . . . . . . . 5-38
5-13. FM Linearity Adjustment (Alternate)
Test Setup . . . . . . . . . . .5-39
5-14. FM Sensitivity Adjustment Test Setup . . . 5-41
5-15. Internal Reference Frequency Adjustment
Test Setup . . . . . . . . . . .5-42
6-1.
Cabinet Parts . . . . . . . . . .. 6-43
Type “N” Connector . . . . . . . . 6-44
6-2.
Model 8640B Option 004
Table of Contents
ILLUSTRATIONS (cont'd)
Figure
A26A2 AM Offset and Pulse Switching Assembly
7-1.
Backdating (Change C) . . . . . . . . 7-6
A12 Rectifier Assembly Component Locations
7-2.
Backdating (Change C) . . . . . . . . 7-7
A12 Rectifier Assembly Backdating
7-3.
(Change) . . . . . . . . . . . . 7-7
A3A4 Connector Board Assembly
7-4.
Backdating (Change G) . . . . . . . . 7-9
A8A1 RF Scaler Assembly Component
7-5.
Locations Backdating (Change H) . . . . 7-10
A22 +20V and -20V Regulator Assembly
7-6.
Component Locations Backdating
(Change I) . . . . . . . . . . . .7-12
7-7.
Power Supply Circuits Backdating
(Change I) . . . . . . . . . . . . 7-13
7-8.
A22 +20V and -20V Regulator Assembly
Backdating (Change I) . . . . . . . . 7-14
Modified Line Switch Wiring . . . . . . . 7-18
7-9.
Signal Generator with Circuit Boards on
8-1.
Extenders . . . . . . . . . . . .8-2
Examples of Diode and Transistor
8-2.
Marking Methods . . . . . . . . . . 8-4
Open Collector Output Stage (AND Gate) . . 8-6
8-3.
Binary Symbols . . . . . . . . . . . 8-6
8-4.
Triggered Flip-Flop . . . . . . . . . . 8-7
8-5.
D Flip-Flop . . . . . . . . . . .. 8-7
8-6.
Schmitt Trigger . . . . . . . . . . . 8-7
8-7.
J/K Flip-Flop. . . . . . . . . . . . 8-8
8-8.
Multiple Input J/K Flip-Flop . . . . . . . 8-8
8-9.
8-10.
Binary Latch . . . . . . . . . ...8-9
Binary Shift Register . . . . . . . . . 8-9
8-11.
8-12.
Basic Decade Counter (Scaler) . . . . . . 8-9
8-13.
Programmable Counter . . . . . . . . . 8-10
8-14.
Programmable Up/Down Counter . . . . . 8-12
Operational Amplifier . . . . . . . . . 8-13
8-15.
8-16.
Comparator . . . . . . . . . ...8-14
8-17.
Simplified Block Diagram . . . . . . . . 8-19
Overall Block Diagram . . . . . . . . . 8-19
8-18.
FM Circuits and RF Oscillator Block
8-19.
Diagram . . . . . . . . . . . ..8-21
AM/AGC Circuits and Output Amplifier
8-20.
Block Diagram . . . . . . . . . . 8-23
Counter/Lock Circuits Block Diagram . . . . 8-25
8-21.
P/O A3A4 Connector Board Assembly
8-22.
Component Locations . . . . . . . . 8-27
RF Oscillator Simplified Diagram . . . . . 8-27
8-23.
P/O A3A4 Connector Board Assembly
8-24.
Component Locations . . . . . . . . 8-28
P/O A9 Peak Deviation and Range Switch
8-25.
Assembly Component Locations. . . . . 8-28
Page
Figure
8-26. A5 FM Amplifier Assembly Component
Locations . . . . . . . . . .. 8-29
8-27. FM Amplifiers Schematic Diagram . . . . 8-29
8-28. P/O A7 FM Shaping Assembly
Component Locations . . . . . . 8-31
8-29. FM Shaping Circuits and Phase Lock Loop
Filter Schematic Diagram . . . . . 8-31
8-30. P/O A6 Annunciator Assembly
Component Locations . . . . . . 8-32
8-31. P/O A9 Peak Deviation and Range Switch
Assembly Component Locations. . 8-32
8-32. P/O A7 FM Shaping Assembly
Component Locations . . . . . . 8-33
8-33. Over-Deviation Detector and Meter Control
Circuits Schematic Diagram . . . . . 8-33
8-34. All Fixed-Frequency Modulation Oscillator
Component Locations . . . . . . 8-35
8-35. Fixed-Frequency Modulation Oscillator
Schematic Diagram . . . . . 8-35
8-36. All Variable-Frequency Modulation
Oscillator Assembly (Option 001 )
Component Locations . . . . . . . 8-37
8-37. Variable-Frequency Modulation Oscillator
(Option 001) Schematic Diagram . . . 8-37
8-38. Action of RANGE Switch . . . . . . . 8-38
8-39. A10A1 RF Filter Assembly Component
Locations . . . . . . . . . .. 8-38
8-40. RF Filters Schematic Diagram . . . . . 8-39
8-41. Simplified Logic Diagram of the Filter
Divider Assembly . . . . . . . 8-40
8-42. A10A2 RF Divider Assembly Component
Locations . . . . . . . . . .. 8-41
8-43. RF Dividers Schematic Diagram . . . . . 8-41
8-44. A26A3 Modulator Assembly Component
Locations . . . . . . . . . .. 8-43
8-45. A26A4 AGC Amplifier Assembly
Component Locations . . . . . . 8-43
8-46. AGC Amplifiers and Amplitude Modulator
Schematic Diagram . . . . . . . . 8-43
8-47. A26A1 Power Amplifier and AGC Detector
Assembly Component Locations. . . . 8-45
8-48. P/O A26A2 AM Offset and Pulse Switching
Assembly Component Locations. . . . 8-45
8-49. RF Amplifier, Pulse Switching, and Step
Attenuator Schematic Diagram . . . . 8-45
8-50. P/O A26A2 AM Offset and Pulse Switching
Assembly Component Locations. . . . 8-47
8-51. AM Preamplifier Schematic Diagram . . . 8-47
8-52. A26A8 Demodulation Amplifier
Assembly Component Locations. . . . 8-49
Page
vi
Table of Contents Model 8640B Option 004
ILLUSTRATIONS (cont'd)
Figure
Page
8-53. AM Interconnections, RF ON/OFF Switch
and Demodulation Amplifier
Schematic Diagram . . . . . . . 8-49
8-54. A19A2 RF Vernier Assebly
component Locations . . . . . . 8-51
8-55. RF Vernier Schematic Diagram . . . . . 8-51
8-56. A2 Meter Switch/Detector Assembly
Component Locations . . . . . . . 8-52
8-57. A4 Metir/Annunciator Drive Assembly
Component Locations . . . . . . . 8-53
8-58. P/0 A6 Annunciator Assembly
Component Locations . . . . . . . 8-53
8-59. Meter Circuits Schematic Diagram . . . . 8-53
8-60. A8A1 RF Scaler Assembly
Component locations . . . . . . . 8-55
8-61. P/O A8A3 Time Base Assembly
Component Locations . . . . . . . 8-55
8-62. Counter RF Scaler Schematic Diagram . . 8-55
8-63. P/O A8A3 Time Base Assembly
Component Locations . . . . . . . 8-57
8-64. Counter Time Base Schematic Diagram . . 8-57
8-65. A8A4 Counter Display Assembly
Component locations (P/O A8) . . . . 8-59
8-66. P/O A8A2 Counter/Lock Board
Assembly Component Locations . . . 8-59
8-67. Up/Down Counter and Display
Schematic Diagram . . . . . . . . 8-59
8-68. P/O A8A2 Counter/Lock Board
Assembiy Component Locations . . . 8-61
8-69. Counter Phase Lock Circuits
Schematie Diagram . . . . . . . . 8-61
8-70. Current Foldback . . . . . . . . . 8-62
8-71. A12 Rectifier Assembly
Component Locations . . . . . . . 8-62
8-72. A20 +5.2V and +44.6V Regulator Assembly
Component Locations . . . . . . . 8-63
Figure
Page
8-73. A22 +20V and -20V Regulator Assembly
Component Locations . . . . . . . 8-63
8-74. Power Supply Circuits
Schematic Diagram . . . . . . . . 8-63
8-75. A18 -5.2V Regulator and Fan Driver
Assembly Component Locations. . . . 8-65
8-76. -5.2V Regulator and Fan Circuits
Schematic Diagram . . . . . . . . 8-65
8-77. A17 Power Supply Mother Board Assembly
Component Locations . . . . . . . 8-67
8-78. Power Supply Mother Board
Schematic Diagram . . . . . . . . 8-67
8-79. A13 Modulation/Metering Mother Board
Assembly Component Locations. . . . 8-68
8-80. Modulation/Metering Mother Board
Schematic Diagram . . . . . . . . 8-69
8-81. Al and A19 Output Level Assemblies
Illustrated Parts Breakdown . . . . . 8-71
8-82. RF Oscillator Transistor Preparation . . . 8-72
8-83. RF Oscillator Transistor Orientation . . . 8-72
8-84. A3 RF Oscillator Illustrated
Parts Breakdown . . . . . . . . . 8-73
8-85. A8 Counter/Lock Assembly Illustrated
Parts Breakdown . . . . . . . . . 8-75
8-87. All Variable-Frequency Modulation
Oscillator (Option 001)
Illustrated Parts Breakdown . . . . . 8-77
8-88. Al0 Divider/Filter Assembly
Illustrated Parts Breakdown . . . . . 8-79
8-89. A26 AM/AGC and RF Amplifier
Illustrated Parts Breakdown . . . . . 8-81
8-90. Top Internal Views
(Option 001 Shown) . . . . . . . 8-83
8-91. Rear Panel Views . . . . . . . . . . 8-85
8-92. Bottom Internal Views
(Option 001 Shown) . . . . . . . 8-85
vii
Model 8640B Option 004
To avoid the possibility of injury or death, the
following precautions must be followed before the
instrument is switched on:
If this instrument is to be energized via an
a.
autotransformer for voltage reduction, make sure
that the common terminal is connected to the
earthed pole of the power source.
The power cable plug shall only be
b.
inserted into a socket outlet provided with a
protective earth contact. The protective action
must not be negated by the use of an extension
cord without a protective conductor (grounding).
c.
Before switching on the instrument, the
protective earth terminal of the instrument must
be connected to a protective conductor of the
power cord. This is accomplished by ensuring that
the instrument’s internal earth terminal is correctly
connected to the instrument’s chassis and that the
power
Sheet 22).
Whenever it is likely that the protection has been
impaired, the instrument must be made inoperative
and be secured against any unintended operation.
Any interruption of the protective (grounding)
conductor inside or outside the instrument or
disconnection of the protective earth terminal is
likely to make the instrument dangerous. Intentional interruption is prohibited.
HIGH VOLTAGE
Any adjustment, maintenance, and repair of the
opened instrument under voltage should be
avoided as much as possible and, if inevitable,
should be carried out only by a skilled person who
is aware of the hazard involved.
cord is wired correctly (see Service
Cautions/Warnings
GROUNDING
Any interruption of the protective (grounding)
conductor inside or outside the instrument is likely
to cause damage to the instrument. To avoid
damage, this instrument and all line powered
devices connected to it must be connected to the
same earth ground (see Section II).
LINE VOLTAGE
Be sure to select the correct fuse rating for the
selected line voltage (see
SELECTION in Section II); fuse ratings are listed
on the fuse compartment.
To prevent damage to the instrument, make the
line voltage selection BEFORE connecting the line
power. Also ensure that the line power cord is
connected to a line power socket that is provided
with a protective earth contact.
SAFETY
To avoid the possibility of damage to test equip-
ment, read completely through each test before
starting it. Make any preliminary control settings
necessary for correct test equipment operation.
COUNTER INPUT
Do not apply a dc
COUNTER INPUT.
SEMI-RIGID COAX
While working with
coaxial cables-in the generator, do NOT bend the
cables more than necessary. Do NOT torque the
RF connectors to more than 2 INCH-POUNDS.
voltage or >+15 dBm to
and around the semi-rigid
LINE VOLTAGE
Capacitors inside the instrument may still be
charged even if the instrument has been disconnected from its source of supply.
FUSES
Make sure that only fuses with the required rated
current and of the specified type (normal blow,
time delay, etc.) are used for replacement. The use
of repaired fuses and the short-circuiting of fuseholders must be avoided.
viii
SECTION O
TM 11-6625-2780-14&P
0-1.Scope
This manual describes Signal Generators SG-1112(V)1/U and SG-1112(v)2/U and provides instructions for
operation and maintenance. Throughout this manual, the
SG-1112(v)1/U is referred to as Model 8640B Option
004 and the SG-ll12(v)/U is referred to as Model
8640B Optin 001. A Manufacturer's Part Number to
National Stock Number Coss Reference Index for the
SG-1112(v)1/U and the SG-ll12(V)2/U is given in
Section VI of this manual.
0-2. Indexes of Publications
a. DA Pam 310-4.
Refer to the latest issue of DA Pam
310-4 to determine whether there are new editions,
changes, or additional publications pertaining to the
equipment.
b. DA Pam .310- 7.
Refer to DA Pam 310-7 to deter-
mine whether there are modification work orders
(MWO's)pertaining to the equipment.
0-3. Maintenance Forms, Records, and Re-
ports
a. Reports of Maintenance and Unsatisfactory Equip-
ment. Department of the Army forms and procedures
used for equipment maintenance will be those described
by TM 38-750, The Army Maintenance Management
System.
b. Report of Packaging and Handling Deficiencies.
Fill
out and forward Standard Form 364 (Report of Dis-
crepancy (ROD)) as prescribed in AR 735-1l-2/NAVSUPINST 4440.127E/AFR 400-54/MCO 4430.3E
and DLAR 4140.55.
c. Discrepancy in Shipment Report (DISREP) (SF
361).
Fill out and forward Discrepancy in Shipment Report (DISREP) (SF 361) as prescribed in AR 55-38/NAVSUPINST 4610.33B/AFR 75-18/MCO
P4610.19C, and DLAR 4500.15.
0-4. Reporting Equipment Improvement
Recommendations (EIR)
If your equipment needs improvement, let us know, Send
us an EIR. You, the user, are the only one who can tell us
what you don’t like about your equipment. Let us know
what you don’t like about the design. Tell us why a
procedure is hard to perform. Put it on an SF 368 (Quality
Deficiency Report). Mail it to Commander, US Army
Communications and Electronics Materiel Redness
Command and Fort Monmouth, ATTN: DRSEL-MEMQ, Fort Monmouth, NJ 07703. We’ll send you a reply.
0-5. Administrative Storage
Administrative storage of equipment issued to and used
by Army activities shall be in accordance with paragraph
2-22.
0-6. Destruction of Army Electronics
Materiel
Destruction of Army electronics materiel to prevent
enemy use shall be in accordance with TM 750-244-2.
0-1
General Information
Model 8640B Option 004
MODEL 8640B OPTION 004
RACK MOUNTING KIT
DEMO CAL LABELS
Figure 1-1. HP Model 8640B Option 004 Signal Generator (Option 001) and Accessories Supplied
1-0
LINE POWER CABLE
Model 8640B Option 004
General Information
SECTION I
GENERAL INFORMATION
1-1. INTRODUCTION
1-2. This manual contains operating and service
information for the Hewlett-Packard Model 8640B
Option 004 Signal Generator. The Signal Generator
(with variable frequency modulation oscillator
Option 001) is shown in Figure 1-1 with all of its
externally supplied accessories.
1-3. This section of the manual describes the
instruments documented by this manual and covers
instrument description, options, accessories, specifications and other basic information. The other
sections provide the following:
Section II, Installation:
information about initial
inspection, preparation for use, and storage and
shipment.
Section III, Operation:
information about panel
features, and provides operating checks, instructions, and maintenance information.
Section IV, Performance Tests:
information required to check basic instrument functions and to
verify that the instrument is performing as specified in Table 1-1.
Section V, Adjustments:
information required to
properly adjust and align the instrument.
1-5. Deleted.
1-6. SPECIFICATIONS
1-7. Instrument specifications are listed in Table
1-1. These specifications are the performance
standards or limits against which the instrument
can be tested. Paragraph 1-19 lists some supple-
mental performance characteristics. Supplemental
characteristics are not specifications but are typical
characteristics included as additional information
for the user.
1-8. INSTRUMENTS COVERED BY MANUAL
1-9.
This instrument has a two-part serial number.
The first four digits and the letter comprise the
serial number prefix which defines the instrument
configuration. The last five digits form the sequential suffix that is unique to each instrument. The
contents of this manual apply directly to instruments having the serial prefixes 1435A and
1438A.
Section VI, Replaceable Parts:
ordering informa-
tion for all replaceable parts and assemblies.
Section VII, Manual Changes:
information to revise this manual to document earlier configurations
of the instrument and information suggesting instrument modifications.
Section VIII, Service:
information required to re-
pair the instrument.
1-4. Deleted.
1-10. An instrument manufactured after the print-
ing of this manual may have a serial prefix that is
different from that indicated above. If
80, refer to Section VII and make the
applicable manual changes.
1.11.
1-1
General Information
1-12. For information concerning a serial number
prefix not covered in this manual,
contact your nearest Hewlett-
Packard office.
1-13. GENERAL DESCRIPTION
1-14. The Model 8640B Option 004 Signal Generator is an adaptation of the Model 8640B specifically designed for testing ILS, VOR, and UHF
communications receivers used in aviation as well
as general Purpose HF, VHF and UHF receivers.
The Signal Generator covers the frequency range
500 kHz to 512 MHz (450 kHz to 550 MHz with
band over-range)
and can be extended to
1100 MHz with an external doubler. An optional
variable audio oscillator is also available to extend
the CW output range of the generator down to
20 Hz.
Model 8640B Option 004
1-18. Other significant features are extremely low
noise, built in phase lock and counter, and front
panel controls designed
for operating convenience
and flexibility.
1-19.
PERFORMANCE
1-20.
Spectral Purity
1-21.
The basic frequency source of the
CHARACTERISTICS
Signal
Generator is a mechanically-tuned high-Q cavity
oscillator that operates over the frequency range
230-550 MHz. This oscillator has an inherent
stability of better than 10 ppm/10 min and exceptionally low noise characteristics. The lower 9
frequency ranges are obtained by dividing the basic
oscillator frequency and filtering the unwanted
harmonics. Using this technique, sub-harmonic and
non harmonic-spurious signals are virtually eliminated. A band overlap of 7% to 10% adds conven-
ience when operating near the nominal band edges.
1-15. This solid-state generator has an output level
range of +15 to -142 dBm (1.3V to 0.018 µV) that
is calibrated and metered. The output is leveled to
within ±0.5 dB from 108 to 336 MHz and within
±0.75 dB across the full frequency range of the
instrument.
1-16. The generator also provides AM, FM and
pulse modulation for a wide range of receiver test
applications. AM and FM can be performed
independently or simultaneously in either the
internal or external modes. This modulation is
calibrated and metered for direct readout under all
operating conditions. External pulse modulation is
also available.
1-17. For avionics testing (VOR/ILS), an external
audio generator’ is required to provide the com-
posite modulation.
When used with a suitable
external audio generator the Option 004 has flat
AM response and minimum phase shift from 30 Hz
to 10 kHz as well as constant group delay between
9 kHz and 11 kHz for accurate VOR and ILS
testing. A front panel jack also provides a very
accurate demodulated audio signal (AC/DC
0-1 Vrms or AC only 0-5 Vrms) for precise AM
settings.
1
e.g., Bendix RVG 33A — VOR Audio Generator
Collins 479S-4A
Tel-Instrument
Corporation T-20A — VOR/ILS Audio Signal Generator
RIG 32A
— ILS Audio Generator
— ILS Audio Signal Generator
Figure 1-2. Measured Single Sideband Noise vs
Offset from Carrier. (Stated in a 1 Hz Bandwidth
at 256 and 512 MHz Carrier Frequencies on
256-512 MHz Band. ) Markers indicate specified
limits.
1-22. Frequency within a band is selected with a
FREQUENCY TUNE control of approximately 8
turns (see Figure 3-2) for fast selection of the
desired output frequency. A mechanical FINE
TUNE control has a tuning range of 1000 ppm for
precision frequency setting.
1-2
Model 8640B Option 004
General Information
1-23. Restabilization time is short when tuning the
frequency across any one band. The total frequency excursion after any frequency change is
typically <20 ppm and within 15 minutes the
output has restabilized to the specified
10 ppm/10 min. When not phase locked, no restabilization time is required when switching frequency
binds for a fixed position cm the frequency tune
control.
1-24. Noise performance of the generator is excellent. The high-Q cavity oscillator has been
optimized with use of a low noise microwave
transistor for a spectrally pure output signal.
Figure 1-2 shows the typical measured single-sideband noise performance in a 1 Hz bandwidth for
various offsets from a (256 and 512 MHz) carrier.
The low close-in noise characteristic is ideally
suited for the stringent adjacent channel tests that
are commonly made on a wide variety of
communication receivers.
1-25. Figure 1-3 gives a plot of the specified SSB
noise perfomance for a 20 kHz offset from the
carrier for the 256-512 MHz band. From 230 to
450 MHz, noise is >130 dB/Hz below the carrier
level and rises to 122 dB/Hz at 500 MHz. This
signal-to-noise ratio decreases by approximately
6 dB for each division of the output frequency
down to the broadband noise floor of better than
130 dB/Hz. This exceptional noise performance is
also preserved in the phase lock mode and only
slightly degraded during FM.
1-26.
Frequency Counter
1-27. The Signal Generator has a built-in 550 MHz
frequency counter and phase lock synchronizer.
The 6-digit light-emitting diode (LED) display gives
a normal resolution of 10 kHz at 500 MHz and
10 Hz at 500 kHz. The resolution can be increased
using the X10 or X100 EXPAND buttons near the
display. In the X100 EXPAND mode, the resolution is 100 Hz at 500 MHz and 0.1 Hz at
500 kHz.
1-28. This resolution, combined with the high
stability of the generator, allows precise frequency
selection and meaningful measurements on high
performance receiver systems. When selecting the
external doubler band, the counter displays the
doubled output frequency directly.
1-29. When using the expand modes, it is possible
for significant digits or the decimal points to be
shifted off the display. When this occurs, an
OVERFLOW light reminds the operator that the
display is not showing the complete output fre-
quency.
1-30. The built-in counter can also be used to
count external input signals from 1 Hz to 550 MHz
and eliminates the need for a separate frequency
counter in many measurement systems. Input
sensitivity is <100 mV into 50. Using the EXPAND buttons, it is possible to achieve a resolution
of 1 Hz in the 0-10 MHz EXTERNAL count mode
or 100 Hz in the 0-550 MHz mode.
Figure 1-3. Specified Signal-to-Phase Noise Ratio
at 20 kHz Offset vsus Carrier Frequency (MHz).
(Stated in a 1 Hz Bandwidth.) For lower bands,
phase-noise decreases approximately 6 dB per fre-
quency division down to the broadband noise
floor.
1-31. Phase-Lock Mode
1-32. Also included in the Signal Generator is a
built-in phase lock synchronizer that locks the RF
output frequency to the crystal time base used in
the counter. In this locked mode, output stability
is better than 5 x 10
-8
/h while the spectral purity
and FM capability of the unlocked mode are
preserved. For higher stability, it is possible to lock
to an externally applied 5 MHz standard. Two
Model 8640B’s can also be locked to a common
timebase reference for performing various two-tone
measurements.
1-33. Phase locking the generator is simple - just
push the front panel LOCK button. The generator
is then locked to the frequency shown on the
LED
display. If lock is broken (for example by tuning
1-3
General Information
Model 8640B Option 004
to a new output frequency or during warmup),
there is an immediate indication: the LED display
flashes. The generator can be relocked by releasing
the LOCK button and then relocking.
1-34. The generator can be locked in the normal
mode of the counter or in the X10 EXPAND mode
if the OVERFLOW light is not on. It is normally
not possible nor recommended to lock in the X100
EXPAND mode or when counting external inputs.
Maximum resolution in the locked mode is 1 kHz
at 500 MHz, increasing to 1 Hz at 500 kHz.
1-35. If an output frequency between adjacent
counter indications is required, a TIME BASE
VERNIER is provided with a range of ±20 ppm.
This fine tunes the internal crystal time base and
sets the output frequency between adjacent counts
(i.e., the least significant digits of the display). This
gives continuous coverage of all output frequencies
even in the phase lock mode. An UNCAL annunciator near the vernier will light when this mode has
been selected indicating that the counter display is
incorrect.
1-41. AM up to rates of 50 kHz is possible
depending on carrier frequency and modulation
depths. Distortion is specified at 400 Hz and
1000 Hz to be <1% up to 50% AM, <3% to 90%
AM. Figure 1-4 shows measured AM distortion
characteristics for other modulation frequencies.
Note that for 0-50% AM, distortion is <1% to
approximately 90 kHz for an output frequency of
200 MHz.
1-36. When phase locked, the narrow bandwidth
of the phase lock loop (<5 Hz) preserves full FM
capabilities down to rates of 50 Hz and assures no
degradation in noise from the unlocked mode
(residual FM is not changed by phase locking).
1-37.
Amplitude Modulation
1-38. AM is variable from 0 to 100% with the
rates, accuracy, and low incidental FM required for
the most stringent AM applications. The front
panel meter gives a direct readout of percent AM in
either the internal or external mode and autoranges
the 0-100% scale to 0-30% for improved nettability
at low modulation depths.
1-39. For precision measurement of AM, the front
panel DEMOD OUTPUT jack provides a demodulated AM signal (either 0 - 1 Vrms or 0 -5 Vrms)
which is directly proportional to percent AM. The
DEMOD CAL label lists values of this voltage by
which percent AM can be set very accurately
(within 1%) with an ac voltmeter. The label was
prepared when the instrument was calibrated. A
new label should be prepared whenever the generator is recalibrated.
1-40. DEMOD OUTPUT can also be connected to
the Demod Input of some modulation sources for
sensing the phase relationship of the output RF
envelope and the input modulating signal.
Figure 1-4. AM distortion us AM rate measured at
200 MHz and +10 dBm, but applies to all bands.
(Supplemental information only.)
1-42.
Pulse Modulation
1-43. Also included on the AM function switch is
a position for external PULSE modulation. In this
mode, pulse inputs with repetition rates to
500 kHz and widths down to 2 µ
S can be applied
to modulate the RF carrier. Rise and fall times
vary with output frequency down to <1 µ
S from 8
to 512 MHz.
1-44. Pulse inputs turn the RF on. Hence with no
pulse inputs the RF will read approximately zero
on the built-in level meter. For pulse inputs greater
than 0.5V, the RF output is on, calibration is
preserved and the level meter reads the pulse-on
power of the RF output. For repetition rates
below that specified, the pulsed RF output is still
available but the pulse-on level is no longer
calibrated or metered.
1-45.
Frequency Modulation
1-46. FM is calibrated, metered and constant with
RF frequency and band changes. Peak deviations to
at least 0.57. of carrier frequency are available (i.e.,
1% of the minimum frequency in each octave
band). On the 256-512 MHz band, for example,
1-4
Model 8640B Option 004
Figure 1-5. Pulsed RF 20 MHz Carrier Frequency
-
at
400 kHz Pulse Rate and 1 µs Pulse Width.
the maximum
deviation is 2.56 MHz peak or
5.12 MHz peak-to-peak. With this wide deviation
capability, it is possible to sweep the generator,
using the dc coupled FM mode and a sawtooth
input, to test and align IF filters and
discriminators.
General Information
available separately at the front panel and can be
varied in level from 3V to <20 mV into 600
Ω.
This audio oscillator, Option 001, extends the
usable CW range of the generator down to 20 Hz.
1-51. Multi-Function Meter and Annunciators
1-52. The front panel meter on the Signal Gener-
ator monitors the RF output level in dBm and
volts, the
peak deviation in kHz or MHz. The accuracy of
this meter is usually better then ±3% of reading.
Pushbuttons select the meter function, and scale
lights indicate the range on which the meter
reading should be made. For RF output level and
AM%, the scales autorange for better resolution.
For FM, the appropriate scale is selected by the
PEAK DEVIATION range switch.
AM modulation percentage, and the FM
1-53. Also provided are three front panel annunciators that indicate when certain settings of RF
level and modulation controls exceed specified
limits. Besides giving a warning indication, the
annunciators instruct the operator about returning
the instrument to proper operation.
1-47. For narrowband FM applications, a minimum full scale deviation of 5 kHz is provided on
the meter and the PEAK DEVIATION range
switch. When switching from the CWto FM mode,
there is negligible shift in carrier frequency and no
degradation in spectral purity for these narrow
deviations. With the generator in the phase lock
mode it is
possible to modulate at rates down to
50 Hz while maintaining accurate FM calibration
and the carrier drift stability of a crystal oscillator.
Using the unlocked mode, it is possible to modul-
Z
ate from dc to 250 kH
with a carrier drift stability
of <10 ppm/10 min.
1-48.
Standard and Optional Audio Oscillators
1-49. Standard tones for internal modulation are
400 Hz and 1000 Hz. These tones are also available
at the front panel and can be varied in output level
from 1 V to <10 mV into 600 Ω. Total harmonic
distortion is typically <0.25%.
1-50. Optionally available on the Signal Generator
is a built-in variable frequency oscillator covering
the range 20 Hz to 600 kHz (fixed tones of 400 Hz
and 1000 Hz are also provided). This internal
oscillator has a wide range of standard modulation
frequencies and is useful for testing receiver audio
bandwidth. Output from this modulation souce is
Figure 1-6. FM distortion vs FM rate measured in
the 8-16 MHz band, but applies to all bands (sup-
plemental information only).
1-54. The REDUCE PEAK POWER annunciator
lights whenever the combined settings of RF
output and AM modulation levels exceed allowable
knits. The specification allows for up to 100% AM
on all RF output ranges except the +16 dBm range.
On the +16 dBm range RF levels with up to 50%
AM are normally possible before the annunciator
will light. When the annunciator lights it is necea-
1-5
General Information Model 8640B Option 004
sary to reduce either the OUTPUT LEVEL 10 dB
switch or the AM MODULATION control.
1-55. The REDUCE PEAK DEVIATION annunciator lights whenever the PEAK DEVIATION
RANGE switch has been set to exceed the allowable limits for any output FREQUENCY RANGE.
The specification allows for a maximum peak
deviation of 1% of the minimum frequency in each
band (e.g., 2.56 MHz on the 256-512 MHz band).
When the annunciator lights, the FM is automatically turned off and the FM meter reads zero.
1-56. The REDUCE FM VERNIER annunciator
lights whenever the FM input and FM vernier
setting combine to exceed the 1 volt drive level
required to achieve the maximum deviation indicated on the PEAK DEVIATION range switch.
When this occurs, either the FM vernier or the
amplitude of the incoming modulation signal
should be reduced to obtain specified FM
performance.
1-57. Output Level
1-58. The wide output range of the generator is
achieved with a 20 dB step attenuator, a 1 dB step
attenuator and a 2 dB vernier. Output levels can be
read directly on the attenuator dials or (for greater
accuracy) on the autoranging meter. The meter
scales are automatically selected to give the maxi-
mum indicator resolution for any output level.
1-59. The maximum output level of +15 dBm
permits high level tests on receiver IF’s, amplifiers,
and mixers without additional power amplifica-
tion. At the same time, extremely low leakage
ensures receiver sensitivity measurements down to
levels of 0.03 µV in a shielded system.
1-60. For improved accuracy at low output levels,
the meter, in conjunction with the attenuators, is
factory-calibrated against a precision standard to
remove much of the error that is accumulated from
the attenuator’s steps. Using a power meter and
calibrating the output for one output frequency
and vernier setting, it is then possible to make
sensitivity measurements to better than ±1 dB
accuracy down to output levels of --127 dBm.
1-61. OPTIONS
1-62. Option 001. Option 001 (covered in this
manual ) provides a modulation oscillator that is
continuously settable from 20 Hz to 600 kHz. The
oscillator can also be set for 400 Hz or 1 kHz fixed
tones.
1-63. Option 002. Option 002 (an internal fre-
quency doubler available in the standard Model
8640B) is not compatible with the Model 8640B
Option 004 and thus is not covered in this manual.
1-64. Option 003. Option 003 (either factory built
or retrofitted) protects the generator’s output circuits from accidental applications of reverse power
up to 25 watts. Option 003 is documented in a
separate manual supplement.
1-65. ACCESSORIES SUPPLIED
1-66. The Model 8640B Option 004 is supplied
with the following accessories (they are shown in
Figure 1-1):
Rack Mounting Kit (HP 5060-8740)
Line Power Cable (HP 8120-1378)
2 Amp Fuse (HP 2110-0002)
1.25 Amp Fuse (HP 2110-0094)
Demod Cal Labels (HP 7120-4244)
1-67. The rack mounting kit, the cable, and the
fuses are fully described in Section II.
1-68. The following accessories are mounted inside
the instrument’s chassis and are available for
adjustment and repair (for more information, see
Sections V and VIII):
Combination Wrench (HP 5001-0135)
Spare fuses for power supply circuit boards
30-pin Extender Board (HP 08640-60036)
1-69. EQUIPMENT AVAILABLE
1-70. Fuseholder. The HP Model 11509A Fuse-
holder attaches to the RF OUT jack and prevents
accidental damage to the generator’s output attenuator by externally applied R F. It is primarily
used when testing transceivers.
The fuseholder may not protect the output amplifier against a fast pulse of
reverse power on the top two ranges, of
the OUTPUT LEVEL 10 dB switch.
1-71. Termination. The HP Model 11507A Termi-
nation maintains the generator’s output level calibration when the output is connected to load
impedances other than 50 ohms. It can provide
source impedances of 25 and 5 ohms, and it can
simulate a broadcast-band dummy antenna. The
frequency range is 50 kHz to 65 MHz.
1-6
Model 8640B Option 004
General Information
1-72. 75 Ohm Adapter. The HP Model 11687A 50
to 75 Ohm Adapter connects to the generator’s output to provide a source impedance of 75 ohms.
1-73. Doubler. The HP Model 11690A Doubler
extends the usable frequency range of the generator one octave to 1024 MHz (actually to
1100 MHz with 7% frequency over-range). Conver-
sion low in the doubler is typically <13 dB.
1-74.
Mixer. The HP Model 10514A Double Bal-
ancedi Mixer can be used at the generator's output
as a nanosecond pulse modulator or as a balanced
mixer.
1-75. Protective Cover. The HP 5060-8767 Con-
trol Panel Cover protects the panel from dust and
impact damage.
1-76. SERVICE AND USER AIDS
1-77. Video Tapes. Video tapes covering instru-
ment use, application, and service are available.
Contact the nearest Hewlett-Packard Sales and
Service Office for a list of presently available tapes.
1-78. Application Notes. Informative notes con-
cerning the use of signal generators are also
available from the nearest Hewlett-Packard Sales
and Service Office.
1-79. Service Notes. Hewlett-Packard makes de-
sign improvements to its current line of instrument on a continuing basis. Many of these
improvements can be incorporated in earlier produced instruments. Modification and general ser-
vice information is passed on in the form of Service
Notes. To obtain the Service Notes contact the
nearest Hewlett-Packard Sales and Service Office.
1-80. Deleted.
1-81. Deleted.
1-82. TEST EQUIPMENT REQUIRED
1-83. Tables 1-2 and 1-3 list the test equipment
and accessories required to check, adjust and repair
the Model 8640B Option 004. (Table 4-2 is a
separate list of relatively inexpensive, commonly
available test equipment for the Basic Functional
Check only.) Refer to the Mac in Appendix
D for Army test equipment requirements.
NOTE
The safety classification of this instru-
ment is Safety Class I. It has been
designed and tested according to IEC
Publication 348 SAFETY REQUIREMENTS FOR ELECTRONIC MEASURING APPARATUS and has been sup-
plied in safe condition. The instruction
manual contains in formation, warnings,
and cautions which must be followed by
the user to ensure safe operation and to
retain the instrument in safe condition.
1-7
Table 1-1.
1-8
Model 8640B Option 004
Table 1-1. Specifications (2 of 6)
FREQUENCY CHARACTERISTICS (Cont’d)
Restabilization Time:
After frequency
change
After band change
After 1 min in RF
OFF Mode
Harmonics:
(on IV, +10 dBm, output range and below)
>35 dB below fundamental of 0.5 to 128 MHz.
>30 dB below fundamental of 128 to 512 MHz.
Subharmonic and Nonharmonic Spurious:
frequencies within 15 kHz of carrier whose effects
are specified in Residual AM and FM): >100 dB
below carrier.
Noise:
Averaged rms noise level below carrier stated
in a 1 Hz bandwidth.
SSB Phase Noise at 20 kHz offset from carrier. (See
Figures 1-2 and 1-3.)
256 MHz to 512 MHz: >130 dB from 230 to
450 MHz increasing linearly to >122 dB down
at. 550 MHz.
0.5 MHz to 256 MHz: Decreases approximately
6 dB for each divided frequency range until it
reaches SSB Broadband Noise Floor of
>140 dB.
SSB Broadband Noise Floor greater than 1 MHz
offset from carrier (see Figures 1-2 and 1-3):
>130 dB down.
<15 min
2
<10 min
SPECTRAL PURITY
Residual AM:
(excluding
Residual FM:
General Information
Normal
Locked
l
<1 min
after
None
relocking
to be within
0.1 ppm of
steady-state
frequency
(Averaged rms)
Post-detection Noise Bandwidth
300 Hz to 3 kHz
>85 dB down
20 Hz to 15 kHz
>78 dB down
(Averaged rms)
CW and up to Up to maxi-
1/8 maximum mum allowable
allowable peak peak
deviation deviation
Post-detection
Noise
Bandwidth
230 to 550 MHz
Note:
Residual FM decreases by approximately 1/2 for
300 Hz 20 Hz 300 Hz 20 Hz
to to to to
3 kHz 15 kHz 3 kHz 15 kHz
<5 Hz <15 Hz
<15 Hz <30HZ
each divided frequency range until limited by broad-
band noise floor. This limit for 300 Hz to 3 kHz is
about 1 Hz, and for 20 Hz to 15 kHz is about 4 Hz.
These are measured values in the 230 to 550 MHz
range
and calculated for divided ranges, knowing the
noise distribution.
1
OUTPUT CHARACTERISTICS
Range:
+15 dBm to –142 dBm (1.3V to 0.018 µV).
Level Flatness:
Attenuators: a 10 dB step attenuator, and a 1 dB <±0.75 dB from 0.5 to 512 MHz referred to output
step attenuator with vernier allow selection of
any output level over the full output level range.
Vernier: >2 dB continuously variable from a CAL
detent position.
1
These specifications are given for the 8640B Option 004 internal reference. when using an external reference. drift in the locked mode
will depend on the external reference characteristics.
2
This specification apply only if the RF ON/OFF switch has been wired to turn the RF Oscillator off.
at 190 MHz.
<±0.5 dB from 108 to 336 MHz referred to output
at 190 MHz.
(Flatness applies to +10 to -10 dBm.)
1-9
General Information
Model 8640B Option 004
Table 1-1. Specifications (3 of 6)
OUTPUT CHARACTERISTICS (Cont’d)
Impedance:
50
Ω,
ac coupled, VSWR. <2.0 on 3V and
IV output ranges; <1.3 on all other ranges.
Reverse Power Damage Level:
40 Vdc maximum.
20 dBm maximum on 3V and IV output ranges;
27 dBm maximum on all other ranges.
Reverse Power Protection (Option 003):
Protects signal
generator from accidental applications of up to
25 watts (+44 dBm) of RF power (between dc and
1100 MHz) into generator output.
Auxiliary Output:
Ω,
into 50
Rear panel BNC output is >–5 dBm
source impedance is approximately 500
Ω.
Leakage: (With all unused outputs terminated properly.)
Leakage limits are below those specified in MIL-I6181D. Furthermore, less than 3 µV is induced in a
2-turn, l-inch diameter loop 1 inch away from any
surface and measured into a 50 Ω receiver. This permits receiver sensitivity measurements to at least
<0.03 µV in a shielded system.
MODULATION CHARACTERISTICS
General
Types: Internal AM and FM.
External AM, FM, and PULSE.
Simultaneous AM and FM, or PULSE and FM.
Internal Modulation Sources: (independently adjustable
output is available at front panel).
Standard:
Frequency: Fixed 400 Hz and 1 kHz, ±2%.
Output Level: Indicated 10 mVrms to 1 Vrms,
into 600
Ω
Level Accuracy:
Note: Level Accuracy error consists of allowances
for meter accuracy, detector linearity, temperature
flatness, attenuator accuracy, and twice the measurement error. All but the attenuator accuracy and the
measurement error can be calibrated out with a
power meter at a fixed frequency and a fixed vernier
setting.
Optional: (Internal Variable Audio Oscillator,
Option 001).
Frequency: Variable 20 Hz to 600 kHz,±l0%
in 5 decade continuous bands plus fixed
400 Hz and 1 kHz ±3%.
Output Level: 20 mVrms to 3 Vrms into
600
Ω.
Total Harmonic Distortion:
< 0.25% 400 Hz and 1 kHz fixed tones
< 0.5%
< 1.0%
20 Hz to 2 kHz
2 kHz to 600 kHz
Amplitude Modulation
(Not applicable when OUTPUT LEVEL 10 dB switch in +16 dBm position).
Depth: 0 to 100%.
AM Rates: INT and EXT ac; 20 Hz to AM 3 dB band-
width. EXT dc; dc to AM 3 dB bandwidth.
1
AM is possible in tbe +16 dBm output range with AM depths
typically up to 50%, however DEMOD OUTPUT is not calibrated in this range and degradation of other AM specifications
should be expected.
1-10
1
AM 3 dB Bandwidth: (See Figure 1-4.)
Frequency
Bands
0.5-2 MHz
2-8 MHz
8-512 MHz
0 to
50% AM
15 kHz
30 kHz
50 kHz
50 to
90% AM
12.5 kHz
20 kHz
35 kHz
Table 1-1.
1-11
General Information
Model 8640B Option 004
Table 1-1. Specifications (5 of 6)
MODULATION CHARACTERISTICS (Cont’d)
Pulse Modulation
Frequency Bands (MHz)
Rise and Fall Times
Pulse Repetition Rate
Pulse Width Minimum
for level accuracy within
1
dB of CW (>0.1% duty cycle)
Pulse ON/OFF ratio
Peak Input Required
Deviation:
Maximum allowable deviation equals 1% of
lowest frequency in each band as below.
Frequency Band
(MHz)
0.5-1
1-2
2-4
4-8
8-16
16-32
32-64
64-128
128-256
256-512
512-1024
Maximum Peak
Deviation (kHz)
5
10
20
40
80
160
320
640
1280
2560
5120
2
<1
µs
32-512
µs
50
Hz
500 kHz
to
0.5-1
<9
µs
50 Hz
50 kHz
10
µs
1-2
<4
to
µs
2-8
<2
µs
50 Hz to
100 kHz
5
µs
>40
dB
8-32
50 Hz
to
250 kHz
Nominally > +0.5V (5V max) sinewave or pulse return to zero,
into 50
Ω.
Frequency
Modulation
FM Distortion:
(at 400 Hz and 1 kHz rates) See
Figure 1-6.
<1% for deviations up to 1/8 maximum allowable.
<3% for maximum allowable deviation.
External FM Sensitivity:
1 volt peak yields maximum
deviation indicated on PEAK DEVIATION switch
with FM vernier at full cw position.
External FM Sensitivity Accuracy:
±6% from 15 to 35°C
for FM excluding maximum peak deviation position.
Maximum peak deviation position, ±9% typically.
Indicated FM Accuracy:
(400 Hz and 1 kHz rates using
internal meter) ±10% of meter reading (for greater
than 10% of full scale).
FM 3 dB Bandwidth:
1
Internal and External ac; 20 Hz to 250 kHz.
External dc; dc to 250 kHz.
1
With 8640B Option 004 in LOCKED MODE, external FM is possible only for rates greater than 50 Hz.
Incidental AM:
<0.5% AM for FM up to 1/8 maximum allowable
deviation.
<1% AM for FM at maximum allowable deviation.
(at 400 Hz and 1 kHz rates)
1-12
Table 1-1.
1-13
Table 1-2.
1-14
Table 1-2.
1-15
Table 1-2.
Figure 1-9
Figure 1-8
1-16
Table 1-2.
1-17
Table 1-2.
1-18
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