Hewlett-Packard 8640B Signal Generator Technical Manual

The 8640B Signal Generator is a high-performance signal generator designed for use in the PATRIOT Air Defense Guided Missile System. It is capable of generating a wide range of frequencies (10 kHz to 26.5 GHz), modulation formats (AM, FM, Pulse, and more), and output levels. The 8640B's high spectral purity and stability make it ideal for testing and characterizing various electronic circuits. This device can be used to test the performance of receivers, amplifiers, and other electronic components across a broad range of frequencies.

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TECHNICAL MANUAL

OPERATOR, ORGANIZATIONAL,

DIRECT SUPPORT, AND GENERAL

SUPPORT MAI'NTENANCE MANUAL

(INCLUDING REPAIR PARTS)

FOR

8640B SIGNAL GENERATOR

(INCLUDING OPTION 001)

(PATRIOT AIR DEFENSE GUIDED MISSILE SYSTEM)

HEADQUARTERS, DEPARTMENT OF THE ARMY

SEPTEMBER 1986

TM 9-4935-601-14-7&P

TM 9-4935-601-14-7&P

WARNING

DANGEROUS VOLTAGE is used to operate this equipment

DEATH ON CONTACT may result if safety precautions are not observed.

Never work on electronic equipment unless there is someone nearby who is familiar with the operation and hazards of the equipment and is able to give first aid. When the technician is aided by operators, he must warn them about dangerous areas.

When possible, shut off power to equipment before beginning work on equipment. Ground every capacitor likely to hold a dangerous potential. When working inside equipment, after the power has been turned off, always ground every part before touching it.

Be careful not to contact high-voltage connections when installing or operating this equipment.

When possible, keep one hand away from equipment to reduce the hazard of current flowing through the vital organs of the body.

Read FM 21-11, First Aid for Soldiers, and learn how to administer artificial respiration.

WARNING

Do not be misled by the term "low voltage." Under adverse conditions, potentials as low as 50 volts may cause death.

a/(b blank)

TM 9-4935-601-14-7&P

This material is reproduced through the courtesy of Hewlett-Packard Company. Distribution is limited to use with the

PATRIOT missile system.

TECHNICAL MANUAL

No. 9-1430-601-14-7&P )

)

) HEADQUARTERS

DEPARTMENT OF THE ARMY

Washington, D.C.,10 September 1986

Operator, Organizational, and DS/GS Maintenance Manual

(INCLUDING REPAIR PARTS)

FOR

8640B SIGNAL GENERATOR

(Including Option 001)

(PATRIOT AIR DEFENSE GUIDED MISSILE SYSTEM)

This manual applies directly to instruments with serial numbers prefixed 1324A.

With changes described in Section VII, this manual also applies to instruments with serial numbers prefixed 1229A, 1244A, 1245A, 1246A, 1249A, 1251A, 1303A, 1310A, 1313A, 1316A, 1322A, 1323A,

1327A, 1332A, 1333A, 1339A, 1342A, 1345A, 1350A, 1401A, 1404A, 1404A, 1405A, 1406A, 1416A,

1419A, 1423A, 1429A, 1431A, 1435A, 1438A, 1440A, 1442A, 1501A, 1506A, 1513A, 1515A, 1519A,

1520A, 1524A, 1526A, 1530A, 1532A, 1534A, 1535A, 1538A, 1542A, 1543A, 1544A, 1545A, and

1552A.

For additional important information about serial numbers see INSTRUMENTS COVERED BY

MANUAL in Section I.

REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS

You can help improve this manual. If you find any mistakes, or if you find a way to improve the procedures, please let us know. Mail your letter, DA Form 2028 (Recommended Changes to

Publications and Blank Forms), or DA Form 2028-2 direct to: Commander, U.S. Army Missile

Command, ATTN: AMSMILC-ME-PM, Redstone Arsenal, Alabama 35898-5238. A reply will be furnished to you.

Section

TM 9-4935-601-14-7&P

CONTENTS

Page

General

Maintenance Forms and Records ..................................................

0-1

Reporting Equipment Improvement Recommendations

(EIR) .........................................................................................

0-1

Administrative Storage ...................................................................

0-1

Destruction of Army Material to Prevent Enemy

Use ...........................................................................................

0-1

General Information

Introduction ...................................................................................

1-1

Instrument Covered by Manual ......................................................

1-1

General Description .......................................................................

1-2

Performance Characteristics .........................................................

1-2

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 .............................................................................

1-5

Options .........................................................................................

1-6

Accessories Supplied ....................................................................

1-6

Equipment Available .....................................................................

1-6

Warranty .......................................................................................

1-7

Test Equipment Required ..............................................................

1-7

Installation

Introduction ...................................................................................

2-1

Initial Inspection ............................................................................

2-1

Preparation for Use .......................................................................

2-1

Power Requirements ................................................................

2-1

Line Voltage Selection ..............................................................

2-2

Power Cable .............................................................................

2-2

Mating Connectors ....................................................................

2-3

Operating Environment .............................................................

2-3

Bench Operation .......................................................................

2-3

Rack Mounting .........................................................................

2-3

Storage and Shipment ...................................................................

Section

TM 9-4935-601-14-7&P

CONTENTS (Continued)

Page

Environment ..................................................................................

2-3

Packaging ......................................................................................

2-3

Operation

Introduction ....................................................................................

3-1

Panel Features...............................................................................

3-1

Operator's Checks..........................................................................

3-1

Operating Instructions ....................................................................

3-1

Operator's Maintenance .................................................................

3-1

Performance Tests

Introduction ....................................................................................

4-1

Equipment Required.......................................................................

4-1

Test Record ...................................................................................

4-1

Test Procedures .............................................................................

4-1

Frequency Range Test ...................................................................

4-2

Frequency Accuracy and Fine Tune Test ......................................

4-3

Frequency Stability vs Time and Restabilization

Time Test .................................................................................

4-5

Frequency Stability vs Temperature Test ......................................

4-7

Frequency Stability vs Line Voltage Test .......................................

4-8

Frequency Stability vs Load, Level, and

Mode Test ................................................................................

4-9

Harmonics Test ..............................................................................

4-11

Sub-Harmonics and Non-Harmonic Spurious

Test ..........................................................................................

4-13

Single Sideband Phase Noise Test ................................................

4-15

Single Sideband Broadband Noise Floor Test ................................

4-17

Residual AM Test ...........................................................................

4-20

Residual FM Test ...........................................................................

4-21

Output Level Accuracy Test (Abbreviated) .....................................

4-24

Output Level Flatness Test ............................................................

4-29

Output Level Flatness Test ............................................................

4-36

Output Impedance Test (In Band) ..................................................

4-37

Output Impedance Test (Out of Band) ...........................................

4-39

Auxiliary Output Test......................................................................

4-41

Output Leakage Test ......................................................................

4-42

Internal Modulation Oscillator Test ................................................

4-44

Internal Modulation Oscillator Distortion

Test (Option 001) ......................................................................

4-45

AM 3 dB Bandwidth Test ................................................................

4-47

iii

Section

TM 9-4935-601-14-7&P

CONTENTS (Continued)

Page

AM Distortion Test .........................................................................

4-49

AM Sensitivity and Accuracy Test. ...............................................

4-50

Peak Incidental Phase Modulation Test .........................................

4-54

Pulse Modulation Test ...................................................................

4-56

Pulse On/Off Ratio Test ................................................................

4-60

FM 3 dB Bandwidth Test ...............................................................

4-61

FM Distortion Test .........................................................................

4-62

FM Sensitivity and Accuracy Test .................................................

4-64

Incidental AM Test ........................................................................

4-68

Counter External Sensitivity Test ..................................................

4-70

Internal Reference Accuracy Test ..................................................

4-71

Internal Reference Drift Rate (Stability)

Test ..........................................................................................

4-72

Phase Lock Restabilization Time Test ...........................................

4-75

Adjustments

Introduction ...................................................................................

5-1

Safety Considerations ...................................................................

5-1

Test Equipment Required ..............................................................

5-1

Pozidriv Screwdrivers ...............................................................

5-1

Blade Tuning Tools ...................................................................

5-1

Service Aids .............................................................................

5-1

Factory Selected Components ......................................................

5-2

Post-Repair Test and Adjustments ................................................

5-3

Power Supply Adjustments ............................................................

5-8

Fixed-Frequency Modulation Oscillator

Adjustment ................................................................................

5-8

Variable-Frequency Modulation Oscillator

Adjustment (Option 001) ...........................................................

5-9

Meter Adjustments ........................................................................

5-12

RF Detector Offset Adjustment ......................................................

5-12

Output Level Knob Adjustment ......................................................

5-13

Output Level Vernier and Meter Adjustment ...................................

5-14

AM Sensitivity Adjustment .............................................................

5-17

Peak Deviation and Range Switch Adjustment ...............................

5-19

Range Switch Adjustment .............................................................

5-20

VT Pot (A3R1) Adjustment ............................................................

5-21

VT Voltage Adjustment ..................................................................

5-22

RF Filter Adjustment .....................................................................

5-23

Preliminary FM Adjustments .........................................................

5-27

FM Linearity Adjustment ................................................................

Section

TM 9-4935-601-14-7&P

CONTENTS (Continued)

Page

FM Sensitivity Adjustment .............................................................

5-32

Internal Reference Frequency Adjustment......................................

5-34

RF Oscillator End Stop Adjustment ...............................................

5-36

RF Oscillator Output Power Adjustment .........................................

5-38

FM Linearity Adjustment (Alternate) ..............................................

5-40

Replaceable Parts

Introduction ....................................................................................

6-1

Exchange Assemblies ....................................................................

6-1

Abbreviations .................................................................................

6-1

Replaceable Parts List....................................................................

6-1

Ordering Information ......................................................................

6-1

Spare Parts Kit ...............................................................................

6-1

Illustrated Parts Breakdowns .........................................................

6-2

Manual Changes

Introduction ....................................................................................

7-1

Manual Changes ............................................................................

7-1

Manual Change Instructions ..........................................................

7-4

Instrument Improvement Modifications ..........................................

7-78

Improved FM Metering Accuracy (Serial

Prefix 1229A) .......................................................................

7-78

Elimination of Frequency Shift in Expand

X100 Mode (Serial Prefix 1229A) .........................................

7-78

A8A2 Counter/Lock Board Assembly

Improvements (Serial Prefix 1229A) ....................................

7-78

Improved Audio Output Level Accuracy

(Serial Prefix 1229A) ............................................................

7-80

A26A1 Power Amplifier and AGC Detector

Assembly Improvement (Serial Prefix 1229A).......................

7-80

Reduction of RFI Leakage from Front Panel

(Serial Prefix 1244A and Below) ..........................................

7-80

A26A4 AGC Amplifier Assembly Improvement

(Serial Prefix 1245A and Below) ..........................................

7-81

Reduction of RFI Leakage from RF Oscillator

(Serial Prefix 1246A and Below) ..........................................

7-81

Replacement A7 FM Shaping Assembly (Serial

Prefix 1246A and Below) ......................................................

7-81

Replacement A9 Peak Deviation and Range

Switch Assembly (Serial Prefix 1246A and

Below) .................................................................................

Section

TM 9-4935-601-14-7&P

CONTENTS (Continued)

Page

A10A1 RF Filter Assembly Switch Improvement

(Serial Prefix 1246A and Below) ...............................................

7-83

A8A1 RF Scaler Assembly Improvement (Serial

Prefix 1249A) ...........................................................................

7-83

A5 FM Amplifier Assembly Improvement (Serial

Prefix 125lA and Below) ...........................................................

7-83

A8A2 Counter/Lock Board Assembly Improvement

(Serial Prefix 1251A and Below) ...............................................

7-83

Front Panel Meter M1 Replacement (Serial

Prefix 125lA and Below) ...........................................................

7-83

A26 AM/AGC and RF Amplifier Assembly

Improvement ............................................................................

7-84

A26A4 AGC Amplifier Assembly Improvement

(Serial Prefix 1310A and Below) ...............................................

7-84

A10A2 RF Divider Assembly Improvement (Serial

Prefix 1313A and Below) ..........................................................

7-85

Power Supply Improvement (Serial Prefix 1313A and Below) ...............................................................................

7-86

A10A2 RF Divider Assembly Improvement (Serial

Numbers 1316A00464 and Below) ............................................

7-86

Improved Audio Output Level Flatness (Serial

Prefixes 1244A through 1316A) ................................................

7-86

A8A4 Counter Display Assembly Improvement

(Serial Prefixes 1323A and Below) ...........................................

7-86

Improved FM Bandwidth on 5kHz Deviation Range

(Serial Number Prefixes 1323A and 1327A................................

7-86

Improved Noise Performance (Serial Prefixes

1327A and Below) ....................................................................

7-86

A10A2 RF Divider Assembly Improvement (Serial

Number Prefixes 1333A and Below) .........................................

7-86

A18, A20, and A22 Power Supply Regulator

Improvements (Serial Number Prefixes 133A and Below). .............................................................................

7-87

Time Base Vernier and Pot Replacement (Serial

Prefix 1333A and Below) ..........................................................

7-87

All Variable Frequency Modulation Oscillator

Improvements (Serial Number Prefixes

1339A and Below) ....................................................................

7-87

A12 Rectifier Assembly Input Crowbar Failures

(Serial Number Prefixes 1330A and Below) ..............................

7-87

Reliability Improvements in AM and Pulse

Circuits (Serial Number Prefixes 1345A and Below) ................................................................................

Section

TM 9-4935-601-14-7&P

CONTENTS (Continued)

Page

All Variable Frequency Modulation Oscillator

(Option 001) Improvement (Serial Number

Prefixes 1350A and Below) .......................................................

7-88

Improvement in Lock Acquisition Capability

(Serial Number Prefixes 1350A and Below) ...............................

7-88

+44.6V Regulator Improvement (Serial Number

Prefixes 1405A and Below) .......................................................

7-88

Line Switch Modification (Serial Number

Prefixes 1406A and Below) .......................................................

7-88

Reduction in Popcorn Noise on Power Supplies

(Serial Number Prefixes 1406A and Below) ..............................

7-89

Recommended Fuse Replacement for 110/240V

Operation (Serial Number Prefixes 1423A and Below) ...............................................................................

7-89

"REDUCE PEAK POWER" Lamp Drive Modification

(Serial Number Prefix 1526A and Below)...................................

7-89

Service

Introduction ...................................................................................

8-1

Principles of Operation ..................................................................

8-1

Troubleshooting ............................................................................

8-1

Recommended Test Equipment .....................................................

8-1

Service Aids ..................................................................................

8-1

Repair ...........................................................................................

8-3

Factory Selected Components ..................................................

8-3

Etched Circuits .........................................................................

8-3

Etched Conductor Repair ..........................................................

8-3

Component Replacement .........................................................

8-3

Illustrated Parts Breakdowns .....................................................

8-5

Basic Circuit Theory ......................................................................

8-5

Binary Circuits and Symbols .....................................................

8-5

Binary Registers .......................................................................

8-8

Binary Latch ..............................................................................

8-8

Binary Shift Register .................................................................

8-8

Decade Counters and Symbols .................................................

8-9

Linear Integrated Circuits ..........................................................

8-11

vii

Table

Figure

TM 9-4935-601-14-7&P

TABLES

Page

Specifications ................................................................................

1-8

Recommended Test Equipment ....................................................

1-13

Recommended Test Accessories ..................................................

1-20

Performance Test Record .............................................................

4-77

Recommended Test Abridgements ...............................................

4-85

Factory Selected Components ......................................................

5-2

Post-Repair Test and Adjustments ................................................

5-4

RF Filter Check .............................................................................

5-26

Part Numbers for Exchange Assemblies .......................................

6-2

Reference Designations and Abbreviations ...................................

6-3

Replaceable Parts .........................................................................

6-5

Code List of Manufacturers ...........................................................

6-42

Manual Changes by Serial Number ...............................................

7-1

Summary of Changes by Component ............................................

7-2

Etched Circuit Soldering Equipment ..............................................

8-4

Logic Levels ..................................................................................

8-6

Assembly Information Index ..........................................................

8-14

Schematic Diagram Notes .............................................................

8-15

Meter Drive Amplifier Data ............................................................

8-52

Total Count of Time Base Reference Counters U13,

U14, and U15 ...........................................................................

8-56

Count Modes of Counters A8A3U13 and U14 ................................

8-56

Count Modes of Counter A8A3U15 ................................................

8-56

Data Inputs of Decimal Point Shift Register ...................................

8-56

ILLUSTRATIONS

Page

HP Model 8640B Signal Generator (Option 001) and

Accessories Supplied ................................................................

1-0

Measured Single Sideband Noise vs Offset from Carrier ................

1-2

Specified Signal-to-Phase Noise Ratio ..........................................

1-3

AM Distortion vs AM Rate .............................................................

1-4

Pulsed RF .....................................................................................

1-4

FM Distortion vs FM Rate ..............................................................

1-5

520 MHz Notch Filter ....................................................................

1-21

FM Linearity Circuit .......................................................................

1-22

Line Selector .................................................................................

2-1

Power Cables Available ................................................................

2-2

Preparation for Rack Mounting ......................................................

2-4

viii

Figure

TM 9-4935-601-14-7&P

ILLUSTRATIONS (Continued)

Page

Lamp Replacement .......................................................................

3-1

Front Panel Controls, Indicators, and Connectors ..........................

3-2

Rear Panel Controls, and Connectors ............................................

3-6

Operator's Checks .........................................................................

3-7

Setting the Frequency and Amplitude Controls ..............................

3-12

Setting the Modulation Controls .....................................................

3-15

Frequency Stability vs Time and Restabilization Time

Test Setup .................................................................................

4-5

Frequency Stability vs Temperature Test Setup ............................

4-7

Frequency Stability vs Line Voltage Test Setup .............................

4-8

Frequency Stability vs Load, Level, and Mode Test

Setup.........................................................................................

4-10

Sub-flarrmonics and Non-Harmonic Spurious Test Setup ..............

4-14

Single Sideband Phase Noise Test Setup ......................................

4-15

Single Sideband Broadband Noise Floor Test Setup .....................

4-18

Residual AM Test Setup ................................................................

4-20

Output Level Accuracy Test Setup (Abbreviated) ..........................

4-25

Output Level Accuracy Test Setup (Complete) ..............................

4-31

Output Level Flatness Test Setup .................................................

4-36

Output Impedance Test Setup (In Band) .......................................

4-38

Output Impedance Test Setup (Out of Band) .................................

4-40

Output Leakage Test Setup ...........................................................

4-42

Internal Modulation Oscillator Test Setup ......................................

4-44

Internal Modulation Oscillator Distortion Test

Setup. ......................................................................................

4-46

AM 3 dB Bandwidth Test Setup .....................................................

4-47

AM Distortion Test Setup ...............................................................

4-49

AM Sensitivity and Accuracy Test Setup .......................................

4-51

Peak Incidental Phase Modulation Test Setup ...............................

4-54

Pulse Modulation Test Setup .........................................................

4-57

Pulse Measurements .....................................................................

4-58

FM 3 dB Bandwidth Test Setup .....................................................

4-61

FM Distortion Test Setup ...............................................................

4-63

FM Sensitivity and Accuracy Test Setup .......................................

4-65

Incidental AM Test Setup ..............................................................

4-68

Counter External Sensitivity Test Setup ........................................

4-70

Internal Reference Accuracy Test Setup .......................................

4-71

Internal Reference Drift Rate (Stability) Test Setup ........................

4-73

Output Level Vernier and Meter Adjustment Test Setup .................

5-15

AM Sensitivity Adjustment Test Setup ...........................................

5-17

VT Pot Adjustment ........................................................................

5-21

Filter Terminology ..........................................................................

5-23

RF Filter Adjustment Test Setup ...................................................

Figure

TM 9-4935-601-14-7&P

ILLUSTRATIONS (Continued)

Page

256-512 MHz High Band Capacitor Adjustment

Orientation.................................................................................

5-27

DM Linearity Adjustment Test Setup .............................................

5-30

FM Linearity Display ......................................................................

5-32

FM Sensitivity Adjustment Test Setup ...........................................

5-33

Internal Reference Frequency Adjustment Test Setup ....................

5-35

Location of RF Oscillator Stop Adjustments Shown in Maximum ccw Position. Top View with Instrument

Upside Down ............................................................................

5-37

RF Oscillator Output Power Adjustment Test Setup ......................

5-38

FM Linearity Adjustment (Alternate) Test Setup ............................

5-40

Cabinet Parts .................................................................................

6-40

Type N Connector .........................................................................

6-41

A8A2 Counter/Lock Board Assembly Backdating

(Change B) ................................................................................

7-12

A3A4 Connector Board Assembly Backdating (Change C) ............

7-13

A26A1 Power Amplifier and AGC Detector Assembly

Backdating (Change D) .............................................................

7-14

A26A2U1 Backdating (Change E) ..................................................

7-17

A8A1 RF Scaler Assembly Backdating (Change E) .......................

7-18

A12 Rectifier Assembly Backdating (Change F) .............................

7-19

A8A1 Scaler Assembly Backdating (Change J) ..............................

7-22

A8A4 Counter Display Assembly Modification ...............................

7-79

A7 FM Shaping Assembly Modification ..........................................

7-82

A9 Peak Deviation and Range Switch Modification .......................

7-23

AlOA2 RF Divider Assembly Modification ......................................

7-26

Signal Generator with Circuit Boards on Extenders .......................

8-2

Examples of Diode and Transistor Marking Methods .....................

8-4

Binary Symbols .............................................................................

8-6

Triggered Flip-Flop.........................................................................

8-7

D Flip-Flop ....................................................................................

8-7

Schmitt Trigger ..............................................................................

8-7

JIK Flip-Flop...................................................................................

8-8

Multiple Input J/K Flip-Flop ............................................................

8-8

Binary Latch ..................................................................................

8-9

Binary Shift Register .....................................................................

8-9

Basic Decade Counter (Scaler) .....................................................

8-9

Programmable Counter .................................................................

8-10

Programmable Up/Down Counter ..................................................

8-12

Operational Amplifier ....................................................................

8-13

Comparator ...................................................................................

8-14

Overall Block Diagram ..................................................................

Figure

TM 9-4935-601-14-7&P

ILLUSTRATIONS (Continued)

Page

FM Circuits and RF Oscillator Block Diagram ................................

8-21

AM/AGC Circuits and Output Amplifier Block Diagram ..................

8-23

Counter/Lock Circuits Block Diagram ............................................

8-25

P/O A3A4 Connector Board Assembly Component

Location.....................................................................................

8-27

RF Oscillator Simplified Diagram ..................................................

8-27

P/O A3A4 Connector Board Assembly Component

Locations ...................................................................................

8-28

P/O A9 Peak Deviation and Range Switch Assembly

Component Locations ...............................................................

8-28

A5 FM Amplifier Assembly Component Locations .........................

8-29

FM Amplifiers Schematic Diagram ................................................

8-29

P/O A7 FM Shaping Assembly Component Locations ...................

8-31

FM Shaping Circuits and Phase Lock Loop Filter

Schematic Diagram ..................................................................

8-31

P/O A6 Annunciator Assembly Component Locations ....................

8-32

P/O A9 Peak Deviation and Range Switch Assembly

Component Locations ...............................................................

8-32

P/O A7 FM Shaping Assembly Component Locations ...................

8-33

Over-Deviation Detector and Meter Control Circuits

Schematic Diagram ..................................................................

8-33

All Fixed-Frequency Modulation Oscillator Assembly

Component Locations ...............................................................

8-35

Fixed-Frequency Modulation Oscillator Schematic

Diagram ...................................................................................

8-35

All Variable-Frequency Modulation Oscillator Assembly

(Option 001) Component Locations ..........................................

8-37

Variable-Frequency Modulation Oscillator (Option 001)

Schematic Diagram ...................................................................

8-37

A10A1 RF Filter Assembly Component Locations .........................

8-38

RF Filters Schematic Diagram ......................................................

8-39

A10A2 RF Divider Assembly Component Locations ......................

8-41

RF Dividers Schematic Diagram ...................................................

8-41

A26A3 Modulator Assembly Component Locations ........................

8-43

A26A4 AGC Amplifier Assembly Component Locations .................

8-43

AGC Amplifiers and Amplitude Modulator Schematic

Diagram ........................................................................................

8-43

A26A1 Power Amplifier and AGC Detector Assembly

Component Locations ....................................................................

8-45

P/O A26A2 AM Offset and Pulse Switching Assembly

Component Locations ....................................................................

8-45

RF Amplifier, Pulse Switching, and Step Attenuator

Schematic Diagram .......................................................................

Figure

TM 9-4935-601-14-7&P

ILLUSTRATIONS (Continued)

Page

P/O A26A2 AM Offset and Pulse Switching Assembly

Component Locations ...............................................................

8-47

AM Preamplifier Schematic Diagram .............................................

8-47

AM Interconnections and RF ON/OFF Switch Schematic

Diagram ....................................................................................

8-49

AlA1 RF Vernier Assembly Component Locations .........................

8-51

RF Vernier Schematic Diagram .....................................................

8-51

A2 Meter Switch/Detector Assembly Component

Location.....................................................................................

8-52

A4 Meter/Annunciator Drive Assembly ..........................................

8-53

P/O A6 Annunciator Assembly Component Location .....................

8-53

Meter Circuits Schematic Diagram ................................................

8-53

A8A1 RF Scaler Assembly Component Locations .........................

8-55

P/O A8A3 Time Base Assembly Component Locations ..................

8-55

Counter RF Scaler Schematic Diagram .........................................

8-55

P/O A8A3 Time Base Assembly Component Locations .................

8-57

Counter Time Base Schematic Diagram ........................................

8-57

A8A4 Counter Display Assembly Component Locations

(P/O A8) ...................................................................................

8-59

P/O A8A2 Counter/Lock Board Assembly Component

Locations. ................................................................................

8-59

Up/Down Counter and Display Schematic Diagram .......................

8-59

P/O A8A2 Counter/Lock Board Assembly Component

Locations. ................................................................................

8-61

Counter Phase Lock Circuits Schematic Diagram ..........................

8-61

Current Foldback............................................................................

8-62

A12 Rectifier Assembly Component Locations ..............................

8-62

A20 +5.2V and +44.6V Regulator Assembly Component

Locations ..................................................................................

8-63

A22 +20V and -20V Regulator Assembly Component

Locations. ................................................................................

8-63

Power Supply Circuits Schematic Diagram ....................................

8-63

A18 -5.2V Regulator and Fan Driver Assembly Component

Locations ..................................................................................

8-65

A18 -5.2V Regulator and Fan Circuits Schematic

Diagram ...................................................................................

8-65

A17 Power Supply Mother Board Assembly Component

Locations ...................................................................................

8-67

Power Supply Mother Board Schematic Diagram ..........................

8-67

A13 Modulation/Metering Mother Board Assembly

Component Locations ...............................................................

8-68

xii

Figure

8-83

TM 9-4935-601-14-7&P

ILLUSTRATIONS (Continued)

Page

Modulation/Metering Mother Board Schematic Diagram .................

8-69

A1 Output Level Assembly Illustrated Parts Breakdown..................

8-71

A8 Counter/Lock Assembly Illustrated Parts Breakdown .................

8-73

A9 Peak Deviation and Range Switch Assembly

Illustrated Parts Breakdown ......................................................

8-75

A11 Variable-Frequency Modulation Oscillator (Option

991) Illustrated Parts Breakdown ..............................................

8-75

A10 Divider/Filter Assembly Illustrated Parts

Breakdown ...............................................................................

8-77

A26 AM/AGC and RF Amplifier Illustrated Parts

Breakdown ...............................................................................

8-79

Top Internal Views (Option 001 shown) .........................................

8-81

Rear Panel View ...........................................................................

8-83

Bottom Internal Views (Option 001 shown) ....................................

8-83

Number

SERVICE SHEETS

Page

Overall Block Diagram ..................................................................

8-18

FM Circuits and RF Oscillator Troubleshooting ..............................

8-20

AM/AGC Circuits and Output Amplifier Troubleshooting.................

8-22

Counter/Lock Circuits Troubleshooting ..........................................

8-24

RF Oscillator (A3) ..........................................................................

8-26

FM Amplifiers (A3, A5, A9, A13) ...................................................

8-28

FM Shaping Circuits and Phase Lock Loop Filter

(A7, A9) ....................................................................................

8-30

Over-Deviation Detector and Meter Control Circuits

(A6, A7, A9)...............................................................................

8-32

Fixed-Frequency Modulation Oscillator (All, A13) ..........................

8-34

Variable-Frequency Modulation Oscillator for Option

001 (A11, A13) .........................................................................

8-36

RF Filters (A10Al) .........................................................................

8-38

RF Dividers (A10A2) .....................................................................

8-40

AGC Amplifiers and Amplitude Modulator (A26A3,

A26A4) ......................................................................................

8-42

RF Amplifier, Pulse Switching, and Step Attenuator

(A1, A26A1, A26A2) .................................................................

8-44

AM Preamplifier (A13, A26A2) ......................................................

8-46

AM Interconnections and RF ON/OFF Switch (A9, A26) ................

8-48

RF Vernier (A1A1, A26) ................................................................

8-50

xiii

Number

TM 9-4935-601-14-7&P

SERVICE SHEETS

Page

Meter Circuits (A2, A4, A6) ............................................................

8-52

Counter RF Scaler (A8A1, A8A3) ..................................................

8-54

Counter Time Base (A8A3, A9) .....................................................

8-56

Up/Down Counter and 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 Assembly Removal and Disassembly ........................................

8-70

A8 Assembly Removal and Disassembly .......................................

8-72

A9 and All Assemblies Removal and Disassembly ........................

8-74

A10 Assembly Removal and Disassembly .....................................

8-76

A26 Assembly Removal and Disassembly .....................................

8-78

General Removal Procedures and Top Internal Views....................

8-80

Rear Panel and Bottom Internal Views ..........................................

8-83

xiv

Model 8640B

WARNINGS

SAFETY

To avoid the possibility of injury or death, the following precautions must be followed before the instrument is switched on: a. If this instrument is to be energized via an autotransformer for voltage reduction, make sure that the common terminal is connected to the earth grounded pole of the power source.

b. The power cable plug shall only be 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 cord is wired correctly (see Service 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.

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.

TM 9-4935-601-14-7&P

CAUTIONS

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 LINE VOLTAGE 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 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 equipment, 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 voltage or >+15 dBm to COUNTER

INPUT.

SEMI-RIGID COAX

While working with and around the semi-rigid coaxial cables in the generator, do not bend the cables more than necessary. Do not torque the RF connectors to more than 5 inch-pounds.

xv/(xvi blank)

TM 9-1430-601-14-7&P

SECTION 0

GENERAL

0-1 MAINTENANCE FORMS AND RECORDS

Department of the Army forms and procedures used for equipment maintenance will be those prescribed by TM 38-750,

The Army Maintenance Management System (TAMMS).

0-2 REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIR)

If your PATRIOT system needs improvement, let us know. Send us an EIR. You, the user, are the only one who can tell us what you do not like about your equipment. Let us know why you do not like the design. EIRs will be prepared using

SF 368, Quality Deficiency Report (QDR). Mail the QDRs to Commander, U.S. Army Missile Command, ATTN:

AMSMI-LC-ME-PMH, Redstone Arsenal, AL 35898-5238. A reply will be furnished to you.

0-3 ADMINISTRATIVE STORAGE

To prepare this unit for placement into and removal from administrative storage, refer to section 3, chapter 4, of AR 750-

1, Maintenance Equipment and Supplies. Temporary storage should be accomplished in accordance with TB 750-25-1, section 2, Maintenance of Supplies and Equipment.

0-4 DESTRUCTION OF ARMY MATERIAL TO PREVENT ENEMY USE

For procedures for destruction of Army material to prevent enemy use, see section XI of TM 9-4935-393-14-1.

0-1/(0-2 blank)

Model 5640B TM 9-4935-601-14-7&P

Figure 1-1. HP Model 8640B Signal Generator (Option 001) and Accessories Supplied

1-0

Model 8640B TM 9-4935-601-14-7&P

SECTION I

1-1. INTRODUCTION

GENERAL INFORMATION

Hewlett-Packard Sales and Service Office; the part number is listed on the title page of this manual and on the rear cover of the supplement.

1-2. This manual contains the operating and service information for the Hewlett-Packard Model 8640B Signal

Generator. The Signal Generator (with variable

modulation oscillator Option 001) is shown in Figure 1-1

with all of its externally supplied accessories.

1-5. Also listed on the title page of this manual is a

"Microfiche" part number. This number can be used to

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 information: order 4 x 6 inch microfilm transparencies of the manual.

Each microfiche contains up to 60 photo duplicates of the manual's pages. The microfiche package also includes the latest Manual Changes supplement as well as all pertinent Service Notes.

1-6. Instrument specifications are listed in Table 1-1.

These specifications are the performance standards or

Section II, Installation: provides information about

initial inspection, preparation for use, and storage and shipment.

limits against which the instrument can be tested.

Paragraph 1-17 lists some supplemental performance

characteristics. Supplemental characteristics are not specifications but are typical characteristics included as additional information for the user.

Section III, Operation: provides information about

panel features, and provides operating checks, instructions, and maintenance information.

1-7. INSTRUMENTS COVERED BY MANUAL

Section IV, Performance Tests: provides the

information required to verify that the instrument is

performing as specified in Table 1-1.

Section V, Adjustments: provides the information

required to properly adjust and align the instrument.

1-8. This instrument has a two-part serial number. The first four digits and the letter comprise the serial number prefix. 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 same serial number prefixes as listed under SERIAL

NUMBERS on the title page.

Section VI, Replaceable Parts: provides ordering

information for all replaceable parts and assemblies.

Section VII, Manual Changes: this section provides

manual change information necessary to document all prefixes listed on the title page. Also in this section is information covering suggested instrument modifications.

1-9. An instrument manufactured after the printing of this manual may have a serial prefix that is not listed on the title page. This unlisted serial prefix indicates that the instrument is different from those documented in this manual. The manual for this instrument is supplied with a yellow Manual Changes supplement that contains

"change information" that documents the differences.

Section VII, Service: provides the information required

to repair the instrument.

1-4. Packaged with this manual is an Operating

Information Supplement. This is simply a copy of the first three sections of this manual. This supplement should stay with the instrument for use by the operator.

Additional copies can be ordered through your nearest

1-10. In addition to change information, the supplement may contain information for correcting errors in the manual. To keep this manual as current and accurate as possible, Hewlett-Packard recommends that you periodically request the latest Manual Changes supplement. The supplement for this manual is keyed to this

1-1

Model 8640B

manual's print date and part number, both of which appear on the title page. Complimentary copies of the supplement are available from Hewlett-Packard.

1-11. For information concerning a serial number prefix not listed on the title page or in the Manual Changes supplement, contact your nearest Hewlett Packard office.

1-12. GENERAL DESCRIPTION

1-13. The Model 8640B 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. This broad coverage, together with calibrated output and modulation, provides for complete RF and IF performance tests on virtually any type of HF, VHF, or

UHF receiver.

1-14. This solid state generator has an output level range of +19 to -145 dBm (2 V to 0.013 MV) and is calibrated and metered. The output is leveled to within

+0.5 dB across the full frequency range of the instrument.

1-15. 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.

1-16. Other significant features are extremely low noise, built-in phase lock and counter, and front panel controls designed for operating convenience and flexibility.

1-17. PERFORMANCE CHARACTERISTICS

1-18. Spectral Purity

1-19. The basic frequency source of the 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 are virtually eliminated. A band over-range of 7% to 10% is also

1-2

TM 9-4935-601-14-7&P

provided for convenience when operating near the nominal band edges.

1-20. Frequency tuning within the selected band is accomplished with approximately 8 turns of the

FREQUENCY TUNE control (see Figure 3-2) for fast

selection of the desired output frequency. A mechanical

FINE TUNE control has a tuning range of 200 ppm for precision frequency setting.

1-21. 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 bands for a fixed position on the frequency tune control.

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. Noise performance of the generator is state of the art for a solid state generator. 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

Model 8640B TM 9-4935-601-14-7&P

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.

1-23. Figure 1-3 gives a plot of the guaranteed SSB

noise performance 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 550 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 140 dB/Hz. This exceptional noise performance is also preserved during FM* and in the phase lock mode.

Figure 1-3. Specified Signal-to-Phase Noise Ratio at 20 klHz Offset us Carrier Frequency (MHz).

(Stated in a 1 Hz Bandwidth.) For lower frequencies phase-noise decreases approximately 6 dB per frequency division downl to the broadband noise floor.

1-24. Frequency Counter 1-25. The Signal Generator has a built-in 550 MHz frequency counter and phase lock synchronizer. The 6-digit LED display gives a normal resolution of 10 kHz at 500 MHz and 10 Hz at

500 kllz. The resolution can be increased using the X10 or X100 EXPAND buttons near the display. In the X100

1-3

EXPAND mode, the resolution is 100 Hz at 500 MHz and 0.1 Hz at 500 kHz.

1-26. This resolution, combined with the high stability of the generator, provides precision frequency selection and meaningful measurements on high performance receiver systems. When selecting the external doubler band, the counter displays the doubled output frequency directly.

1-27. When using the expand modes, it is possible for significant digits or the decimal point to be shifted off the display. When this occurs, an OVERFLOW light reminds the operator that the display is not showing the complete output frequency.

1-28. 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 502. Using the EXPAND buttons, it is possible to achieve a resolution of 1 Hz in the 0-10 vMHz

EXTERNAL count mode or 100 Hz in the 0-550 MHz mode.

1-29. Phase-Lock Mode

1-30. 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 and the spectral purity and FM capability (down to

50 Hz rates) 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 together for various two-tone measurements.

1-31. 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 exampled by tuning 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:

1-32. Lock can be achieve in the normal mode of the counter or in the X10 EXPAND mode if the OVERFLOW light is not on. It is not possible to lock in the X100

EXPAND mode or when counting external inputs.

Maximum resolution in the locked mode is I kHz at 500

MHz, increasing to 1 Hz at 500 kllz.

Model 8640B

1-33. 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 digits to the right of the display). This gives continuous coverage of all output frequencies even in the phase lock mode. An

UNCAL light near the vernier will indicate when this mode has been selected since the counter display is incorrect.

1-34. When phase locked, FM capability is preserved down to modulation rates of <50 Hz. The narrow bandwidth of the phase lock loop (<5 Hz) allows FM up to 250 kHz rates and assures no degradation in noise from the unlocked mode. The generator's residual FM is not changed by phase lock.

1-35. Amplitude Modulation 1-36. AM is variable from

0 to 100% with the bandwidth, accuracy, and low incidental FM required for the most stringent AM applications. The front panel meter gives a direct readout of AM% in either the internal or external mode and autoranges the 0 -100% scale at 0 30% for improved settability at low modulation depth.

1-37. AM up to bandwidths of 60 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 50 kHz for an output frequency of 200

MHz.

TM 9-.4935-601-14-7&P

1-38. Pulse Modulation

1-39. 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 us can be applied to modulate the RF carrier.

Rise and fall times vary with output frequency down to <

1 us from 8 to 512 MHz.

1-40. Pulse inputs turn the RF on. Hence with no pulse input the RF will read approximately zero on the built-in level meter. For pulse inputs within the specified range, the RF output 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.

Figure 1-5. Pulsed RF 20 MHz Carrier Frequency

1-41. Frequency Modulation

1-42. FM is calibrated, metered and constant with frequency and band changes. Peak deviations to at least 0.5% of carrier frequency are available (i.e., 1% of the minimum frequency in each octave band). On the

256 512 MHz band, for example, 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.

Figure 1-4. AM distortion us AM rate measured at

200 MHz and +13 dBm, but applies to all bands.

(Supplemental information only.)

1-4

Model 8640B

1-43. 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 CW to 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 from

50 Hz to 250 kHz with accurate narrowband FM and the carrier drift stability of a crystal oscillator. Using the unlocked mode, it is possible to modulate from dc to 250 kHz with a carrier drift stability of <10 ppm/10 min.

Figure 1-6. FM distortion vs FM rate measured in the 8-16MHz band, but applies to all bands

(supplemental information only).

1-44. Standard and Optional Audio Oscillators

1-45. 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 600Q. Total harmonic distortion is typically

<0.25%.

1-46. 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 provides a wide range of standard modulation frequencies and can be used for receiver audio bandwidth testing as well.

Output from this modulation source is available separately at the front panel and can be varied in level from 3 V to 20 mV into 600Q. This audio oscillator,

Option 001, extends the usable CW range of the generator down to 20 Hz.

TM 9-4935-601-14-7&P

1-47. Multi-Function Meter and Annunciators

1-48. The front panel on the Signal Generator monitors the RF output level in dBm and volts, the AM modulation percentage, and the FM peak deviation in kHz or MHz. The accuracy of this meter is usually better than +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.

1-49. 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 how to return the instrument to proper operation.

1-50. For example, the REDUCE PEAK POWER annunciator lights whenever the combined settings of

RF output level and AM modulation exceed the maximum specified output level of +19 dBm. Hence for

100% AM, the REDUCE PEAK POWER light will stay on until the RF level is reduced to +13 dBm.

1-51. 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 the and FM meter reads zero.

1-52. 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.

1-53. Output Level 1-54. The wide output range of the generator is achieved with a 10 dB step attenuator and an 18 dB concentric vernier. Output levels can be read directly on the attenuator dial or (for greater accuracy) on the autoranging meter. The meter

1-5

Model 8640B

scales are automatically selected to give the maximum indicator resolution for any output level.

1-55. The maximum output level of +19 dBm permits high level tests on receiver IF's, amplifiers, and mixers without additional power 'amplification. At the same time, extremely low leakage ensures receiver sensitivity measurements down to levels of 0.03 uV in a shielded system.

1-56. For improved accuracy at low output levels, the meter, in conjunction with the attenuator, is factorycalibrated against a precision standard to remove much of the error that is accumulated from the attenuator 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.

1-57. OPTIONS

1-58. 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.

1-59. Option 002. Option 002 (not covered in this manual) provides an internal, active frequency doubler that extends the frequency range of the generator to

1024 MHz (to 1100 MHz with overrange).

1-60. Option 003. Option 003 (not covered in this manual) provides reverse power protection to the generator's output attenuator and amplifier. It is particularly useful when using the generator to test transceivers.

1-61. Option 004. Option 004 (not covered in this manual) provides a demodulated output and modified

AM circuitry that can be used to set very accurate AM depths. It also provides a 1 dB output step attenuator in addition to the standard 10 dB output step attenuator.

These features allow the generator to be used to test

VOR, ILS, and VHF communications receivers.

1-62. ACCESSORIES SUPPLIED

1-63. The Model 8640B is supplied with the following

accessories (they are shown in Figure 1-1)

Line Power Cable (HP 8120-1378)

2 Amp Fuse (HP 2110-0002)

1 Amp Fuse (HP 2110-0001)

1-6

TM 9-4935-601-14-7&P

1-64. 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 08640-00027)

Spare fuses for power supply circuit boards

Spare power supply regulator integrated circuit

30-Pin Extender Board (HP 08640-60036)

1-65. EQUIPMENT AVAILABLE

1-66. A Rack Mounting Kit is available to install the instrument in a 19-inch rack. Rack Mounting Kits may be obtained through your nearest HIewlett-Packard

Office by ordering HP Part Number 5060-8740.

1-67. Termination. The HP Model 11507A

Termination 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.

1-68. 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.

1-69. 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). Conversion loss in the doubler is typically <13 dB.

1-70. Mixer. The HP Model 10514A Double Balanced

Mixer can be used at the generator's output as a nanosecond pulse modulator or as a balanced mixer.

1-71. Protective Cover. The HP 5060-8767 Control

Panel Cover protects the panel from dust and impact damage.

TM 9-4935-601-14-7&P

Model 8640B

1-72. WARRANTY

1-73. The Model 8640B is warranted and certified as indicated on the inner front cover of this manual. For further information, contact the nearest Hewlett-Packard

Sales and Service Office; addresses are provided at the back of this manual.

1-74. TEST EQUIPMENT REQUIRED

1-75. Tables 1-2 and 1-3 list the test equipment and

accessories required to check, adjust and repair the

Model 8640B. If substitute equipment is used, it must meet the listed critical specifications.

NOTE

The safety classification of this instrument is Safety Class I. It has been designed and tested according to IEC Publication 348 Safety Requirements for Electronic Measuring Apparatus. The instruction manual contains information, warnings, and cautions which must be followed by the user to ensure safe operation and to retain the instrument in safe condition.

1-7

Model 8640B

TM 9-4935-601-14-7&P

Table 1-1. Specifications (1 of 5)

(All specifications apply over the nominal Frequency Bands and over the top 10 dB of the output level vernier range unless otherwise specified.)

FREQUENCY CHARACTERISTICS

Range: 500 kHz to 512 MHz in 10 Octave Bands (to

1024 MHz with External Frequency Doubler).

Bands and Band Overlap: Bands extend 10% below and 7% above the nominal Frequency Bands shown below.

Frequency Bands (MHz)

0.5 - 1

1 - 2

2 - 4

4- 8

8- 16

16- 32

32 - 64

64 - 128

128 - 256

256 - 512

External Doubler Band

512 - 1024

Internal Counter Resolution:

Frequency Bands

(MHz)

Normal

Mode

0.5-1

1 -16

16 - 128

128 -1024

10 Hz

100 Hz

1 kHz

10 kHz

Frequency Range (MHz)

(with overlap)

0.45 - 1.07

0.9 - 2.1

1.8 - 4.2

3.6 - 8.5

7.2 - 17.1

14.4 -34.3

28.8 - 68.7

57.5 - 137.5

115 - 275

230 - 550

460 - 1100

Expand

X10

1 Hz

10 Hz

100 Hz

1 kHz

Expand

X100

0.1 Hz

1 Hz

10 Hz

100 Hz

Accuracy: 6-digit LED display with X10 and X100 expand; accuracy depends on internal or external reference used.

Total Counter

Count = Resolution +

Accuracy (±1 count)

Reference

Error

(INT or EXT)

Internal Reference Error <±2 ppm

(when calibrated at 25°C every 3 months and operated between 15°C and 35°C)

Fine Tuning:

Unlocked: >200 ppm total range.

Locked mode: >±20 ppm by varying internal time base vernier.

Stability:

Time

(after 2-hour warm-up)

Temperature

Line Voltage

(+5% to -10% line voltage change)

Load

(with any passive load change)

Level Change

(10 dB on output level vernier)

Mode Change

(CW to FM)

Normal

<10 ppm/10min

<50 ppm/°C

<1 ppm

<1% of selected peak deviation or

<200 Hz whichever is greater

Locked

<0.05 ppm/hr

<2 ppm total

(room ambient

15 to 350C)

<0.1 ppm

None measurable

In the External Doubler Band. the 8640B counter displays the actual doubled output frequency. and the FM meter indicates the proper peak deviation.

When phase locked, Counter Resolution error is eliminated.

These specifications are given for the 8640B internal reference. When using an external reference, drift in the locked mode will depend on the external reference characteristics.

Phase lock may break due to temperature change (i.e., during warm-up). Simply relock at desired frequency.

This specification is for short term, transient line changes.

1-8

Model 8640B

TM 9-4935-601-14-7&P

Restabilization Time:

Table 1-1. Specifications (2 of 5)

FREQUENCY CHARACTERISTICS (Cont'd)

After frequency change

After band change

After 1 min in RF

OFF Mode

Normal

<15 min

None

<10 min

Locked

<1 min after relocking to be within

0.1 ppm of steady-state frequency

SPECTRAL PURITY

Harmonics: (at 1 volt, +13 dBm, output range and below)

>35 dB below fundamental of 0.5 to 128 MHz.

>30 dB below fundamental of 128 to 512 MHz.

Subharmonics and Nonharmonic Spurious:

(excluding 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 at maximum vernier greater than 500 kHz offset from carrier. (See

Figures 1-2 and 1-3.) 0.5 to 512 MHz: >140 dB.

Residual AM: (Averaged rms)

Post-detection Noise Bandwidth

300 Hz to 3 kHz 20 Hz to 15 kHz

>85 dB down >78 dB down

Residual FM: (Averaged rms)

CW and up to

1/8 maximum allowable peak

Up to maximum allowable peak

Post-detection

Noise

Bandwidth

230 to 550 MHz

deviation

300 Hz

3 kHz

<5 Hz

20 Hz to

15 kHz to

deviation

300 Hz

3 kHz

20 Hz to

15 kHz

<15 Hz <15 Hz <30 Hz

Note: Residual FM decreases by approximately 1/2 for each divided frequency range until limited by broadband 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.

OUTPUT CHARACTERISTICS

Range: 10 dB steps and 18 dB vernier provide output power settings from +19 to -145 dBm (2V to 0.013µ) into 50

Ω

Level Flatness: <±0.5 dB from 0.5 to 512 MHz referred to output at 50 MHz. (Flatness applies to +13 to -7 dBm and for top 10 dB of vernier range.)

These specifications are given for the 8640B internal reference. When using an external reference, drift in the locked mode will depend on the external reference characteristics.

1-9

Model 8640B

TM 9-4935-601-14-7&P

Table 1-1. Specifications (3 of 5)

OUTPUT CHARACTERISTICS (Cont'd)

Impedance: 50Q, ac coupled, 40 Vdc maximum,

VSWR <2.0 on 2V and 1V output ranges; <1.3 on all other ranges.

Reverse Power: 20 dBm maximum on 2V and 1V output ranges; 27 dBm maximum on all other ranges.

Auxiliary Output: Rear panel BNC output is >-5 dBm into 50

Ω

, source impedance is approximately 500

Ω

Leakage: (With all unused outputs terminated properly.) Leakage limits are below those specified in MIL-I-6181D. Furthermore, less than 3

µV is induced in a 2-turn, 1-inch diameter loop 1 inch away from any surface and measured into a

Ω

receiver. This permits receiver sensitivity measurements to at least <0.03µV in a shielded system.

Level Accuracy:

Using Top 10 dB of

Vernier Range

Using

Full

Vernier

Range

Output Level

(dBm)

Total Accuracy as Indicated on

Level Meter

+19 to

-7

±1.5 dB

-7 to

-47

±2.0 dB

-47 to

-137

±2.5 dB

+19 to

-145

Add

±0.5 dB

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.

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 mV to 1 Vrms into 600

Ω

Optional: (Internal Variable Audio Oscillator Option

001).

Frequency: Variable 20 Hz to 600 kHz, ±10% in 5, decade continuous bands plus fixed 400 Hz and 1 kHz ±2%.

Output Level: 20 mV to 3V into 60012.

Total Harmonic Distortion:

<0.25% 400 Hz and 1 kHz fixed tones

<0.5% 20 Hz to 2 kHz

<1.0% 2 kHz to 600 kHz

Amplitude Modulation

(AM specifications apply to the top 10 dB of output vernier range unless otherwise specified.)

Depth: 0 to 100% for output level range of +13 dBm and below and for top 10 dB of vernier range.

AM Rates: INT and EXT ac; 20 Hz to AM 3 dB bandwidth below. EXT dc; dc to AM 3 dB bandwidth below.

AM 3 dB Bandwidth: (See Figure 1-4).

Frequency

Bands

0.5 - 2 MHz

2 - 8 MHz

8 - 512 MHz

20 kHz

40 kHz

60 kHz

0 to

50% AM

50 to

90% AM

12.5 kHz

25 kHz

50 kHz

AM is possible above +13 dBm as long as the combination of the AM depth plus carrier output level does not exceed

+19 dBm.

1-10

Model 8640B

TM 9-4935-601-14-7&P

Table 1-1. Specifications (4 of 5)

MODULATION CHARACTERISTICS (Cont'd)

AM Distortion: (at 400 Hz and 1 kHz rates)

Frequency

Bands

0.5 to 512 MHz

0 to

50% AM

<1%

50 to

90% AM

<3%

External AM Sensitivity: (400 Hz and 1 kHz rates) (0.1

± 0.005)% AM per mV peak into 600

Ω

with AM vernier at full CW position.

Amplitude Modulation (Cont'd)

Indicated AM Accuracy: (400 Hz and 1 kHz rates using internal meter)

±8% of reading on 0 - 10 scale.

±9% of reading on 0 - 3 scale (for greater than 10% of full scale).

Peak Incidental PM (at 30% AM)

Less than 0.15 radians, 0.5 to 128 MHz.

Less than 0.3 radians, 128 to 512 MHz.

Peak Incidental Frequency Deviation: Equals PEAK

INCIDENTAL PM x MODULATION RATE.

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 at maximum vernier

Peak Input Required

Pulse Modulation

(Specifications apply for top 10 dB of output vernier range.)

0.5 - 1

<9 µs

1 - 2

<4 µs

2-8

<2 µs

50 Hz to

50 kHz

50 Hz to

100 kHz

8- 32

50 Hz to

250 kHz

10 µs

Nominally +0.5V (+5V max) waveform, return to zero, into

Ω

Schmitt trigger.

5 µs

>40 dB

<1 µs

2 µs

32 - 512

50 Hz to

500 kHz

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

Frequency Modulation

Maximum Peak

Deviation (kHz)

160

320

640

1280

2560

5120

FM 3 dB Bandwidth:

Internal and External ac; 20 Hz to 250 kHz.

External dc; dc to 250 kHz.

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.

With 86408 in, LOCKED MODE, external FM is possible only for rates greater than 50 Hz.

1-11

Model 8640B

TM 9-4935-601-14-7&P

Table 1-1. Specifications (5 of 5)

MODULATION CHARACTERISTICS (Cont'd)

Frequency Modulation (Cont'd)

Indicated FM Accuracy:

(400 Hz and 1 kHz rates using internal meter) ±10% of meter reading (for greater than 10% of full scale).

Incidental AM: (at 400 Hz and 1 kHz rates)

<0.5% AM for FM up to 1/8 maximum allowable deviation.

<1% AM for FM at maximum allowable deviation.

COUNTER CHARACTERISTICS

External RF Input:

Frequency Range: 1 Hz to 550 MHz.

Sensitivity: 100 mVrms, ac only, into 50

Ω

1 (-7 dBm).

Maximum Input: 1.3 Vrms (+15 dBm).

External Count Resolution: 6-digit LED DISPLAY

Mode Normal

0 - 10 MHz 100 Hz

0 - 550 MHz 10 kHz

Expand X10 Expand X100

10 Hz

1 kHz

1 Hz

100 Hz

External Reference Input: 5 MHz, nominally >0.5 Vp-p

(5V maximum) into 1000

Ω

Internal Reference Characteristics: (after 2-hr.

warm-up)

Accuracy: (after calibration at 25°C)

Better than +1 ppm for 15 to 35°C.

Better than ±3 ppm for 0 to 55°C.

Drift Rate:

Time: <0.05 ppm per hr, <2 ppm per year.

Temperature: <2 ppm total variation for room ambient 15 to 35°C.

Line Voltage: <0.1 ppm.

Frequency Tuning:

>±20 ppm using internal time base vernier.

Rear Output: nominally >0.5 Vp-p into 500

Ω

. This will drive another 8640B.

Operating Temperature Range: 0 to 55°C.

GENERAL CHARACTERISTICS

Dimensions:

Power Requirements: 100, 120, 220, and 240 volts,

+5%, -10%, 48 to 440 Hz; 175 VA maximum. 71/2 ft. (2,29 m) power cable furnished with mains plug to match destination requirements.

Weight: Net, 45 lb (20,4 kg).

Dimensions are for general information only. If dimensions are required for building special enclosures, contact your

HP office.

1-12

Model 8640B

Instrument Type

Adjustable Stub

20 dB Amplifier

40 dB Amplifier

One-Inch Loop Antenna

10 dB Step Attenuator

Calibrated Step

Attenuator

TM 9-4935-601-14-7&P

Table 1-2. Recommended Test Equipment (1 of 7)

Critical Specifications

Length: >50 cm

Range: to 550 MHz

Range: 0.5 - 520 MHz

(3 required)

Flatness over Range: ±2 dB

Impedance: 50

Ω

Noise Figure: <5 dB

Range: 400 - 1200 MHz

Gain: >20 dB

Flatness: ±2 dB

Impedance: 50

Ω

Noise Figure: <5 dB to 1 GHz

Range: 5 Hz to 100 kHz

Gain: 20 and 40 dB ±1 dB

Input Impedance: >5 k

Ω

Output Impedance: 50

Ω

Noise: <25 µVrms referred to input

Output: >1 Vrms into 5012

Range: 20 Hz to 100 kHz

Gain: 40 ±1 dB

Input Impedance: 50

Ω

Noise Figure: <3 dB when driven from

Ω

Output Level: >100 mV in 50

Ω

To ensure measurement accuracy, no substitution is possible. Fabrication depends upon machining and assembling to very close tolerances.

Attenuation: 0 - 120 dB in 10 dB steps

Range: 0.45-550 MHz

Accuracy: ±1.5 dB to 90 dB

±0.3 dB to 120 dB (below 1 kHz)

Suggested Model

GR 874-D50L

HP 8447A

Gain: 20 to 25 dB

HP 8447B

HP 465A

HP 08640-60506

HP 08640-60501

HP 355D

Attenuation: 0 - 120 dB in 10 dB steps

Accuracy: ± (0.02 ± 0.015 dB/10 dB step) at 3 MHz

HP 355D

Option H36

*P = Performance; A = Adjustment; T = Troubleshooting

1-13

Use*

P,A

Model 8640B

Instrument Type

3 dB Attenuator

10 dB Attenuator

20 dB Attenuator

Crystal Detector

Digital Voltmeter

Digital to Analog

Converter

Directional Coupler

Distortion Analyzer

FM Discriminator

TM 9-4935-601-14-7&P

Table 1-2. Recommended Test Equipment (2 of 7)

Critical Specifications

Accuracy: ±0.5 dB to 550 MHz

Suggested Model

HP 8491A

Option 003

HP 8491A

Option 010

HP 8491A

Option 020

HP 8471A Range: 0.45 - 550 MHz

Low Level Sensitivity: >0.35 mV/µW

No internal dc return

Range: 10 - 550 MHz

Maximum Sensitivity: at 15 - 17 dBm input

With internal dc return

DC Accuracy: ± (0.01% of reading

+0.02% of range)

AC (True RMS) Accuracy: ±0.1% of reading

Ohms Range: to 1 k

Ω

Accuracy: 1% of full scale

Input Code: 1248 with 1 (on) state positive (compatible with Fredquency Counter)

Output: Compatible with Strip

Chart Recorder

Range: 100 - 550 MHz

Coupling Attenuation: 20 dB

Directivity: 36 dB

VSWR: <1.1:1

Range: 20 Hz to 600 kHz

Distortion Range: <0.1%

Minimum Input: <300 mVrms

HP 423A

HP 3480B/

3484A (with

Options 042,

043)

HP 581A

Option 002

HP 778D

Option 12

HP 333A

Ranges: 100 kHz to 10 MHz

Linear Analog Output: 1V for full scale

HP 5210A

*P = Performance; A = Adjustment: T = Troubleshooting

1-14

Use*

P,A

P,A,T

P,A

Model 8640B

Instrument Type

With Filter Kit

600 Ohm Feedthrough

520 MHz Notch

Filter

4 MHz Low Pass Filter

(2 required)

1.5 MHz Low Pass

Filter

15 kHz Low Pass

Filter

3 kHz Low Pass

Filter

Frequency Counter

TM 9-4935-601-14-7&P

Table 1-2. Recommended Test Equipment (3 of 7)

Critical Specifications

Output Low Pass Filters for FM Discriminator (20 kHz and 1 MHz

Butterworth filters)

Impedance: 6002 ± 1% shunt

Connectors: BNC

Notch Frequency Accuracy:

500 - 540 MHz

Notch Rejection: >60 dB

See Figure 1-7

4 MHz low pass (3 pole)

Impedance: 50

Ω

VSWR: <1.5:1

Ripple: <±0.2 dB

1.5 MHz low pass (3 pole)

Impedance: 50

Ω

VSWR: <1.5:1

Ripple: <±0.2 dB

15 kHz low pass (7 pole)

Impedance: 50

Ω

Ripple: <±0.2 dB

3 kHz low pass (5 pole)

Impedance: 50

Ω

Ripple: <±0.2 dB

Range: to 550 MHz

Input Sensitivity: <100 mV

Inputs: 50

Ω

and high impedance

(1 M

Ω

)

Standard Reference Accuracy:

<3 x 10

-7

/month aging rate

<5 x 10

-9

/s rms short term stability

<±2.5 x 10

-6

, 0 - 50°C temperature stability

Suggested Model

With HP

10531A

HP 11095A

HP 08640-60502

CIR-Q-TEL

FLT/21B-4-3/

50-3A/3B

CIR-Q-TEL

FLT/21B-

1500K-3/50-

3A/3B

CIR-Q-TEL

FLT/21B-15K-

7/50-3A/3B

CIR-Q-TEL

FLT/21B-3K-

5/50-3A/3B

HP 5327C

Optional Reference Accuracy:

<3 x 10

-9

<1 x 10

-10

/day aging rate

/s rms short term stability

<1 x 10

-8

, 0 - 50°C temperature stability

Option H49

*P = Performance; A = Adjustments; T = Troubleshooting

1-15

P,A

Use*

P,A

P,A,T

Model 8640B

Instrument Type

Frequency Counter

(Cont'd)

Function Generator

FM Linearity Circuit

Mixer (3 required)

Noise Phase Lock

Circuit

Oscilloscope

Power Meter

With Thermistor

Mount

Power Meter

With Power Sensor

(Thermocouple)

Pulse Generator

Quartz Oscillator

TM 9-4935-601-14-7&P

Table 1-2. Recommended Test Equipment (4 of 7)

Critical Specifications

Optional Digital Output: 1248 with 1

(on) state positive (compatible with

D/A Converter)

Range: 0.1 Hz to 1 kHz

Output Impedance: 600

Ω

Output Level: >1 Vpk

See Figure 1-8

Double Balanced

Range: 0.45 - 550 MHz

See Figure 1-9

50 MHz Real Time

Sensitivity: 5 mV/division

Internal/External Sweep and

Triggering

Range: 0.45 - 550 MHz

Input: -20 to +10 dBm

Accuracy: 1%

VSWR: <1.3:1

Option H63

Range: 10 - 550 MHz

Input Level: -10 to +20 dBm

Accuracy: ±1% of reading

VSWR: <1.18:1

Suggested Model

Option 003

HP 3300A

HP 08640-60503

HP 10514A

HP 08640-60504

HP 180A/1801A/

1820C

HP 432A

With HP 478A

HP 435A

With HP 8481A

P,A

Use*

P,A,T

P,A

P,T Range: 50 Hz to 500 kHz

Output: >1V into 50

Ω

Pulse Width: down to 1 µs

Transition Time: <50 ns

Output: 1 MHz (level compatible with Frequency Counter)

Stability: <5 x 10

-18

/24 hours

<5 x 10

-12

HP 8003A

HP 105B

*P = Performance; A = Adjustments; T = Troubleshooting

1-16

Model 8640B

Instrument Type

RMS Voltmeter

Signal Generator

Audio Spectrum

Analyzer

TM 9-4935-601-14-7&P

Table 1-2. Recommended Test Equipment (5 of 7)

Critical Specifications

Range: 10 Hz to 100 kHz

Reading: True rms (ac only)

Voltage Range: 1 mV to 10V full scale

Accuracy: 1% of full scale 50 Hz to 50 kHz

Scale: Voltage and dB

Range: 0.45 - 550 MHz

Output: >13 dBm into 50

Ω

Drift: <20 ppm/10 min.

SSB Phase Noise: >130 dB down from 230 to 450 MHz increasing linearly to >122 dB down at

550 MHz (stated in a 1 Hz bandwidth at 20 kHz offset from carrier) and decreasing approximately 6 dB/ octave for each divided down range but need not be less than 140 dB down

Residual FM: <15 Hz rms in 20 Hz to 15 kHz post-detection noise bandwidth; < 5 Hz rms in 0.3-3 kHz post detection noise bandwidth

Aux RF Out: >-5 dBm

Leakage: <3 µV induced in a 2-turn,

1-inch diameter loop 1 inch away from any surface and measured into a 50n receiver.

FM: dc coupled; at least 40 kHz deviation for 1V input

Suggested Model

HP 3400A

HP 8640A

Range: 20 - 200 kHz

Amplitude Calibration:

Display Accuracy: ±0.25 dB/dB but not more than 1.5 dB over

70 dB dynamic range

Flatness: ±0.2 dB

Vertical Reference Scale: 10 dB/ division log, 2 dB/division (or less) log, and linear display calibration

Average Noise Level: <-120 dBm

(50

Ω

) with 1 kHz IF bandwidth

Spurious Responses: >60 dB down for

HP 141T/

8552B/8556A nominal specified inputs

*P = Performance; A = Adjustments; T = Troubleshooting

1-17

Use*

P,A

Model 8640B

Instrument Type

Audio Spectrum

Analyzer (Cont'd)

Spectrum Analyzer

Recorder (Strip

Chart)

Temperature Controlled

Chamber

Test Oscillator

TM 9-4935-601-14-7&P

Table 1-2.- Recommended Test Equipment (6 of 7)

Critical Specifications Suggested Model

Tracking Generator:

Flatness: ±0.25 dB

Level: >3 Vrms into 600µ

Range: 0.5 - 1200 MHz

Amplitude Calibration:

Display Accuracy: ±0.25 dB/dB but not more than 1.5 dB over

70 dB dynamic range

Flatness: ±1 dB

IF Gain Step Accuracy: ±0.2 dB

Vertical Reference Scale: 10 dB/ division log, 2 dB/division (or less) log, and linear display calibration

Average Noise Level: <-102 dBm with 10 kHz IF bandwidth

Spurious Responses: >60 dB down for inputs of -40 dBm or less

Span Width: 0 - 1 GHz

Compatible with Tracking Generator

Range: 0.45 -100 MHz

IF Bandwidths: down to 10 Hz

All other specifications are the same as the HP 141T/8552B/8554B listed above except Span Width which should be 0 - 100 MHz

HP 141T/

8552B/8554B

HP 141T/

8552B/8553B

(should be compatible with

Tracking Generator).

Compatible with Digital to Analog

Converter

Accuracy: 0.5% of full scale

Range: 0 - 55°C

Model 325

Range: 20 Hz to 600 kHz

Output Impedance: 600

Ω

and 50

Ω

Distortion: >40 dB down

HP 680

Statham

HP 652A

Output Level: >1 Vrms

*P = Performance; A = Adjustments; T = Troubleshooting

1-18

P,A

Use*

P,A,T

Model 8640B

Instrument Type

Tracking Generator

Variable Phase Oscillator

Variable Voltage

Transformer

Vector Voltmeter

VSWR Bridge

TM 9-4935-601-14-7&P

Table 1-2. Recommended Test Equipment (7 of 7)

Critical Specifications

Output: to 0 dBm (50

Ω

)

Flatness: ±0.5 dB

Compatible with Spectrum Analyzer

(HP 141T/8552B/8554B)

Output: to 0 dBm (50

Ω

)

Compatible with Spectrum Analyzer,

(HP 141T/8552B/8553B)

Range: 20 Hz to 60 kHz

Output Impedance: 600

Ω

Phase Variability: 0 to 360°

Distortion: >64 dB down

Range: +5% to -10% of nominal line voltage (100, 120, 220 or

240 volts). For 120V, range is 105 - 130 Vrms.

Metered Accuracy: ±1 Vrms

Range: 1 - 550 MHz

Sensitivity: <20µV

Phase Range: +18° full scale down to +6° full scale

Phase Resolution: 0.1°

Phase Accuracy: ±1.5°

Voltage Ratio Accuracy: 0.2 dB

Suggested Model

HP 8444A

HP 8443B

HP 203A

GR W5MT3A

HP 8405A

Range: 0.45 - 550 MHz

Directivity: >40 dB

Connectors: Type N

Wiltron Model

60N50

*P = Performance; A = Adjustments; T = Troubleshooting

1-19

Use*

P,A

Model 8640B

Table 1-3. Recommended Test Accessories

Accessory Type

Adapter (Type N Male and BNC Female connectors)

Adapter (BNC Male and dual Banana post connectors)

Adapter (two SMC Male connectors)

Double Shielded Cable (BNC Male connectors, Coaxial)

Nine-Inch Cable (BNC Male connectors, Coaxial)

Test Cable (48-inch, BNC Male connectors, Coaxial)

Test Cable (SMC Male and BNC Male connectors)

50 Ohm Load (Male, BNC, Coaxial)

Coaxial Short (Male Type N)

Tee (Coaxial, BNC, one Male and two Female connectors)

Voltage Probe (1:1)

Extender Board (20 pins)

Bumpers (2) for Extender Board

5 µ F Capacitor

100 µF Capacitor

0.001 µF Capacitor

0.033 µ F Capacitor

1 k

Ω

Resistor

10 k

Ω

Resistor

SPST Switch

1-20

TM 9-4935-601-14-7&P

Suggested Model

HP 1250-0067

HP 10110A

HP 1250-0827

HP 08708-6033

HP 10502A

HP 10503A

HP 11592-60001

HP 11593A

HP 11512A

HP 1250-0781

HP 10025A

HP 5060-0256

HP 0403-0115

HP 0180-2211

HP 0180-0094

HP 0160-0153

HP 0160-0163

HP 0757-0280

HP 0757-0442

HP 3101-0163

Model 8640B

Figure 1-7. 520/1040 MHz Notch Filter.

Figure 1-8. FM Linearity Circuit.

1-21

TM 9-4935-601-14-7&P

Model 8640B

TM 9-4935-601-14-7&P

Figure 1-9. Noise Phase Lock Circuit.

1-22

Model 8640B

TM 9-4935-601-14-7&P

2-1. INTRODUCTION

2-2. This section explains how to prepare the Model

8640B Signal Generator for use. It explains how to connect the instrument to accept available line voltage, and it also describes bench operation, rack mounting, storage, and shipment.

2-3. INITIAL INSPECTION

2-4. Inspect the shipping container for damage. If the shipping container or cushioning material is damaged it should be kept until the contents of the shipment have been -checked for completeness and the instrument has been checked mechanically and electrically. The

contents of the shipment should be as shown in Figure

1-1, and procedures for checking electrical performance

are given in Section IV. If the contents are incomplete,

SECTION II

INSTALLATION

if there is mechanical damage or defect, or if the instrument does not pass the electrical performance test, notify the nearest Hewlett-Packard office. If the shipping container is damaged, or the cushioning material shows signs of stress, notify the carrier as well as the Hewlett-Packard office. Keep the shipping materials for carrier's inspection. The HP office will arrange for repair or replacement without waiting for claim settlement.

2-5. PREPARATION FOR USE

2-6. Power Requirements

2-7. The Model 8640B requires a power source of 100,

120, 220, or 240 Vac +5-10%, 48 to 440 Hz, single phase. Power consumption is 175 VA maximum.

Figure 2-1. Line Selector

2-1

Model 8640B

2-8. Line Voltage Selection

CAUTION

To prevent damage to the instrument, make the line voltage selection before connecting line power. Also ensure the line power cord is connected to a line power socket that is provided with a protective earth contact.

2-9. A rear panel, line power module permits operation from 100, 120, 220, or 240 Vac. The number visible in the window (located on the module) indicates the nominal line voltage to which the instrument must be connected.

2-10. To prepare the instrument for operation, slide the fuse compartment cover to the left (the line power cable should be disconnected). Pull the handle marked FUSE

PULL and remove the fuse; rotate the handle to the left.

Gently pull the printed circuit voltage selector card from its slot and orient it so that the desired operating voltage

appears on the top-left side (see Figure 2-1).

TM 9-4935-601-14-7&P

Firmly push the voltage selector card back into its slot.

Rotate the FUSE PULL handle to the right, install a fuse of the correct rating, and slide the fuse compartment cover to the right. A complete set of fuses is supplied with the instrument see ACCESSORIES SUPPLIED in

Section I.

NOTE

The correct fuse rating for the line voltage selected in listed on the line power module. More information about fuses is given in the table of

replaceable parts in Section VI

(reference designation is Fl).

2-1 1. Power Cable

2-12. In accordance with international safety standards, this instrument is equipped with a three-wire power cable. When connected to an appropriate power line outlet, this cable grounds the instrument cabinet. The type of power cable plug shipped with each instrument

depends on the country of destination. Refer to Figure

2-2 for the part numbers of the power cable plugs

available.

Figure 2-2. Power Cables Available.

2-2

Model 8640B

WARNING

b. The power cable plug shall only be 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 b; c4nnected 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 cord is wired correctly (see

Service Sheet 22).

2-13. Mating Connectors

2-14. Mating connectors used with the Model 8640B should be either 50 ohm-type BNC male or Type N male connectors that are compatible with US MIL-C-39012.

2-15. Operating Environment 2-16. The operating environment should be within the following limitations:

Temperature ..............................................0°C to +55°C

Humidity....................................................<95% relative

Altitude........................................................<15,000 feet

2-17. A forced-air cooling system is used to maintain the operating temperature required within the instrument. The air intake and filter are located on the rear panel, and warm air is exhausted through perforations in the right-hand side panel. When operating the instrument, choose a location that provides at least three inches of clearance at the rear and two inches clearance at the right side. The clearances provided by the plastic feet in bench stacking

2-3

TM 9-4935-601-14-7&P

and the filler strips in rack mounting are adequate for the top and bottom cabinet surfaces.

2-18. Bench Operation

2-19. The instrument cabinet has plastic feet and a foldaway tilt stand for convenience in bench operation.

The tilt stand raises the front of the instrument for easier viewing of the control panel, and the plastic feet are shaped to make full-width modular instruments selfaligning when stacked.

2-20. Rack Mounting

2-21. A Rack Mounting Kit is available to install the instrument in a 19-inch rack. Rack Mounting Kits may be obtained through your nearest Hewlett-Packard

Office by ordering HP Part Number 5060-8740. This kit contains all necessary hardware and installation instructions for mounting the instrument on a rack with

19-inch spacing (see Figure 2-3).

2-22. STORAGE AND SHIPMENT

2-23. Environment

2-24. The instrument should be stored in a clean, dry environment. The following environmental limitations apply to both storage and shipment:

Temperature ...........................................-40°C to +75°C

Humidity....................................................<95% relative

Altitude....................................................... <25,000 feet

2-25. Packaging

2-26. Original Packaging. Containers and materials identical to those used in factory packaging are available through Hewlett-Packard offices. If the instrument is being returned to Hewlett-Packard for servicing, attach a tag indicating the type of service required, return address, model number, and full serial number. Also, mark the container FRAGILE to assure careful handling. In any correspondence, refer to the instrument by model number and full serial number.

2-27. Other Packaging. The following general instructions should be used for re-packaging with commercially available materials: a. Wrap the instrument in heavy paper or plastic. (If shipping to a Hewlett-Packard office or service center, attach a tag indicating the type of service required, return address, model number, and full serial number.)

Model 8640B b. Use a strong shipping container. A doublewall carton made of 350-pound test material is adequate.

c. Use enough shock-absorbing material (3to 4-inch layer) around all sides of the instrument to provide a firm cushion and prevent movement inside the

TM 9-4935-601-14-7&P

container. Protect the control panel with cardboard.

d. Seal the shipping container securely.

e. Mark the shipping container FRAGILE to assure careful handling.

Figure 2-3. Preparation for Rack Mounting.

2-4

Model 8640B

TM 9-4935-601-14-7&P

3-1. INTRODUCTION

3-2. This section describes the functions of the controls and indicators of the Model 8640B Signal Generator. It explains how to set the frequency, amplitude, and modulation controls, and covers such operator maintenance as fuse and indicator lamp replacement and fan filter cleaning.

3-3. PANEL FEATURES

3-4. Front panel controls, indicators, and connectors are

shown and described in Figure 3-2. Rear panel controls

and connectors are shown and described in Figure 3-3.

3-5. OPERATOR'S CHECKS

3-6. Use the operator's checks in Figure 3-4 to verify

proper operation of the Signal Generator's main functions.

3-7. OPERATING INSTRUCTIONS

3-8. Figures 3-5 and 3-6 explain how to set the frequency, amplitude, and modulation controls. Figure

3-5 also explains how to use the frequency counter and

phase lock controls.

3-9. OPERATOR'S MAINTENANCE

3-10. Fuse. The main ac line fuse is located on the rear panel next to the line power cable jack. To remove the fuse, first remove the line power cable from its jack.

Slide the fuse compartment cover to the left, then pull the handle marked FUSE PULL and remove the fuse.

CAUTION

Be sure to select the correct fuse rating for the selected line voltage

(see LINE VOLTAGE SELECTION in

Section II); fuse ratings are listed on

the fuse compartment.

3-11. Fan. The cooling fan's filter is located on the rear panel. To service the fulter use a No. 2 Pozidriv screwdriver (HP 8710-0900) to remove the four screws that hold the filter to the rear panel. Then clean it, using

SECTION III

OPERATION

a solution of warm water and soap, or replace it, using the part number listed in the table of replaceable parts in

Section VI.

3-12. The fan motor has factory lubricated, sealed bearings and requires no periodic maintenance.

3-13. Lamp Replacement. Figure 3-1 explains how to

replace the lamp located in the line power switch.

3-14. Meter Zeroing. To mechanically zero the front panel meter, set LINE switch to OFF and place instrument in its normal operating position. Turn adjustment screw cw until indicator indicates zero, then turn adjustment slightly ccw to free mechanism from adjusting peg.

Figure 3-1. Lamp Replacement.

3-1

Model 8640B

FRONT PANEL FEATURES

TM 9-4935-601-14-7&P

Meter Function: interlocked buttons select one of three functions.

DEVIATION set to 80 kHz, a meter reading of

7.2 indicates that deviation is 72 kHz).

AM: meter indicates percent of amplitude modulation.

FM: meter indicates peak frequency deviation.

LEVEL: meter indicates RF output level in

Vrms or dBm 50

Ω

LEVEL VOLTS: 0-3 and 0-10 scales are read in microvolts, millivolts, or volts depending upon setting of OUTPUT LEVEL controls (e.g., with

OUTPUT LEVEL set to approximately 20 mVOLTS, a meter reading of 2.4 indicates that actual level is 24 mVrms). The -10 to +3 dB scale is read relative to the OUTPUT LEVEL switch dBm scale.

SCALE: annunciator lamps light to indicate applicable meter scale. Meter scale is automatically selected.

Output Problem Annunciators: lamps light to indicate that modulation or OUTPUT LEVEL settings are causing generator to be uncalibrated.

Meter: automatically ranges to one of three scales, read according to meter function.

AM X 10 %: 0-3 scale is read 0-30%; 0-10 scale is read 0-100%.

REDUCE PEAK POWER: indicates a combination of OUTPUT LEVEL setting and amplitude modulation that exceeds +19 dBm power output.

FM kHz/MHz: 0-3, 0-5, and 0-10 scales are read in kHz or MHz, depending upon setting of

PEAK DEVIATION switch (e.g., with PEAK

REDUCE FM VERNIER: indicates that an external FM input level or vernier setting is causing FM deviation to exceed limits.

Figure 3-2. Front Panel Controls, Indicators, and Connectors (1 of 4).

3-2

Model 8640B

TM 9-4935-601-14-7&P

FRONT PANEL FEATURES

REDUCE PEAK DEVIATION: indicates PEAK

DEVIATION setting is too high for the selected frequency range.

COUNTER MODE: Buttons control operation of frequency counter.

EXPAND: X10 expands resolution one digit, moving the decimal point one place to the left;

X100 expands resolution two digits, moving the decimal point two places to the left.

RF ON/OFF: enables or disables the RF output.

RF OUTPUT: RF output through Type N female connector. (Connector meets US MIL C-39012 50 ohm ac coupled source impedance CAUTION 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).

NOTE

EXPAND X10 and EXPAND X100 buttons are interlocked so that only one button can be depressed at a time.

10 OUTPUT LEVEL: the switch controls a 10 dB step attenuator that sets the output level range.

Calibrated concentric vernier sets actual output level within an 18 dB range (the meter gives additional resolution).

LOCK: phase locks Signal Generator to the internal (or to an external) crystal reference.

Display indicates lock frequency; loss of lock causes display to flash and indicate actual frequency of Signal Generator.

NOTE

For optimum operation, use the vernier in the top 10 dB of its range.

11 FINE TUNE: fine frequency control.

12 FREQUENCY TUNE: coarse frequency control.

INT: programs counter to count frequency of

Signal Generator.

EXT 0-10, EXT 0-550: programs counter to count frequency of signal at COUNTER IN.

PUT jack; also selects counter frequency range in MHz.

13 RANGE: selects one of ten octave frequency bands. The 512-1024 MHz/Doubler position gives

256-5 l 2 MHz at RF OUTPUT, but the

FREQUENCY MHz readings and FM meter indications are corrected for use with an RF doubler connected to RF OUTPUT.

FREQUENCY MHz: counter readout indicates RF frequency in MHz. Flashing display indicates loss of phase lock. The OVERFLOW lamp lights to indicate that significant data is not being displayed.

14 COUNTER INPUT: external input to frequency counter; impedance is 50 ohms.

TIME BASE VERNIER: used as a fine frequency tune when in lock mode to give continuous tuning between lock points (the use of the COUNTER

MODE EXPAND X10 control is necessary on some ranges to tune over the full range). When control is not in CAL position, the UNCAL lamp lights to indicate that the counter is uncalibrated.

CAUTION

Do not apply a dc voltage or >+15 dBm to COUNTER INPUT.

Figure 3-2. Front Panel Controls, Indicators, and Connectors (2 of 4)

3-3

Model 8640B

FRONT PANEL FEATURES

TM 9-4935-601-14-7&P

15 FM: selects frequency modulation and source.

OFF: no FM.

INT: FM by internal oscillator.

AC: FM by external source through FM INPUT jack (>20 Hz, ac + dc <5 Vpk).

DC: FM by external source through FM INPUT jack (ac + dc <5 Vpk).

CAL: used to calibrate external modulation input (do not use when phase locked).

16 PEAK DEVIATION: switch and concentric vernier vary FM frequency deviation (as indicated on the meter). Vernier range is from zero to the peak deviation selected by the switch.

17 FM INPUT/OUTPUT: 600 ohm input for external

FM; nominally 1 Vpk (0.7071 Vrms) required for full peak deviation selected by PEAK DEVIATION switch (never more than 5 Vpk). Output for internal oscillator whenever FM selector is set to

INT (600 ohm source impedance); level controlled by

AUDIO OUTPUT LEVEL.

18 MODULATION FREQUENCY: switch selects 400

Hz or 1000 Hz. With Option 001 Variable

Modulation Oscillator (shown), switch also selects multiplier. Vernier, with multiplier, sets frequency from 20 Hz to 600 kHz.

19 AM INPUT/OUTPUT: 600 ohm input for external

AM; 1 Vpk (0.7071 Vrms) required for 100% modulation (never more than 5 Vpk). Input for pulse modulation (50 ohm): >1 Vpk positive pulse required to turn on RF. Output for internal oscillator whenever AM selector is set to INT (600 ohm source impedance); level controlled by AUDIO OUTPUT

LEVEL.

NOTE

With the Option 001 Variable

Modulation Oscillator, AM OUTPUT and FM OUTPUT are in parallel.

Parallel load should be ->600 ohms.

Figure 3-2. Front Panel Controls, Indicators, and Connectors (3 of 4)

3-4

Model 8640B

TM 9-4935-601-14-7&P

FRONT PANEL FEATURES

20 MODULATION: vernier varies amplitude modulation from 0 to 100% (as indicated on the meter).

21 AUDIO OUTPUT LEVEL: control varies level of signal from AM and/or FM OUTPUT jacks

(calibration gives voltage into 600

Ω

22 LINE: switch applies or removes AC power. The button is lit when ON.

23 AM: selects amplitude modulation and source.

AC: AM by external source through AM INPUT jack (>20 Hz, ac + dc <5 Vpk).

DC: AM by external source through AM INPUT jack (ac + dc <5 Vpk).

PULSE: when selected with no modulation, it disables the RF output; a positive pulse at AM

INPUT pulses on the RF.

24 Mechanical Meter Zero: sets meter suspension so that meter indicates zero when power is removed from instrument and instrument is in normal operating position.

OFF: no AM.

INT: AM by internal oscillator.

Figure 3-2. Front Panel Controls, Indicators, and Connectors (4 of 4)

3-5

Model 8640B

REAR PANEL FEATURES

TM 9-4935-601-14-7&P

AUX RF OUT: nominal -5 dBm auxiliary RF output; 500 ohm source impedance. Signal does not contain amplitude or pulse modulation (however, it does contain FM). On the 512-1024

MHz/Doubler Band the auxiliary RF output is onehalf the frequency of the indicated RF frequency.

TIME BASE Reference In/Out: input for external, 5 MHz time base reference that is >100 mVrms; load impedance is 1 k

Ω

. Output for internal, 5 MHz time base reference, level is 3 Vrms into an open circuit; source impedance is 500 ohms.

TIME BASE Reference INT/EXT: switch selects function of IN/OUT jack. INT position applies internal reference to jack. EXT position feeds external reference from jack to time base.

NOTE

Since the phase lock reference is the

5 MHz time base, the Model 8640B can be phase locked to an external reference (such as another Model

8640B) by using the TIME BASE

Reference jack and switch.

Line Power Module: permits operation from 100,

120, 220 or 240 Vac. The number visible in window indicates nominal line voltage to which instrument

must be connected (see Figure 2-1). Center

conductor is safety earth ground.

WARNING

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. (See

Section II).

Serial Number Plate: first four digits of serial number comprise the prefix; last five digits form sequential suffix that is unique to each instrument.

The plate also indicates any options supplied with instruments.

Figure 3-3. Rear Panel Controls and Connectors

3-6

Model 8640B

OPERATOR'S CHECKS

TM 9-4935-601-14-7&P

Initial Control Settings

a. Push LINE switch (22) to ON. Set TIME BASE INT/EXT switch (on rear panel) to INT.

b. Set the controls as follows:

1 Meter Function ............................................................................... LEVEL

5 COUNTER MODE: EXPAND ...................................................... Off (Out)

LOCK................................................... Off (Out)

SOURCE .............................................. INT (In)

7 TIME BASE VERNIER ....................................................................... CAL

23 AM .....................................................................................................OFF

21 AUDIO OUTPUT LEVEL .................................................................... ccw

20 MODULATION .................................................................................... ccw

18 MODULATION FREQUENCY ........................................................400 Hz

15 FM ....................................................................................................OFF

16 PEAK DEVIATION .......................................................................... 5 kHz

16 PEAK DEVIATION Vernier ................................................................. ccw

13 RANGE .....................................................................................0.5-1 MHz

12 FREQUENCY TUNE ................................Centered (Four turns from stop)

11 FINE TUNE ................................................................................Centered

10 OUTPUT LEVEL ..................................................................100 mVOLTS

8 RF ON/OFF .........................................................................................ON

Figure 3-4. Operator's Checks (1 of 5)

3-7

Model 8640B

OPERATOR'S CHECKS

TM 9-4935-601-14-7&P

Counter and RF Oscillator

c. Use a Type N to BNC adapter and a BNC to BNC cable to connect RF OUTPUT 9 to COUNTER INPUT 14 d. Adjust FREQUENCY TUNE 12 and FINE TUNE 11 until FREQUENCY 6 reads 0.75000 MHz. Set COUNTER

MODE EXPAND 5 to X10; FREQUENCY should read about .750000 MHz (the reading should shift one place to the left). Set COUNTER MODE EXPAND to X100; FREQUENCY should read about 500000 MHz (the reading should shift one additional place to the left with the decimal point and the seven no longer displayed; the OVERFLOW annunciator lamp should light).

e. Set COUNTER MODE EXPAND 5 to OFF (buttons out). With RANGE 13 set as follows, FREQUENCY 6 should read approximately as shown:

Figure 3-4. Operator's Checks (2 of 5)

3-8

Model 8640B

TM 9-4935-601-14-7&P

OPERATOR'S CHECKS

RANGE MHz

0.5-1

1-2

2-4

4-8

8-16

16-32

32-64

64-128

128-256

256-512

512-1024

FREQUENCY MHz

0.75000

01.5000

03.0000

06.0000

12.0000

024.000

048.000

096.000

0192.00

0384.00

0768.00

Phase Lock

f. Set RANGE 13 to 256-512 MHz. Note that the right-hand digit on the FREQUENCY display 6 flickers between two digits. Set COUNTER MODE LOCK 5 to ON; the flickering should stop. Slowly adjust FINE TUNE; the

FREQUENCY reading should not change. Adjust FREQUENCY TUNE 12 ; the FREQUENCY display should flash at about a 2 Hz rate and the reading should change (the reading should follow FREQUENCY TUNE).

RF Output

g. Set COUNTER MODE LOCK 5 to OFF and Source 5 to EXT 0-550. Adjust FREQUENCY TUNE 12 until

FREQUENCY 6 reads 0384.00 MHz. Step through the ranges as specified in step e, setting the COUNTER MODE

EXPAND and Source (EXT) controls 5 to obtain appropriate resolution; FREQUENCY should read approximately as shown in step e.

NOTE

With RANGE set to 512-1024 MHz, FREQUENCY will read approximately 0384.00 MHz (the actual frequency at RF OUTPUT).

Meter

h. Set OUTPUT LEVEL 10 to 500 mVOLTS; the meter 3 should indicate 5 on the 0-10 SCALE (the 0-10 SCALE annunciator 2 should be lit).

Figure 3-4. Operator's Checks (3 of 5)

3-9

Model 8640B

OPERATOR'S CHECKS

TM 9-4935-601-14-7&P

i. Slowly reduce OUTPUT LEVEL 10 to 200 mVOLTS; the meter 3 should autorange to the 0-3 SCALE when the indicator passes approximately 3 on the 0-10 SCALE.

j. With OUTPUT LEVEL 1 set to 200 mVOLTS, the meter 3 should indicate 2 on the 0-3 SCALE. Slowly increase

OUTPUT LEVEL to 500 mVOLTS; the meter should autorange to the 0-10 SCALE when the indicator passes approximately 3 on the 0-3 SCALE.

Amplitude Modulation

k. Set Meter Function 1 to AM and AM 23 to INT. Slowly turn Modulation 20 clockwise. When the meter indicates 10

(i.e., 100% modulation) set OUTPUT LEVEL 10 to +16 dBm; the REDUCE PEAK POWER annunciator 4 should light.

Frequency Modulation

Set AM 23 to OFF (the annunciator should go out) and FM 15 to INT. Set Meter Function 1 to FM and check that

PEAK DEVIATION 16 is set to 5 kHz and the vernier is full counterclockwise; the meter 3 should indicate 0.

Figure 3-4. Operator's Checks (4 of 5)

3-10

Model 8640B TM 9-4935-601-14-7&P

OPERATOR'S CHECKS

m. Turn the PEAK DEVIATION vernier (16) full clockwise; the meter (3) should indicate approximately 5 and the

REDUCE FM VERNIER annunciator (4) should light.

n. Reduce FM vernier (16) until meter reads 5 kHz (the annunciator should go out). Check that RANGE (13) is set to 0.5-1 MHz, and set PEAK DEVIATION (16) to 10 kHz; the REDUCE PEAK DEVIATION annunciator (4) should light and the meter should indicate 0.

o. Set RANGE (13) to 1-2 MHz (the annunciator should go out) and turn the PEAK DEVIATION vernier (16) full counterclockwise; the meter (3) should indicate 0 on the 0-10 SCALE.

Modulation Oscillator

p. Using the BNC to BNC cable, connect FM OUTPUT (17) to COUNTER INPUT (14). Set COUNTER MODE

EXPAND (5) to X100 and Source (5) to EXT 0-10. Set AUDIO OUTPUT LEVEL (21) to 1 V and MODULATION

FREQUENCY (18), in turn, to 400 Hz and 1 kHz; the FREQUENCY readout (6) should display approximately

".000400" and ".001000" MHz.

Figure 3-4. Operator's Checks (5 of 5)

3-11

Model 8640B

SETTING FREQUENCY AND AMPLITUDE

TM 9-4935-601-14-7&P

Frequency

a. Set COUNTER MODE (5) to INT and TIME BASE VERNIER (7) to CAL.

b. Set RANGE (13) to span the desired frequency.

c. Use FREQUENCY TUNE (12) and FINE TUNE (11) to set the Signal Generator to the desired frequency.

d. Normally, the decimal point on the FREQUENCY display (6) is automatically set by the RANGE control (13). For more resolution, set COUNTER MODE EXPAND (5) to X10 or X100.

e. To phase lock the generator's output, set COUNTER MODE LOCK (5) to ON; use TIME BASE VERNIER (7) as the fine frequency tune. On some frequency bands it will be necessary to use the COUNTER MODE EXPAND controls to tune between adjacent counts.

Figure 3-5. Setting the Frequency and Amplitude Controls (1 of 3)

3-12

Model 8640B TM 9-4935-601-14-7&P

SETTING FREQUENCY AND AMPLITUDE

NOTE

If the OVERFLOW annunciator lamp is lit, the generator will not enter phase lock. If the TIME

BASE VERN is not in the CAL position, the counter will not be calibrated.

f. Whenever phase lock is lost, the FREQUENCY display (6) will flash. To re-establish phase lock, set COUNTER

MODE LOCK (5) to OFF; re-tune (if necessary) with FREQUENCY TUNE (12) and FINE TUNE (11), and set

COUNTER MODE LOCK to ON.

NOTE

To get an accurate indication of frequency when not phase locked, set TIME BASE VERNIER (7) to CAL.

g. To use an external frequency doubler, connect to RF OUTPUT (9) and set RANGE (13) to 512-1024

MHz/DOUBLER. The FREQUENCY display (5) will indicate the frequency out of doubler (i.e., the FREQUENCY display indicates twice the frequency at RF Output).

Amplitude

a. Use the OUTPUT LEVEL switch and vernier (11) to set the desired signal level (there are two scales, rms volts and dBm). For optimum operation, use the vernier in the top 10 dB of its range. To enable the RF signal, set the

RF ON/OFF switch (8) to ON.

NOTE

The RF ON/OFF switch may be wired to turn off only the amplitude modulator. This allows the

RF Oscillator to remain warmed up, the Auxiliary RF Output to remain on, and the counter and phase lock to remain operating. If it is desirable to switch both the modulator and the oscillator

off, the RF ON/OFF function may be easily modified (see Service Sheet 5 in Section VIII).

Figure 3-5. Setting the Frequency and Amplitude Controls (2 of 3)

3-13

Model 8640 B TM 9-4935-601-14-7&P

SETTING FREQUENCY AND AMPLITUDE

b. For better voltage and dBm resolution, set Meter Function (1) to LEVEL. The meter (3) is read in conjunction with the OUTPUT LEVEL controls (10) (e.g., with OUTPUT LEVEL set to approximately 20 mVOLTS, a meter reading of 2.1 indicates that the actual level is 21 mVrms).

c. If a 50 ohm to 75 ohm adapter (consisting of a 25 ohm series resistor) is connected to RF OUTPUT (9), the

OUTPUT LEVEL (10) voltage scale will be correct if the instrument is used with 75 ohm terminations. However,

1.76 dB must be subtracted from the dB scale for correct readings.

Figure 3-5. Setting the Frequency and Amplitude Controls (3 of 3)

3-14

Model 8640B

SETTING MODULATION

TM 9-4935-601-14-7&P

Amplitude Modulation

a. Set Meter Function (1) to AM.

b. To use the internal modulation oscillator, set AM (23) to INT. Set MODULATION FREQUENCY (18) to the desired frequency, and set percent of modulation with the MODULATION vernier (20); modulation is indicated by the meter (3) (e.g., a meter reading of 5.4 indicates that the AM is 54%).

NOTE

The REDUCE PEAK POWER annunciator (4) lights whenever the Signal Generator's output amplifier is being overdriven. When it lights, reduce MODULATION vernier or OUTPUT LEVEL vernier.

c. With AM (23) set to INT, the internal modulation oscillator signal is present at the AM OUTPUT jack (19) (600 ohm source impedance). Its level is set by AUDIO OUTPUT LEVEL (21)

Figure 3-6. Setting the Modulation Controls (1 of 4)

3-15

Model 8640B

SETTING MODULATION

TM 9-4935-601-14-7&P

d. To use an external modulation signal, set AM (23) to AC (or DC if modulation signal is less than 20 Hz). Apply the signal to the AM INPUT jack (19) (600 ohm load impedance). The Signal Generator requires 1 Vpk (0.7071

Vrms) for 100% modulation. Set percent of modulation with the MODULATION vernier (20) ; % AM is indicated by the meter (3).

NOTE

The meter reading is accurate when AM is set to DC only if no dc offset is applied to the AM

INPUT jack. The meter responds to the positive peak of the ac component of the modulating signal.

Pulse Modulation

a. Set Meter Function (1) to LEVEL.

b. Set AM (23) to PULSE (this disables the RF output). Apply the modulation pulse (>0.5V) to the AM INPUT jack

(19) (50 ohm load impedance). The Signal Generator requires a positive level to produce an RF output.

c. Set the desired pulse-on level using the OUTPUT LEVEL controls (10).

Figure 3-6. Setting the Modulation Controls (2 of 4)

3-16

Model 8640B TM 9-4935-601-14-7&P

SETTING MODULATION

Frequency Modulation

a. Set Meter Function (1) to FM.

b. To use the internal modulation oscillator, set FM (15) to INT. Set MODULATION FREQUENCY (18) to the desired frequency, and set the peak deviation with the PEAK DEVIATION switch and vernier (16).

NOTE

The REDUCE PEAK DEVIATION annunciator (4) lights whenever the PEAK DEVIATION switch setting is too high for the selected frequency range. When it lights, reduce PEAK DEVIATION.

c. Peak frequency deviation is indicated by the meter (3), and the meter is read in conjunction with the PEAK

DEVIATION switch (16) (e.g., with PEAK DEVIATION set to 320 kHz, a meter reading of 2.8 indicates that peak frequency deviation is 280 kHz).

d. With FM (15) set to INT, the internal modulation oscillator signal is present at the FM OUTPUT jack (17) (600 ohm source impedance). Its level is set by AUDIO OUTPUT LEVEL (21).

e. To use an external modulation signal, set FM (15) to AC (or DC if modulation signal is less than 20 Hz). Apply the signal to the FM INPUT jack (17) (600 ohm load impedance). The Signal Generator requires 1 Vpk (0.7071

Vrms) for full peak deviation. The PEAK DEVIATION controls (16) and the meter (3) are used the same as when using the internal modulation oscillator signal.

f. To calibrate the external input, set the FM switch (15) to DC (with no signal applied to FM input) and read the frequency of the RF Output. Set FM to CAL and, using the PEAK DEVIATION switch and vernier (16), offset the frequency at RF OUTPUT an amount equal to the desired peak deviation. Set FM to DC or AC; a 1 Vpk (0.7071

Vrms) signal applied to FM INPUT will now produce the desired peak deviation. (Do not use FM CAL when phase locked.)

Figure 3-6. Setting the Modulation Controls (3 of 4)

3-17

Model 8640B

SETTING MODULATION

TM 9-4935-601-14-7&P

NOTES

1. The REDUCE FM VERNIER annunciator (4) lights whenever an FM input causes peak deviation to exceed its limits. When it lights, reduce either the PEAK DEVIATION vernier or the external signal level.

2. Do not apply FM signals that are less than 50 Hz when using the generator in the phase lock mode. Doing so will cause either the FM deviation to be uncalibrated or the generator to break phase lock (thereby causing the counter display to flash). Also do not use FM CAL after locking.

Simultaneous AM and FM

a. Simultaneous AM and FM, or pulse modulation and FM, can be accomplished using the procedures described above. The internal modulation oscillator can be used for either one or both, AM and FM.

NOTE

On Signal Generators with the Option 001 Variable Modulation Oscillator, don't load both AM

OUTPUT (19) and FM OUTPUT (17) when the oscillator is providing both modulating signals.

The outputs are in parallel and the parallel load should be greater than 600 ohms.

Figure 3-6. Setting the Modulation Controls (4 of 4)

3-18

Model 8640B TM 9-4935-601-14-7&P

4-1. INTRODUCTION

4-2. The procedures in this section test the instrument's

electrical performance using the specifications of Table

1-1 as the performance standards. A simpler

operational test is included in Section III under

Operator's Checks.

4-3. EQUIPMENT REQUIRED

SECTION IV

PERFORMANCE TESTS

for the Model 8640B, are stated in general terms. For example, a test might require that a spectrum analyzer's resolution bandwidth be set to 100 Hz; however, the time per division setting would not be specified and the operator would set that control so that the analyzer operates correctly.

4-4. Equipment required for the performance tests is listed in the Recommended Test Equipment table in

Section I. Any equipment that satisfies the critical

specifications given in the table may be substituted for the recommended model(s).

4-5. TEST RECORD

4-9. It is also assumed that the person performing the tests will supply whatever cables, connectors, and adapters are necessary. The Test Accessories table in

Section I lists the requirements for some of these items.

4-10. Unless otherwise specified, set the following controls as shown:

TIME BASE INT/EXT (on rear panel) ........................INT

TIME BASE VERNIER .............................................CAL

4-6. Results of the performance tests may be tabulated on the Test Record at the end of the procedures. The

Test Record lists all of the tested specifications and their acceptable limits. Test results recorded at incoming inspection can be used for comparison in periodic maintenance and troubleshooting and after repairs or adjustments.

Use FINE TUNE in conjunction with FREQUENCY

TUNE to set whatever frequency is required. Use the

COUNTER MODE EXPAND controls whenever necessary to obtain required counter resolution.

4-7. TEST PROCEDURES

4-8. It is assumed that the person performing the following tests understands how to operate the specified test equipment. Equipment settings, other than those

CAUTION

To avoid the possibility of damage to test equipment, read completely through each test before starting it.

Make any preliminary control settings necessary for correct test equipment operation.

NOTE

Table 4-2 contains a list of recommended abridgments to the performance tests. The

abridgments suggest rapid and relatively inexpensive ways to test the instrument while retaining those tests which are considered of prime importance in characterizing the generator. Where alteration of a test is recommended, a justification (remark) is also given. Should individual needs make the justification invalid, the test should be performed in its entirety. (E.g., the

Incidental AM Test, sometimes known as AM on FM, has been omitted as being of secondary importance. Should your application require characterization of this specification, the test should be performed.)

4-1

Model 8640B TM 9-4935-601-14-7&P

PERFORMANCE TESTS

4-11. FREQUENCY RANGE TEST

SPECIFICATION:

Range: 500 kHz to 512 MHz in 10 octave bands.

Bands and Band Overlap: Bands extend 10% below and 7% above the nominal limits shown below.

Nominal

Frequency

Bands

(MHz)

0.5-1 1-2 2-4

Frequency

Range (MHz)

0.45

0.9

1.8

(with overlap) 1.07

2.1

4.2

4-8

3.6

8.5

8-16

7.2

17.1

16-32

14.4

34.3

32-64 64128256-

128 256 512

28.8

57.5

115 to

230 to

68.7

137.5

275 550

External

Doubler Band

512-1024

230 to 550

(without External Doubler)

DESCRIPTION:

The frequency range is verified by using a frequency counter to measure the frequency at the high and low end of each band.

EQUIPMENT:

Frequency Counter .....................................................................................HP 5327C

PROCEDURE:

Connect generator's auxiliary RF output jack (located on rear panel) to frequency counter's 50 ohm input after setting Signal Generator's controls as follows:

COUNTER MODE: EXPAND ................................................................................... Off

LOCK........................................................................................ Off

Source ..................................................................................... INT

AM............................................................................................................................................................ OFF

FM............................................................................................................................................................ OFF

RANGE ...................................................................................................................................... 256-512 MHz

FREQUENCY TUNE ................................................................................................................. Full clockwise

FINE TUNE .......................................................................................................................................Centered

RF ON/OFF................................................................................................................................................ON

Set FREQUENCY TUNE full clockwise. The frequency counter should read 550 MHz or greater.

550.0 MHz _______________________

4-2

Model 8640B TM 9-4935-601-14-7&P

PERFORMANCE TESTS

4-11. FREQUENCY RANGE TEST (Cont'd)

Set FREQUENCY TUNE full counterclockwise. The frequency counter should read 230 MHz or less.

_______________________ 230.0 MHz

Set RANGE as shown below and check frequency at high and low ends of each band.

Range (MHz)

512-1024*

128-256

64-128

32-64

16-32

8-16

4-8

2-4

Low End

_______________<230.0 MHz

_______________<115.0 MHz

_______________<57.50 MHz

_______________<28.80 MHz

_______________<14.40 MHz

_______________<7.200 MHz

_______________<3.600 MHz

_______________<1.800 MHz

1-2

0.5-1

*No external doubler should be connected.

_______________<0.900 MHz

_______________<0.450 MHz

High End

>550.0 MHz ______________

>275.0 MHz ______________

>137.5 MHz ______________

>68.70 MHz ______________

>34.30 MHz ______________

>17.10 MHz ______________

>8.500 MHz ______________

>4.200 MHz ______________

>2.100 MHz ______________

>1.070 MHz ______________

4-12. FREQUENCY ACCURACY AND FINE TUNE TEST

SPECIFICATION:

Accuracy: [ Total

Count

Accuracy

]

[ Counter

Resolution

(±1 count)

]

[

Reference

Error

(INT or EXT)

]

35°C).

Internal Reference Error: <+2 ppm (when calibrated at 25°C every 3 months and operated between 15°C and

When phase locked, Counter Resolution error is eliminated.

Fine Tuning: Unlocked, >200 ppm total range. Locked mode, >±20 ppm by varying internal time base vernier.

4-3

Model 8640B TM 9-4935-601-14-7&P

PERFORMANCE TESTS

4-12. FREQUENCY ACCURACY AND FINE TUNE TEST (Cont'd)

DESCRIPTION:

Frequency accuracy is checked (using the Signal Generator's internal reference) by comparing the generator's counter indication to the frequency reading on an external frequency counter. The fine tune range is also checked with the external counter.

EQUIPMENT:

Frequency Counter ................................................................................... HP 5327C OPT H49

PROCEDURE:

Connect generator's auxiliary RF output jack (located on rear panel) to frequency counter's input after setting

Signal Generator's controls as follows:

COUNTER MODE: EXPAND ................................................................................ X100

LOCK........................................................................................ Off

Source ..................................................................................... INT

AM............................................................................................................................................................ OFF

FM............................................................................................................................................................ OFF

RANGE .......................................................................................................................................... 32-64 MHz

FREQUENCY TUNE ........................................................................................................................... 50 MHz

RF ON/OFF................................................................................................................................................ON

Allow Signal Generator and frequency counter to stabilize for two hours.

Set frequency counter time base to give at least one more digit resolution than the generator's counter. The difference in reading between the two counters should be <110 Hz (2 ppm + last digit uncertainty of 10 Hz).

__________________________ 110 Hz

Set COUNTER MODE EXPAND to X10 and LOCK to ON. Allow one minute to acquire phase lock. Increase the frequency counter resolution by 10. The difference in counter readings should be <100 Hz (2 ppm).

__________________________ 100 Hz

Note frequency counter reading. Turn TIME BASE VERN control ccw until it just leaves the detent position. The frequency counter should now read >1 kHz (>20 ppm) higher than the reading noted above.

1 kHz ___________________________

Turn TIME BASE VERN fully ccw. The frequency counter should now read >1 kHz (>20 ppm) lower than the reading first noted in step 5.

1 kHz ___________________________

4-4

Model 8640B TM 9-4935-601-14-7&P

PERFORMANCE TESTS

4-12. FREQUENCY ACCURACY AND FINE TUNE TEST (Cont'd)

Set TIME BASE VERN to CAL (fully cw). Set COUNTER MODE LOCK to Off.

Set FINE TUNE fully cw. Note frequency counter reading, then set FINE TUNE fully ccw. The frequency counter should read >10 kHz (200 ppm) lower than the reading noted above.

10 kHz __________________________

4-13. FREQUENCY STABILITY VS TIME AND RESTABILIZATION TIME TEST

SPECIFICATION:

Stability vs Time (after 2 hour warmup): <10 ppm/10 min. (normal mode).

Restabilization Time (normal mode):

After frequency change: <15 min.

After band change: none.

After 1 min. in RF OFF mode: <10 min.

NOTE

Stability specifications for phase lock mode are determined by counter time base reference. See the internal reference tests.

DESCRIPTION:

A frequency counter, digital to analog converter, and strip-chart recorder are used to measure the frequency drift after warm-up and the restabilization time.

NOTE

For these tests, ambient room temperature and line voltage must not change.

Figure 4-1. Frequency Stability us Time and Restabilization Time Test Setup

4-5

Model 8640B TM 9-4935-601-14-7&P

PERFORMANCE TESTS

4-13. FREQUENCY STABILITY VS TIME AND RESTABILIZATION TIME TEST (Cont'd)

EQUIPMENT:

Frequency Counter ................................................................................... HP 5327C OPT 003

Digital to Analog Converter ..........................................................................HP 581A OPT 002

Recorder (for D/A Converter) ........................................................................................ HP 680

PROCEDURE:

Connect equipment as shown in Figure 4-1 after setting Signal Generator's controls as follows: