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8672A Synthesized Signal Generator Operating and Service Manual
08672-90086
September 1987

OPERATING AND SERVICE MANUAL-
HP 8672A
SYNTHESIZEDSIGNAL GENERATOR
(Including Options
001,002,003,
004,005,034, and 038)
SERIAL NUMBERS
This manual applies directly to instruments with
serial numbers prefixed 2229A.
With changes described in Section VII, this man¬
ual also applies to instruments with serial num¬
bers prefixed 1610A, 1701A thru 1708A, 1711A,
1712A, 1719A, 1725A, 1731A thru 1733A, 1801A,
1816A, 1821A, 1822A, 1831A, 1833A, 1834A,
1841A, 1845A, 1905A, 1906A, 1913A, 1914A,
1930A, 1940A, 2002A, 2005A thru 2008A, 2010A,
2012A, 2014A, 2016A, 2017A, 2018A, 2019A,
2020A, 2034A, 2037A, 2039A, 2040A, 2101A,
2102A, 2103A, 2104A, 2105A, 2114A, 2115A,
2126A, 2132A, 2133A, 2207A, 2208A, 2210A,
2211A, 2220A, and 2221A.
For additional important information about serial
numbers, see INSTRUMENTS COVERED BY
MANUAL in Section I.
HEWLETT
PACKARD
© Copyright HEWLETT-PACKARD COMPANY 1977, 1978,1980,1983
1501 PAGE MILL ROAD, PALO ALTO, CALIFORNIA, U.S.A.
OPERATING AND SERVICE MANUAL PART NO. 08672-90086
Operating Manual Part No. 08672-90087
Operating and Service Microfiche Part No. 08672-90088 Printed: September 1987

Contents Model 8672A
CONTENTS
Section
I GENERAL INFORMATION . .
1-1. Introduction .............
1-7. Specifications ............
1-9. Safety Considerations .......
1-13. Instruments Covered by Manual
1-17. Manual Change Supplements . . .
1-20. Description ..............
1-22.
1-25.
1-28.
1-32.
Frequency .................
Output Level ...............
Modulation Modes ...........
Miscellaneous Outputs and
Indicators ...............
1-37. Remote Operation ...........
1-40. Options ....................
1-41. Electrical Options ............
1-47. Mechanical Options ...........
1-53. Compatibility ................
1-56. Selecting the HP-IB Address .......
1-58. Accessories supplied ............
1-60. Equipment Required but Not Supplied
1-64. Equipment Available ............
1-69. Recommended Test Equipment .....
II INSTALLATION ............
2-1. Introduction ...............
2-3. Initial Inspection ............
2-5. Preparation for Use ...........
2-6. Power Requirements ........
2-8. Line Voltage and Fuse Selection
2-10. Power Cable .............
2-12. HP-IB Address and Parallel Poll
Response Selection .......
2-15. Interconnections ..........
2-17. Mating Connectors .........
2-20. Operating Environment ......
2-22. Bench Operation ..........
2-24. Rack Mounting ...........
2-26. Storage and Shipment .........
2-27. Environment .............
2-29. Packaging ...............
OPERATION ................
Ill
3-1.
3-4.
3-6.
3-8.
Introduction ................
Panel Features ...............
Operator's Maintenance .........
Mechanical Meter Zeroing . . . . .
3-10. Local Operation ..............
3-12. Local Operator's Check .........
3-14. Local Operating Instructions ......
3-16. Remote (HP-IB) Operation .......
3-20. Compatibility .............
3-23. Local/Remote and Remote/Local
Mode Changes ...........
Page
. 1-1
1-1
1-1 .
1-1
.
1-1 . 1-1
1-5
. 1-5
1-5
1-5
1-6 .
1-6
.
1-6 . 1-6
1-6
. 1-6
1-7
1-7 .
1-7 .
1-7 . 1-7
. 2-1
2-1
. 2-1
2-1
2-1 .
2-1
.
2-2
.
2-2 . 2-3
2-3
. 2-3
2-3
2-5 .
2-5
.
2-5 . 2-6
. 3-1
3-1
. 3-1
3-1
3-1 .
3-1
.
3-1 . 3-1
3-13
3-13
3-13 Section
3-28.
3-30.
3-40.
3-42.
3-44.
3-46.
3-48.
3-50.
3-52.
3-54.
3-56.
3-58.
3-62.
3-64.
3-66.
3-68.
Data
Messages
................
Receiving
Data Messages ......... Sending
Data Messages ........... Receiving
the Trigger Message ...... Receiving
the Clear Message ....... Receiving
the RemoteMessage ..... Receiving
the Local Message ....... Receiving
the Local Lockout Message . Receiving
the Clear Lockout/Set Local Message
.................. Receiving the
Pass Control Message . . Sending
the Require Service Message . Sending
the Status Byte Message .... Sending
the Status Bit Message ..... Receiving
the Abort Message ....... Programming
Quick Reference Guide . Programming
Examples .......... IV PERFORMANCE
TESTS ............... 4-1.
Introduction .......................
4-3. Equipment Required ..................
4-5. Test Record ........................
4-7. Calibration Cycle ....................
4-9. Abbreviated Performance Testing .........
4-11. Operational Verification Checks ..........
4-12. Output Level Flatness .................
4-13. Harmonics and Subharmonics ............
4-14.SWR ............................ 4-15.
FM Accuracy .......................
4-16. AM Distortion ......................
4-17. Amplitude Modulation Depth, Meter Accuracy
and Input Accuracy ................ 4-18.
Non-Harmonically Related Spurious (CW
and AM Modes) ............... 4-19. Power
Line Related Spurious (CW and
AM Modes) ..................... 4-20. Single-Sideband
Phase Noise Ratio .........
4-21. FM Frequency Response ..............
4-22. FM Harmonic and Non-Harmonic Distortion
. 4-23. Residual FM In FM and CW
Modes .......
4-24. RF Output Level and Accuracy ..........
4-25. Incidental Phase and Frequency Modulation
. 4-26. Frequency Switching Time .............
4-27. Output Level Switching Time ...........
4-28. AM Rates ........................ 4-29.
Incidental AM .....................
4-30. Internal Time Base Aging Rate ..........
ADJUSTMENT .... 5-1. Introduction ......
5-5. Safety Considerations
5-7. Equipment
Required . Page 3-13 3-13
3-19 3-19 3-19 3-19 3-19
3-19
3-19
3-19
3-19
3-19
3-20
3-20
3-20
3-20
.
4-1
4-1
. 4-1
. 4-1
.
4-1 .
4-1
4-2
. 4-4
. 4-5
. 4-7
4-10
4-11 4-15
4-19
4-20
4-22
4-25
4-27 4-29
4-31
4-35
4-37
4-39
4-42
4-43
4-44
5-1
5-1
5-1
5-1

Model 8672A
Section
CONTENTS (Cont'd)
Page Section
5-11. Factory Selected Components ...........
5-13. Related Adjustments .................
5-18. Adjustment Locations ................
5-20. A3 RF Source Assembly Adjustments ......
5-21. Power Supply Adjustments ...........
5-22. 10 MHz Reference Oscillator Adjustment .
5-23. Digital-to-Analog Converter Adjustment . .
5-24. YTO Driver Adjustment .............
5-25. Voltage Controlled Crystal Oscillator
(VCXO) Adjustment .............
5-26. M/N Loop Adjustments .............
5-27. YTO Loop Sampler Adjustments .......
5-28. YTO Loop Offset and FM Overmodulation
Adjustments ..................
5-29. YTO Loop Phase Detector Adjustment . . .
5-30. FM Driver Adjustment ..............
5-31. A2 Controller Assembly Adjustments ......
5-32. 160-240 MHz (20/30 MHz or LFS Loop)
VCO Pretune Adjustments .........
5-33. 20/30 MHz (LFS) Loop Divider Bias
Adjustments ..................
5-34. A2A4 Assembly Notch Filter Adjustment .
5-35. Al RF Output Assembly Adjustments .....
5-36. YTM Adjustments ................
5-37. ALC Adjustments .................
5-38. External Leveling Adjustments ........
5-39. AM Bandwidth Adjustment ..........
5-40. AM Meter Adjustment ..............
5-41. AM Meter Adjustment — Alternate
Procedure ....................
5-42. FM Adjustments ..................
VI REPLACEABLE PARTS ..............
6-1. Introduction ......................
. 5-1
. 5-1
. 5-2
. 5-6
. 5-6
. 5-7
. 5-8
. 5-9
5-10
5-12
5-14
5-17
5-19
5-21
5-22
5-22
5-23
5-24
5-25
5-25
5-29
5-32
5-34
5-35
5-36
5-37
6-2. Exchange Assemblies ....
6-3. Abbreviations ...........
6-4. Replaceable Parts List ....
6-5. Parts List Updating ......
6-6. Illustrated Parts Breakdown
6-7. Ordering Information ....
6-8. Recommended Spares List
VII MANUAL CHANGES
7-1. Introduction ......
7-3. Manual Changes ....
VIII SERVICE ...................
8-1. Introduction .................
8-5. Safety Considerations ...........
8-11. Principles of Operation ..........
8-13. Troubleshooting ...............
8-14. Arrangement in Manual ........
8-16. Supplemental Troubleshooting Aids
8-20. Recommended Test Equipment.....
8-22. Service Aids ..................
8-27. Repair .....................
8-29.
8-31.
8-33.
8-35.
8-41.
8-59. Logic Symbols ........
8-61. Qualifiers .........
8-63. Indicator Symbols . . .
8-65. Contiguous Blocks . . .
8-67. Dependency Notation .
8-69. Common Control Block
8-71. Complex Devices ....
Factory Selected Components........
Non-Field Repairable Assemblies .....
Module Exchange Program ..........
After Service Product Safety Checks . . .
Disassembly and Reassembly Procedures .
6-1
6-1
SERVICE SHEETS
Service Sheet
Overall Functional Block Diagram ......
A3 RF Source Assembly Troubleshooting .
A2 Controller Troubleshooting ........
Al RF Output Assembly Troubleshooting .
1-A1 RF Preamplifier and P/0 ALC Loop
(A1A5, A1A13, A1AT3) ..........
2-A1 YTM Control (A1A8, A1A3, A1A12,
A1AT2,A1FL1) ...............
3-A1 SRD Control (A1A7) ..............
4-A1 P/0 ALC Loop (A1A6, A1CR1, A1DC1) .
Page Service Sheet
8-33 5-A1 RF Output Level Control (A1A10, A1AT1)
8-34 6-A1 Digital Control (A1A11) .............
8-38 7-A1 Front Panel Controls and Displays (A1A1,
8-40 A1A2) ......................
8-A1 Metering Control (A1A9) ............
8-42 1-A2 20/30 MHz Divider (A2A5) ..........
2-A2 Phase Detector (A2A4) ..............
8-44 3-A2 VCO 160-240 MHz (A2A3) ...........
8-46 4-A2 HP-IB Address (A2A9) .............
8-48 5-A2 P/0 HP-IB Interface (P/0 A2A7) .......

Contents Model 8672A
SERVICE SHEETS (Cont'd)
Service Sheet Page
6-A2 P/0 HP-IB Interface (P/0 A2A7) ......... 8-68
7-A2 Register 1 (A2A10) .................. 8-70
8-A2 P/0 Timing and Control (P/0 A2A11) ..... 8-72
9-A2 P/0 Timing and Control (P/0 A2A11) ..... 8-74
10-A2 P/0 Output Register (P/0 A2A8) ........ 8-76
11-A2 P/0 Output Register (P/0 A2A8) ........ 8-78
12-A2 P/0 Front Panel (P/0 A2A1) ........... 8-80
13-A2 P/0 Front Panel (P/0 A2A1, A2A2) ...... 8-82
1-A3 Reference Phase Lock (A3A1A1, A3A8) .... 8-84
2-A3 100 MHz VCXO (A3A1A2) ............ 8-86
3-A3 M/N Phase Detector (A3A1A3) .......... 8-88
4-A3 M/N VCO (A3A1A4) ................ 8-90
5-A3 M/N Output (A3A1A5) ............... 8-92
6-A3 Digital-to-Analog Converter (A3A5) ....... 8-94
7-A3 YTO Main Coil Driver (A3A6) .......... 8-96
8-A3 YTO Sampler (A3A9A5, A3A9U1) ....... 8-98
9-A3 YTO Phase Detector (A3A9A2, A3A9A4) . . 8-100
Service Sheet Page
10-A3 FM Driver (A3A7, A3A9A1, A3A9A3,
A3A9A6, A3A9A7) ................ 8-102
11-A3 Rectifier Board (A3A2, A3A11) ........ 8-104
12-A3 Positive Regulator Board (A3A3) ........ 8-106
13-A3 Negative Regulator Board (A3A4) ....... 8-108
Al RF Output Assembly Interconnections,
and A1A14 Motherboard ............ 8-110
A2 Controller Assembly Interconnections
and A2A12 Motherboard ............ 8-113
A3A10 Mother Board Interconnections,
A3A1A6 Reference and M/N Mother
Board, and A3 Plug-in Circuit Board ..... 8-115
A3A9 Assembly and Cable Locations,
8672A Bottom View ............... 8-117
8672A Top Views .................. 8-119
Al, A2, and A3 Top Views of Adjustments
and Test Point Locations ............ 8-121
LIST OF ILLUSTRATIONS
2-1.
2-2.
2-3.
2-4.
3-1.
k
3-2.
3-3.
3-4.
3-5.
3-6.
3-7.
4-1.
4-2.
4-3.
4-4.
4-5.
Figure
1-1. HP Model 8672A and Accessories Supplied
1-2. 15 kHz Low Pass Filter .............
1-3. Special Interconnect Cable ...........
Line Voltage and Fuse Selection ........
Power Cable and Mains Plug Part Numbers .
Location of HP-IB Address and Parallel Poll
Switches .......................
Hewlett-Packard Interface Bus Connection .
Front Panel Connectors, Controls, Switches,
and Displays ....................
Rear Panel Connectors, Switches, and
Displays .......................
Operator's Frequency and Modulation
Checks Test Setup ................
Operator's External ALC Checks Test Setup
Frequency Programming .............
Typical frequency switching time showing
WORST CASE lock and settling times . . .
Programming Examples ..............
Typical Maximum Power Available on the
+10 dBm Range (over-range) ...........
SWR Test Setup ....................
FM Accuracy Test Setup ..............
AM Distortion Test Setup .............
Amplitude Modulation Depth Meter Accuracy
and Input Accuracy Test Setup .........
Page
. 1-0
1-10
1-10
. 2-1
. 2-2
. 2-3
. 2-4
3-2
. 3-4
. 3-6
. 3-8
3-16
3-18
3-22
. 4-2
. 4-7
4-10
4-11
.4-15
Figure Page
4-6. Power Line Related Spurious Test Setup ..... 4-21
4-7. Single-Sideband Phase Noise Ratio
Test Setup ........................ 4-23
4-8. FM Frequency Response Test Setup ........ 4-25
4-9. FM Distortion Test Setup ............... 4-27
4-10. Residual FM in FM and CW Modes
Test Setup ........................ 4-29
4-11. RF Output Level and Accuracy
Test Setup ........................ 4-32
4-12. Incidental Phase and Frequency Modulation
Test Setup ........................ 4-35
4-13. Frequency Switching Time Test Setup ...... 4-37
4-14. Output Level Switching Time Test
Setup ........................... 4-40
4-15. AM Rate Test Setup .................. 4-42
4-16. Incidental AM Test Setup ............... 4-43
4-17. Internal Time Base Aging Rate Test Setup .... 4-44
5-1. 10 MHz Reference Oscillator Adjustment
Test Setup ......................... 5-7
5-2. VCXO Adjustment Test Setup ........... 5-10
5-3. M/N Loop Adjustment Test Setup ......... 5-13
5-4. YTO Loop Sampler Adjustment Test
Setup ........................... 5-15
5-5. Typical Swept Frequency Response at
A3A9A5TP1 (frequency span per division
20 MHz) ......................... 5-16
5-6. YTO Loop Offset and FM Overmodulation
Test Setup ........................ 5-17
IV

Model 8672A
Figure
ILLUSTRATIONS (Cont'd)
Page Figure
5-7. YTO Loop Offset Adjustment Waveforms .
5-8. YTO Loop Phase Detector Adjustment
Test Setup .....................
5-9. Spectrum Analyzer Display of Phase
Locked-Loop Gain ...............
5-10. FM Driver Adjustment Test Setup ......
5-11. 20/30 MHz Loop Divider Bias Adjustment
Test Setup .....................
5-12. A2A4 Assembly Notch Filter Adjustment
Test Setup .....................
5-13. YTM Adjustment Test Setup .........
5-14. Typical YTM Response .............
5-15. AM Meter Adjustment Test Setup ......
5-16. FM Adjustment Test Setup ...........
6-1. Al and A2 Assembly Front Panel
Mechanical Parts...........
6-2. Synthesizer Cabinet Parts ......
7-1. A1A6 ALC Detector Assembly Component,
Adjustment, and Test Point Locations
(P/0 Change S)...................
P/0 ALC Loop Schematic (P/0 Change S). . .
7-2.
7-3. P/0 A2A11 Timing and Control Assembly
Component, Adjustment, and Test Point
Locations (P/0 Change T)............
P/0 A2A11 Timing and Control Assembly
Component and Test Point Locations
(P/0 Change T). ..................
7-4
P/0 Timing and Control Assembly Schematic
Diagram (P/0 Change T).............
7-5
7-6.
7-7.
Cable Connections (P/0 Change Z) .........
A1A6 ALC Detector Assembly Component,
Adjustment, and Test Point Locations
(P/0 Change AD) ..................
A1A3A1 YTM Assembly Component,
Adjustment, and Test Point Locations
(P/0 Change AK) ..................
7-8.
P/0 Digital Control Schematic Diagram
7-9 (P/0 Change AW) ..................
7-10. P/0 Register 1 Assembly Schematic Diagram
(P/0 Change AW) ..................
5-18
5-19
5-20
5-21
5-23
5-24
5-26
5-28
5-35
5-37
6-19
6-63
7-10
7-10
7-12
7-13
7-14
7-17
7-18
7-21
7-26
7-27
8-1.
8-2.
8-3.
8-4.
8-5.
8-6.
8-7.
Schematic Diagram Notes ............
Rear Panel of the Synthesizer .........
Al and A2 Assembly Front Panel Fully
Extended .....................Bottom of the Synthesizer ......
A3A9 Assembly in Service Position . ...
Qualifiers .................. ...
Contiguous Blocks ................
8-2
8-7
8-8
8-10
8-11
8-14
8-15
8-8. Indicator Symbols ...................
8-9. AND Dependency Notation .............
8-10. OR and Free Dependency Notation ........
8-11. AND Dependency Notation, Coder
Example Using Letters ................
8-12. Common Control Block ................
8-13. Quad D-Type Latch (Individual) ..........
8-14. Quad D-Type Latch (Combined) ..........
8-15. Quad D-Type Latch Example ............
8-16. Multiplexer (AND-OR Selected) Example ....
8-17. Shift Register Example ................
8-18. Up-Down Counter Example .............
8-19. Synthesizer's Simplified Block Diagram .....
8-20. Major Assembly Locations ..............
8-21. Overall Functional Block Diagram .........
8-22. A3 RF Source Assembly Troubleshooting
Block Diagram .....................
8-23. A2 Controller Troubleshooting Block
Diagram .........................
8-24. Al RF Output Assembly Troubleshooting
Block Diagram .....................
8-25. A1A5 ALC Assembly Component, Adjustment
and Test Point Locations ..............
8-26. RF Preamplifier and P/0 ALC Loop
Block Diagrams ....................
8-27. RF Preamplifier and P/0 ALC Loop
Schematic ........................
8-28. A1A3 YTM Assembly Component,
Adjustment, and Test Point Locations .....
8-29. A1A8 YTM Driver Assembly Component
Adjustment, and Test Point Locations .....
8-30. YTM Control Block Diagrams ............
8-31. YTM Control Schematic Diagram .........
8-32. A1A7 SRD Bias Assembly Component,
Adjustment, and Test Point Locations .....
8-33. SRD Control Block Diagrams ............
8-34. SRD Control Schematic Diagram ..........
8-35. A1A6 ALC Detector Assembly Component,
Adjustment, and Test Point Locations .....
8-36. P/0 ALC Loop Block Diagrams ...........
8-37. P/0 ALC Loop Schematic ..............
8-38. A1A10 Level Control Assembly Component,
Adjustment, and Test Point Locations .....
8-39. RF Output Level Control Block Diagrams ....
8-40. RF Output Level Control Schematic
Diagram .........................
8-41. A1A11 Digital Processor Assembly Component,
Adjustment, and Test Point Locations .....
8-42. Digital Control Block Diagrams ...........
8-43. Digital Control Schematic Diagram ........
8-44. A1A2 Display Driver Assembly Component
Locations ........................

Contents Model 8672A
Figure
ILLUSTRATIONS (Cont'd)
Page Figure Page
8-45. A1A2 Front Panel Assembly Component, 8-75.
Switches, and Test Point Locations ....... 8-54
8-46. Front Panel Controls and Displays Block 8-76.
Diagrams ......................... 8-55 8-77.
8-47. Front Panel Controls and Displays
Schematic Diagram .................. 8-55 8-78.
8-48. A1A9 Metering Assembly Component,
Adjustment, and Test Point Locations ..... 8-56 8-79.
8-49. Metering Control Block Diagrams ......... 8-57 8-80.
8-50. Metering Control Schematic Diagram ....... 8-57
8-51. A2A5 20/30 MHz Divider Assembly 8-81.
Component, Adjustment, and Test
Point Locations .................... 8-58 8-82.
8-52. 20/30 MHz Divider Block Diagrams ........ 8-59 8-83.
8-53. 20/30 MHz Divider Assembly Schematic
Diagram ......................... 8-59 8-84.
8-54. A2A4 20/30 Phase Detector Assembly
Component, Adjustment, and Test Point 8-85.
Locations ........................ 8-60 8-86.
8-55. 20/30 MHz Phase Detector Block
Diagrams ......................... 8-61 8-87.
8-56. 20/30 MHz Phase Detector Assembly
Schematic ........................ 8-61 8-88.
8-57. A2A3 160—240 MHz Assembly Component 8-89.
Locations ........................ 8-62
8-58. VCO 160-240 MHz Block Diagrams ...... 8-63 8-90.
8-59. VCO 160—240 MHz Assembly Schematic
Diagram ........................ 8-63
8-60. A2A9 HP-IB Address Assembly Component 8-91.
Locations ....................... 8-64 8-92.
8-61. HP-IB Address Block Diagrams .......... 8-65
8-62. HP-IB Address Assembly Schematic 8-93.
Diagram ........................ 8-65
8-63. P/0 A2A7 Interface Assembly Component
and Test Point Locations ............. 8-66 8-94.
8-64. P/0 Interface Block Diagrams ........... 8-67 8-95.
8-65. P/0 HP-IB Interface Assembly Schematic
Diagram ........................ 8-67 8-96.
8-66. P/0 A2A7 Interface Assembly Component
Locations ....................... 8-68 8-97.
8-67. P/0 Interface Block Diagrams ........... 8-69 8-98.
8-68. P/0 Interface Assembly Schematic Diagram . . 8-69
8-69. A2A10 Register 1 Assembly Component 8-99.
Locations ....................... 8-70
8-70. Register 1 Block Diagrams ............. 8-71
8-71. Register 1 Assembly Schematic Diagram .... 8-71 8-100,
8-72. P/0 A2A11 Timing and Control Assembly 8-101,
Component, Adjustment, and Test Point 8-102,
Locations ....................... 8-72
8-73. P/0 Timing and Control Block Diagrams .... 8-73 8-103
8-74. P/0 Timing and Control Schematic Diagram . 8-73 8-104
P/0 A2A11 Timing and Control Assembly
Component and Test Point Locations ..... 8-74
P/0 Timing and Control Block Diagrams .... 8-75
P/0 Timing and Control Assembly
Schematic Diagram ................. 8-75
P/0 A2A8 Output Register Assembly
Component and Test Point Locations ..... 8-76
P/0 Output Register Block Diagrams ...... 8-77
P/0 Output Register Assembly Schematic
Diagram ........................ 8-77
P/0 A2A8 Output Register Assembly
Component and Test Point Locations ..... 8-78
P/0 Output Register Block Diagrams ...... 8-79
P/0 Output Register Assembly Schematic
Diagram ........................ 8-79
P/0 A2A1 Front Panel Assembly Component
Locations ....................... 8-80
P/0 Front Panel Block Diagrams ......... 8-81
P/0 Front Panel Assembly Schematic
Diagram ........................ 8-81
P/0 A2A1 Front Panel Assembly Component
Locations ....................... 8-82
P/0 Front Panel Block Diagrams ......... 8-83
P/0 Front Panel Assembly Schematic
Diagram ........................ 8-83
A3A1A1 Reference Phase Lock Board
Assembly Component and Test Point
Locations ....................... 8-84
Reference Phase Lock Block Diagrams ..... 8-85
Reference Phase Lock Assembly Schematic
Diagram ......................... 8-85
A3A1A2 100 MHz VCXO Assembly
Component, Adjustment, and Test
Point Locations ................... 8-86
100 MHz VCXO Block Diagrams ......... 8-87
100 MHz VCXO Assemlby Schematic
Diagram ........................ 8-87
A3A1A3 M/N Phase Detector Assembly
Component and Test Point Locations ..... 8-88
M/N Phase Detector Block Diagrams ...... 8-89
M/N Phase Detector Assembly Schematic
Diagram ........................ 8-89
A3A1A4A2 M/N VCO Board Assembly
Component, Adjustment, and Test Point
Locations ....................... 8-90
M/N VCO Block Diagrams ............. 8-91
M/N VCO Assembly Schematic Diagram .... 8-91
A3A1A5 M/N Output Assembly
Component Locations ............... 8-92
M/N Output Block Diagrams ............ 8-93
M/N Output Assembly Schematic Diagram . . 8-93
VI

Model 8672A
Figure
8-105. A3A5 DAC Assembly Component,
Adjustment, and Test Point Locations .... 8-94
8-106. Digital-to-Analog Converter Block
Diagrams ........................ 8-95
8-107. Digital-to-Analog Converter Schematic
Diagram ........................ 8-95
8-108. A3A6 YTO Main Coil Driver Assembly
Component, Adjustment, and Test Point
Locations ....................... 8-96
8-109. YTO Main Coil Driver Block Diagrams ..... 8-97
8-110. YTO Main Coil Driver Schematic Diagram . . . 8-97
8-111. A3A9A5 YTO Sampler Assembly
Component, Adjustment, and Test
Point Locations ................... 8-98
8-112. YTO Sampler Block Diagrams ........... 8-99
8-113. YTO Sampler Assembly Schematic
Diagrams........................ 8-99
8-114. A3A9A4 YTO Phase Detector Assembly
Component, Adjustment, and Test
Point Locations .................. 8-100
8-115. YTO Phase Detector Block Diagrams ..... 8-101
8-116. YTO Phase Detector Schematic Diagram . . . 8-101
8-117. A3A7 FM Driver Assembly Component
Adjustment, and Test Point Locations . . . 8-102
8-118. FM Driver Block Diagrams ............ 8-103
8-119. FM Driver Assembly Schematic Diagram . . . 8-103
8-120. A3A2 Rectifier Assembly Component,
Adjustment and Test Point Locations .... 8-104
8-121. Rectifier Block Diagrams ............. 8-105
8-122. Rectifier Board Assembly Schematic
Diagram ....................... 8-105
8-123. A3A3 Positive Regulator Assembly
Component, Adjustment, and Test
Point Locations .................. 8-106
8-124. Positive Regulator Block Diagrams ....... 8-107
8-125. Positive Regulator Board Assembly
Schematic Diagram ................ 8-107
ILLUSTRATIONS (Cont'd)
Page Figure
8-126. A3A4 Negative Regulator Assembly
Component and Test Point Locations . . .
8-127. Negative Regulator Block Diagrams .....
8-128. Negative Regulator Board Assembly
Schematic Diagram ...............
8-129. Remote Operator's Checks Test
Setup ........................
8-130. Major Assembly Locations ...........
8-131. Al to A2 Interconnections ...........
8-132. A1A14 Mother Board Assembly Connector
Locations .....................
8-133.
8-134.
8-135.
8-136.
8-137.
8-138.
8-139.
8-140.
8-141.
8-142.
8-143.
8-144.
8-145.
8-146.
8-147.
Major Assembly Locations ............
A2A12 Mother Board Assembly Component
Locations ......................
A3A10 RF Source Mother Board
Component Locations ..............
A3A1A6 Reference and M/N Mother Board
Assembly Component and Connector
Locations ......................A3 Plug-in Circuit Board Adjustment and
Test Point Locations ...............
A3A9 Assembly Locations ............
A3A9 Cable Connections .............
Major Assembly Locations ............
Bottom View Assembly Locations .......
Major Assembly Locations ............
Top View Assembly Locations .........
Top View Chassis Mounted Parts,
Assembly Locations ...............
Major Assembly Locations ............
Top View A2 and A3 Assemblies Adjust¬
ments and Test Point Locations ........
Top View Al Assembly Adjustment
Locations ......................

Contents Model 8672A
Table
1-1.
1-2.
2-1.
3-1.
3-2.
3-3.
3-4.
3-5.
3-6.
3-7.
3-8.
3-9.
3-10.
4-1.
4-2.
4-3.
4-4.
5-1.
Specifications .....................
Recommended Test Equipment ..........
USA Standard Code for Information
Interchange (ASCII) ................
Front Panel Features .................
Rear Panel Features .................
Local Operator's Checks ..............
Local Operating Instructions ............
Message Reference Table ..............
Frequency Program Codes and Arguments . . .
Output Level ......................
Modulation .......................
ALC Arguments (with RF ON) ..........
Programming Quick Reference Guide ......
Record of Operational Verification Checks . .
Harmonic Level versus Percentage Distortion .
Modulation Index ...................
Factory Selected Components ...........
TABI
Page
. . 1-2
. . 1-8
. . 2-5
30
. . 3-4
. . 3-5
. . 3-9
. 3-14
. 3-15
. 3-17 .
. 3-17
117
. 3-21
. . 4-4
. 4-14
. 4-16
. 4-46
. . 5-2
LES
Table
5-2.
5-3.
6-1.
6-2.
6-3.
6-4.
7-1.
7-2.
8-1.
8-2.
8-3.
8-4.
8-5.
8-6.
8-7.
8-8.
Performance Test Failure and Required
Action .........................
Related Adjustments .................
Part Numbers for Exchange Assemblies .....
Reference Designations and Abbreviations . . .
Replaceable Parts ...................
Manual Changes by Serial Number Prefix . . .
Summary of Changes by Component ......
HP-IB Diagnostic Program .............
Front Panel Status Annunciators .........
Overall Troubleshooting ...............
Listing of all M and N Numbers and
Resulting Frequencies ................
Remote Operator's Check .............
RF Output Assembly (Al) Inteconnections . .
Controller Assembly (A2) Interconnections . .
Motherboard Assembly (A3A10)
Interconnections ..................
Page
. . 5-3
. . 5-4
60
. . 6-3
. . 6-5
. 6-65
. . 7-1
. . 7-2
8-20
8-30
8-31
. 8.35
8-110
8-111
8-113
8-115
V111

Model 8672A Safety Considerations
SAFETY CONSIDERATIONS
GENERAL
This product and related documentation must be
reviewed for familiarization with safety markings
and instructions before operation.
This product is a Safety Class I instrument (pro¬
vided with a protective earth terminal).
BEFORE APPLYING POWER
Verify that the product is set to match the avail¬
able line voltage and the correct fuse is installed.
SAFETY EARTH GROUND
An uninterruptible safety earth ground must be
provided from the main power source to the pro¬
duct input wiring terminals, power cord, or sup¬
plied power cord set.
|WARNINGS |
Any interruption of the protective (grounding)
conductor (inside or outside the instrument) or
disconnecting the protective earth terminal will
cause a potential shock hazard that could result in
personal injury. (Grounding one conductor of a
two conductor outlet is not sufficient protection.)
In addition, verify that a common ground exists
between the unit under test and this instrument
prior to energizing either unit.
Whenever it is likely that the protection has been
impaired, the instrument must be made inoperative
and be secured against any unintended operation.
If this instrument is to be energized via an auto-
transformer (for voltage reduction) make sure the
common terminal is connected to neutral (that is,
the grounded side of the mains supply).
Servicing instructions are for use by service-
trained personnel only. To avoid dangerous elec¬
tric shock, do not perform any servicing unless
qualified to do so.
Adjustments described in the manual are per¬
formed with power supplied to the instrument
while protective covers are removed. Energy avail¬
able at many points may, if contacted, result in
personal injury.
Capacitors inside the instrument may still be
charged even if the instrument has been discon¬
nected from its source of supply.
For continued protection against fire hazard, re¬
place the line fuse(s) only with 250V fuse(s) ofthe
same current rating and type (for example, normal
blow, time delay, etc.). Do not use repaired fuses or
short circuited fuseholders.
SAFETY SYMBOLS
_L- Instruction manual symbol: the product
~ will be marked with this symbol when it is
necessary for the user to refer to the in¬
struction manual (see Table ofContents for
page references).
^
A Indicates hazardous voltages.
Indicates earth (ground) terminal.
The WARNING sign denotes a
hazard. It calls attention to a
procedure, practice, or the like,
which, ifnot correctly performed
or adhered to, could result in per¬
sonal injury. Do not proceed be¬
yond a WARNING sign until the
indicated conditions are fully
understood and met.
WARNING
The CAUTION sign denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like, which, if not correctly
performed or adhered to, could
result in damage to or destruc¬
tion of part or all of the product.
Do not proceed beyond a CAU¬
TION sign until the indicated
conditions are fully understood
and met.
CAUTION \
IX

General Information Model 8672A
MODEL 8672A
EXTENDER BOARDS LINE POWER CABLE
FUSE
^
^
NOTE: See ACCESORIES SUPPLIED in Section I for more details.
Figure 1-1. HP Model 8672A and Accessories Supplied.
1-0

Model 8672A General Information
SECTION I
GENERAL INFORMATION
1-1. INTRODUCTION
1-2. This manual contains information pertinent to
installation, operation, testing, adjusting, and
servicing the Hewlett-Packard Model 8672A
Synthesized Signal Generator. The Model 8672A
will generally be referred to as the Synthesizer
throughout this manual.
1-3. Information pertaining to the Hewlett-Packard
Interface Bus (HP-IB) as it relates to the Synthe¬
sizer is found in various sections of this manual.
Section VIII contains a diagnostic program for
checkout of HP-IB functions. A remote operator's
check is also found in Section VIII.
1-4. Figure 1-1 shows the Synthesizer with all sup¬
plied accessories.
1-5. Packaged with this manual is an Operating
Information Supplement. This is simply a copy of
the first three sections of this manual. This supple¬
ment should stay with the instrument for use by
the operator. Additional copies may be ordered
separately through your nearest Hewlett-Packard
office. The part number is listed on the title page
of this manual.
1-6. On the title page of this manual, below the
manual part number, is a "Microfiche" part num¬
ber. This number may be used to order 100 x
150 mm (4 x 6-inch) microfilm transparencies of
the manual. Each microfiche contains up to 96
photo-duplicates of the manual pages. The micro¬
fiche package also includes the latest Manual
Changes supplement as well as all pertinent Service
Notes.
1-7. SPECIFICATIONS
1-8. Instrument specifications are listed in Table
1-1. These specifications are the performance
standards, or limits against which the instrument
may be tested.
1-9. SAFETY CONSIDERATIONS
1-10. This product is a Safety Class I instrument
(provided with a protective earth terminal). The in¬
strument and manual should be reviewed for safety
markings and instructions before operation.
1-11. The Synthesizer and all related documenta¬
tion must be reviewed for familiarization with
safety markings and instructions before operation.
Refer to the Safety Considerations page found at
the beginning of this manual for a summary of the
safety information.
1-12. Safety information pertinent to the task at
hand (installation, operation, performance testing,
adjustments, or service) is found throughout this
manual.
1-13. INSTRUMENTS COVERED BY MANUAL
1-14. Options. Electrical options 001, 002, 003,
004, 005 and various mechanical options are docu¬
mented in this manual. The differences are noted
under the appropriate paragraph such as Options in
Section I, 'the Replaceable Parts List and the sche¬
matic diagrams.
1-15. Serial Numbers. Attached to this instrument
is a serial number plate. The serial number is in the
form 1234A00123. The first four digits and the
letter comprise the serial 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 num¬
ber prefix(es) as listed under SERIAL NUMBERS
on the title page.
1-16. 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.
1-17. MANUAL CHANGE SUPPLEMENTS
1-18. An instrument manufactured after the print¬
ing of this manual may have a serial prefix that is
not listed on the title page. This unlisted serial pre¬
fix indicates that the instrument is different from
those documented in this manual. The manual for
this instrument is supplied with a yellow Manual
Change supplement that contains "change infor¬
mation" that documents the differences.
1-19. In addition to change information, the sup¬
plement may contain information for correcting
errors in the manual. To keep this manual as cur¬
rent and accurate as possible, Hewlett-Packard
recommends that you periodically request the
latest Manual Changes supplement. The supple¬
ment for this manual is keyed to this 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.
1-1

General Information Model 8672A
Table 1-1. Specifications (1 of 4)
SPECIFICATIONS
FREQUENCY CHARACTERISTICS
Range; 2.0 to 18.0 GHz (overrange to 18.599 997 GHz)
Resolution: 1 kHz, 2.0-6.199 999 GHz
2 kHz, 6.2-12.399 998 GHz
3 kHz, 12.400 002-18.0 GHz
Time Base:
Internal: 10 MHz; Aging Rate is < 5 x lO'^/day
after 30 day warmup1'2 .
External: 5 or 10 MHz; 0.1 to 1 Vrms nominal into
50 ohms3.
Reference Outputs: 10 MHz and 100 MHz, 0.2 Vrms
nominal into 50 ohms.
Frequency Accuracy: same as time base2.
Switching Time (CW and AIV1 modes): < 15 ms to be
within 1 kHz for frequencies from 2—6.2 GHz, with¬
in 2 kHz from 6.2 to 12.4 GHz, and within 3 kHz
from 12.4-18 GHz; < 15 ms to be within 3 dB of
final amplitude level for any frequency change on
the same band.
SPECTRAL PURITY CHARACTERISTICS
Harmonics (up to 18 GHz): <-25dBc.
Sub-harmonics and Multiplies (up to 18 GHz): <-25dBc.
Power Line Related and Spurious: (Due to fan rotation;
within 5 Hz below line frequency and multiples):
Option 003 only (400 Hz operation)
Spurious (CW and AM modes4):
Non-harmonically related: <—70 dBc, 2.0-6.2 GHz
<-64 dBc, 6.2-12.4 GHz
<-60dBc, 12.4-18.0 GHz
Power Line Related and Spurious: (Due to fan rota¬
tion within 5 Hz below line frequency and
multiples):
Except Option 003 Instruments (400 Hz operation)
Carrier (Fc)
Frequency
Range
(GHz)
2.0-6.2
6.2-12.4
12.4-18
Power Line Related and Spurious Levels at
Frequency Offset (fg) from Carrier (Fc)
fg <2 kHz
-40 dBc
-34 dBc
-30 dBc
2kHz<fo<8kHz
-50 dBc
-44 dBc
-40 dBc
fo>8 kHz
-65 dBc
-59 dBc
-55 dBc
Single-Sideband Phase Noise (1 Hz BW, CW mode):
Carrier(Fc)
Frequency
Range
(GHz)
2.0-6.2
6.2-12.4
12.4-18.0
Power Line Related and Spurious Levels At
Frequency Offset (to) From Carrier (Fc)
fo<300 Hz
-50 dBc
-44 dBc
-40 dBc
300Hz<fo<1kHz
-60 dBc
-54 dBc
-50 dBc
fo >1 kHz
-65 dBc
-59 dBc
-55 dBc
Frequency
Range
(GHz)
2.0-6.2
6.2-12.4
12.4-18.0
SSB Phase Noise Ratio (in 1 Hz BW,
CW mode) at Specified Offset Frequency*
10 Hz
-58dB
-52dB
-48dB
100 Hz
-70dB
-64dB
-60dB
1kHz
-78dB
-72dB
-68dB
10kHz
-86dB
-80dB
-76dB
100kHz
-HOdB
-104dB
-lOOdB
*dB referenced to carrier (dBc)
Reference is kept at operating temperature in STAND-BY mode with the instrument connected to Mains power. I'or instruments dis¬
connected from Mains power less than 24 hours, the aging rate is ^.6 x 10" /day after a 24 hour warmup.
0 Overall accuracy of the internal reference oscillator is a function of time base calibration ± aging rate ± temperature effects ± line
voltage effects. Typical temperature and line voltage effects are <1 x 10'10 /°C and <5 x 10"10/+5% —10% line voltage change.
q Stability and spectral purity will be partially determined by characteristics of external reference oscillator.
In AM mode, external FM signals at rates <100 kHz must be disconnected. In CW mode, external AM and FM signals
at rates <^ 100 kHz must be disconnected.
1-2

Model 8672A General Information
Table 1-1. Specifications (2 of 4)
RF OUTPUT CHARACTERISTICS
Level: +3 to -120 dBm, +15°C to +35°C 5- 6-12
Total Indicated Meter Accuracy (+15°C to +35°C):7' 8- 9
Frequency
Range (GHz)
2.0-6.2
6.2-12.4
12.4-18.0
Indicated Meter Accuracy at OUTPUT LEVEL RANGE Switch Setting
0 dBm
(No Attenuation)
±1.75 dB
± 2.0 dB
±2.25 dB
-10 dBm
±2.25 dB
±2.5 dB
±2.85 dB
-20dBm
±2.45 dB
±2.7 dB
±3.05 dB
-30 dBm and Below
± L75 dB ±0.3 dB/10 dB step
below 0 dBm range
±2.0 dB ±0.3 dB/10 dB step
below 0 dBm range
±2.25 dB ±0.4 dB/10 dB step
below 0 dBm range
Remote Programming Accuracy7'
8: 0.75 dB better than meter accuracy indicated above.
Flatness (0 dBm range, +15°C to +35°C)7'9: ±0.75 dB, 2.0-6.2 GHz
±1.00 dB, 2.0-12.4 GHz
±1.25 dB, 2.0-18.0 GHz
Output Level Switching Time: < 20 ms7'10.
Impedance: 50 ohms
Source SWR:11 Typically <2.0
additional power available on +10 dBm range (overrange), but for power settings above the maximum specified level, spurious
oscillations may degrade performance.
fi °
For Option 001, 034 and 038 instruments, RF output level specification changes to +5 to —10 dBm from +15 to +35 C; for Option
00
004, +2.0 dBm max.; Option 005, +4 to —10 dBm from +16 to +35 C? for Option 008, +8 dBm to —120 dBm from +15 C to
+35°C. The RF output level also changes when options are combined. When Option 001, 034 or 038 is combined with Option 008,
the RF output level specification is +10 to —10 dBm. When Options 004 and 008 are combined, the RF output level specification
is +7 dBm to —120 dBm. However, when Options 005 and 008 are combined, the RF output level specification is +9 dBm to —10 dBm.
Applies for internal leveling only.
Specification includes allowances for meter accuracy (typically ±0.50 dB), detector linearity, temperature, flatness, attenuator accuracy
and measurement uncertainty. All but the attenuator accuracy and the measurement error can be calibrated out with a power meter
at fixed vernier settings.
For Option 004 and 005 instruments, total indicated meter accuracy and flatness are degraded by an additional ± 0.25 dB.
Typically "^10 ms for any change on same output level range.
On the 0 dBm and —10 dBm output level range, characteristic applies only at the RF output frequency.
For power settings >• 0 dBm and changes in frequency setting from <^ 10 GHz to > 16 GHz, a setting period may be required for the
output power to stabilize at the set level.
1-3

General Information Model 8672A
Table 1-1. Specifications (3 of 4)
AMPLITUDE MODULATION CHARACTERISTICS
Depth (for meter readings 0 dBm and below, +15°C to
+35°C):12
0-75% from 2.0-6.2 GHz
0-60% from 6.2-12.4 GHz
0-50% from 12.4-18.0 GHz
Rates (3 dB bandwidth):
10 Hz-100 kHz.
Frequency Response (100 Hz-10 kHz rates):
± 0.25 dB.
Sensitivity (percent AM per Vpk):
30%/V and 100%/V ranges. Maximum input 1 Vpk
into 600 ohms nominal.13
Distortion (for rates less than 10 kHz and meter readings
0 dB and below, +15°C to +35°C):
< 3% at 30% depth
<4% at 50% depth
<5% at 75% depth
Indicated Meter Accuracy (100 Hz-10 kHz rates): ±5%
of range.
Accuracy Relative to EXT AM Input Level (100 Hz-
10 kHz rates): ±10% of range.
Incidental 0M (Rates < 10 kHz, 30% Depth):
< 0.7 Rad, 2.0-6.2 GHz
< 1.8 Rad, 6.2-12.4 GHz
< 1.2 Rad, 12.4-18.0 GHz
Incidental FM:
Incidental <fM x f^y^.
FREQUENCY MODULATION CHARACTERISTICS
Peak Deviation (maximum): The smaller of 10 MHz or
f^d x 5, 2.0-6.2GHz; 10 MHz or f^ x 10, 6.2-
12.4 GHz; 10 MHz or f^^ x 15,12.4-18.0 GHz
Rates (3 dB bandwidth typical): 30,100 kHz/V ranges,
50 Hz to 10 MHz; 300 kHz/V and 1, 3,10 MHz/V
ranges, 1 kHz to 10 MHz.
Frequency Response (relative to 100 kHz rate):
±2.0 dB, 100 Hz-3 MHz, 30 and 100 kHz/V ranges.
±2.0 dB, 3 kHz-3 MHz, 300 kHz/V and 1, 3,
10 MHz/V ranges.
Sensitivity (peak deviation per Vpk):
30,100, 300 kHz/V and 1, 3, 10 MHz/V ranges,
maximum input 1 Vpk into 50 ohms nominal.14
Harmonic and Non-Harmonic Distortion:15 <l2% for
rates < 3 kHz, decreasing linearly with frequency to
5% at 20 kHz rate. < 5% for 20 to 100 kHz rates.
Residual FM in FM and CW Modes (noise and power line
related)'6:
Mode/Range
CW, 30,100 kHz/V
300 kHz/V, 1, 3,
10 MHz/V
Residual FM in Post Detection
Bandwidth
300-3 kHz
16 Hz—rms
20 Hz—rms
50Rz-15kRz
80 Hz—rms
100 Hz—rms
Indicated Meter Accuracy (at 100 kHz rate):17
±10% of full scale at +15°C to +35°C.
±15% of full scale at 0 to +55°C.
Accuracy Relative to External Input Level (at 100 kHz
rate):'7 ±7% of range at +15°C to +35°C
±10% of range at 0 to +55°C.
Incidental AM (rates <100 kHz, peak deviation <1 MHz):
< 10%.
12
13
14
15
16
17
The meter reading of output power level when using AM is carrier level only (i.e., does NOT include power in AM sidebands).
1.0V peak gives maximum depth on each range. AM depth is linearly controlled by varying input level between 0 and 1 Vpk.
1 Vpk gives maximum deviation on each range. Peak deviation is linearly controlled by varying input level between 0 and 1 Vpk.
For certain FM modulating frequencies, spurious FM signals (non-harmonic distortion) may occur. After demodulation in an external
FM discriminator, the contribution to distortion of these spurious FM signals is typically less than 0.6%.
Residual FM doubles in 6.2—12.4 GHz range; triples in 12.4—18.0 GHz range.
For FM rates other than 100 kHz, add FM frequency response specification.
1-4

Model8672A General Information
Table 1-1. Specifications (4 of 4)
REMOTE PROGRAMMING CHARACTERISTICS
Frequency: Programmable over full range (up to
18.599 997 GHz) with same resolution as in man¬
ual mode.
Output Level; Programmable in 1 dB steps, +3 to
—120 dBm, plus the 10 dB of overrange.
AM Modulation: OFF, 30%/Vpk, and 100%/Vpk ranges.
FM Modulation: OFF; 30, 100, 300 kHz/Vpk; 1, 3,
10 MHz/Vpk ranges.
Other: RF ON, RF OFF, ALC INT, ALC EXT XTAL,
ALC EXT, PWR MTR.
Programming Format: HP-IB (Hewlett-Packard Interface
Bus).
GENERAL CHARACTERISTICS
Operating Temperature Range: 0° to 55°C.
Leakage: Meets radiated and conducted limits of
MIL-I-6181D.
Power: 100, 120, 220, or 240V, +5%, -10% 48-66 Hz
300 VA maximum.
Net Weight: 27.2 kg (60 Ib).
Dimensions: 600 mmD x 425 mmW x 133 mmH
(23-5/8" x 16-3/4" x 5-1/4").
1-20. DESCRIPTION
1-21. The HP Model 8672A Synthesized Signal
Generator has a frequency range of 2000 to 18 000
MHz. The output is leveled and calibrated from +3
to —120 dBm. AM and/or FM modulation modes
can be selected. The frequency, output level, mod¬
ulation modes, and most other modes or functions
can be remotely controlled using the HP-IB pro¬
gramming format.
1-22. Frequency
1-23. Frequencies from 2000 to 18 000 MHz
(overrange to 18 599.997 MHz) can be tuned from
the front panel. Minimum resolution is 1 kHz from
2000 to 6199.999 MHz, 2 kHz from 6200 to
12 399.998 MHz and 3 kHz from 12 400.002
to 18 000 MHz. Tuning resolutions of 100 MHz,
1 MHz, 10 kHz, or 1 kHz minimum are selected by
front panel pushbuttons.
1-24. Frequency stability is dependent on the
time base, either an internal or external oscillator.
The internal crystal oscillator operates at 10 MHz
while an external oscillator must operate at 5 or
10 MHz. The heart of the Synthesizer, a YIG tuned
oscillator (YTO), is phase-locked to the time base
oscillator.
1-25. Output Level
1-26. The output of the Synthesizer is excep¬
tionally flat due to the action of the internal auto¬
matic leveling control (ALC) loop. The accuracy of
the total indicated output level (the sum of the
front panel meter reading and the attenuator range)
is increased.
1-27. The OUTPUT LEVEL VERNIER controls
the output level as indicated by the front panel
meter ( +3 to -10 dB). The OUTPUT LEVEL
RANGE switch sets the attenuation of the output
level in twelve 10 dB steps (0 to —110 dBm). The
+10 dBm range (overrange) is also controlled by
the OUTPUT LEVEL RANGE switch.
1-28. Modulation Modes
1-29. Both amplitude and frequency modulation
capabilities are available in the instrument using
either front panel switches or remote program¬
ming. External drive signals are used for both AM
and FM operation. AM depth and FM deviation
are linear with the applied external voltage. Full
scale modulation is attained with 1.0 V-peak.
1-30. Two ranges of AM depth are selectable
either from the front panel or via remote pro¬
gramming. The front panel meter can be used
to set the AM depths of up to 75% between
2000 MHz and 6200 MHz, up to 60% between
6200 MHz and 12 400 MHz, and 50% between
12 400 MHz and 18 000 MHz. Amplitude mod¬
ulation can be performed at any frequency be¬
tween 10 Hz and 100 kHz.
1-5

General Information Model 8672A
1-31. FM peak deviation can be set using the front
panel meter. At output frequencies below 6200 MHz,
peak deviation is limited to 10 MHz or five times the
modulation frequency, whichever is lower. From 6200
to 12 400 MHz, peak deviation is limited to the lesser of
10 MHz or ten times the modulation frequency; from
12 400 to 18 000 MHz the lesser of 10 MHz or fifteen
times the modulation frequency. Usable modulation
rates fall between 50 Hz and 10 MHz. Six ranges of
deviation sensitivity are selectable either by the front
panel switches or via remote programming.
1-32. Miscellaneous Outputs and Indicators
1-33. The front panel meter indicates output level,
AM depth, or FM peak deviation. The meter mode is
selected by a front panel switch.
1-34. External leveling is selected by a front panel
switch. A power meter or crystal detector may be used
as the leveling loop detector.
1-35. Phase-locked reference outputsj)f 10 and 100
MHz are available on the rear panel.
1-36. Six front panel status indicators make the Syn¬
thesizer operation easier and aid in reducing possible
operator error.
1-37. Remote Operation
1-38. The Synthesizer is fully programmable via the
Hewlett-Packard Interface Bus. Intheremote mode all
front panel controls are disabled except the LINE and
METER MODE switches.
1-39. The output level is selected in 1 dB steps. The
programmed output level is more accurate than can be
obtained in the local mode. This occurs because the
output level is set by programming rather than being
set by monitoring the meter reading. The meter read¬
ing may be in error due to meter nonlinearity.
1-40. OPTIONS
1-41. Electrical Options
1-42. Options 001 and 005. Both of these options
omit the internal RF step attenuator and have only
two positions on the OUTPUT LEVEL RANGE
switch. Option 001's output level specification is +5 to
-10 dBm. Option 005 has a rear panel RF OUTPUT
connector; its output level specification is +4 to -10
dBm, and its total indicated level accuracy and flat¬
ness specifications are degraded by ±0.25 dB.
1-43. Option 002. The internal 10 MHz crystal refer¬
ence is omitted.
1-44. Option 003. A special fan allows operation
from 400 Hz power Mains.
1-45. Option 004. The Synthesizer's RF output con¬
nector is located on the rear panel. Maximum output
poweris +2.0 dBm. Total indicated level accuracy and
flatness is degraded by ±0.25 dB.
1-46. Options 034 and 038. Both of these options
omit the internal RF step attenuator; have specified
RF output between +5 and -10 dBm; have an addi-
tienaT^connector on the rear panel for controlling an
, 86726A\Frequency
Extension Unit, and can display
f the entire frequencyrange ofan 8672S system (that is,
10^
MHz to 18 GHz). The Option 038 has only two
i positions on the OUTPUT LEVEL RANGE switch.
\jb>4^. Mechanical Options
1-48. The following options may have been ordered
and received with the Synthesizer. If they were not
received with the original shipment and are now
required, they must be ordered from your nearest
Hewlett-Packard office using the part number in¬
cluded in each of the following paragraphs.
1-49. Chassis Slide Mount Kit. This kit is extremely
useful when the Synthesizer is rack mounted. Access
to internal circuits and components;, or the rear panel
is possible withoutremoving the Synthesizer from the
rack. Order HP part number 1494-0017. When this kit
comes with the Synthesizer, it is identified as Option
006. Ifthe instrument rack mounting slides are to be
mounted in a standard EIArack, then an adapter (HP
Part No. 1494-0023) is needed. The slides without the
adapter can be directly mounted in the HP system
enclosures.
1-50. Front Handle Kit. Ease of
handlingis increased
with the front panel handles. Order HP part number
5061-0089.
1-51. Rack Flange Kit. The Synthesizer can be solidly
mounted to the instrument rack using this kit. Order
HP part number 5061-0077.
1-52. Rack Flange and Front Handle Combination
Kit. This kit is not a front handle kit and rack flange
kit packaged together. The combination is made up of
a unique part which includes both functions. Order
HP part number 5061-0083.
1-53. COMPATIBILITY
1-54. The Synthesizer is compatible with HP-IB as
indicated by the following code: AHl, C0, DCl,
DT0, L4, LE0, PP2, RL2, SH1, SRI, T6 and TE0.
An explanation of the compatibility code may be
1-6

Model 8672A General Information
found in the IEEE Standard 488-1975, "IEEE
Standard Digital Interface for Programmable
Instrumentation.''
1-55. For more detailed information relating to
programmable control of the Synthesizer, refer to
Section III in this manual.
1-56. SELECTING THE HP-IB ADDRESS
1-57. The HP-IB address switches are located with¬
in the Synthesizer. The switches represent a two-
digit octal number. This number corresponds to
talk and listen address characters which an HP-IB
controller is capable of generating. A table in Sec¬
tion II shows all HP-IB talk and listen addresses.
Refer to the paragraph entitled HP-IB Address and
Parallel Poll Response Selection in Section II.
1-58. ACCESSORIES SUPPLIED
1-59. The accessories supplied with the Synthesizer
are shown in Figure 1-1.
a. The line power cable may be supplied in
several combinations of plugs. Refer to Power
Cables in Section II.
b. Fuses with a 3.0A rating for 100/120 Vac
(HP 2110-0003) and a 1.5A rating for 220/240
Vac (HP 2110-0043) are supplied. One fuse is fac¬
tory installed according to the voltage available in
the country of destination. Refer to Line Voltage
Selection in Section II.
c. There are four extender boards supplied
which aid in performance testing, adjusting, and
troubleshooting the instrument.
1. One 30-pin (15 x 2) extender board,
HP part number 08672-60117.
2. Two 36-pin (18x2) extender boards,
HP part number 08672-60020.
3. One 3-section, 30-pins (15 x 2) per
section, extender board, HP part num¬
ber 08672-60016 (for use in the A2
Assembly).
1-60. EQUIPMENT REQUIRED BUT NOT
SUPPLIED
1-61. For Option 002 instruments which lack an
internal frequency standard, an external reference
must be used. The performance of the external
reference should at least match the specifications
and, in particular, the frequency accuracy1 and
spectral purity of the HP Model 10544C Crystal
Oscillator. When using an external oscillator,
microphonics or line related spurious signals may
increase.
1-62. An external signal source is required if
amplitude or frequency modulation is desired. For
AM, the source should have a variable output of 0
to 1 Vpk into 600 ohms, modulation rates up to
100 kHz, and distortion of <1%. For FM, the
source should have a variable output of 0 to 1 Vpk
into 50 ohms, modulation rates up to 10 MHz, and
distortion of <1%. The HP 651B and 654A test
oscillators are adequate for modulating the Synthe¬
sizer and meet the stated requirements.
1-63. A remotely programmable audio source
would be convenient for full remote control of
modulation levels and rates.
1-64. EQUIPMENT AVAILABLE
1-65. The Synthesizer has an HP-IB interface and
can be used with any HP-IB compatible computing
controller or computer for automatic systems
applications.
1-66. The 11712A Support Kit is available to aid
the user in maintaining and servicing the Synthe¬
sizer. It consists of cables, adaptors, terminations,
prerecorded programs, extender boards and a test
extender board.
1-67. The prerecorded programs are on tape cas¬
settes and are for use with the HP 9830A and HP
9825A Computing Controllers. The Output Re¬
gister Test Board is intended to aid in trouble¬
shooting the frequency control circuits.
1-68. Refer to the 11712A Support Kit operating
manual for additional information. It may be
ordered through your nearest Hewlett-Packard
office.
1-69. RECOMMENDED TEST EQUIPMENT
1-70. Table 1-2 lists the test equipment and acces¬
sories recommended for use in testing, adjusting,
and servicing the Synthesizer. If any of the recom¬
mended equipment is unavailable, instruments with
equivalent minimum specifications may be used.
Frequency Accuracy: needed 1 ppm; minimum requirement
10 ppm.
1-7

General Information Model 8672A
Table 1-2. Recommended Test Equipment (1 of 3)
Instrument
Adapter
(2 required)
Amplifier, 40 dB
Analyzer,
Audio
Analyzer, Logic
State
Analyzer,
Modulation
Analyzer,
Spectrum
Analyzer,
Spectrum
Attenuator
Cable, Semi-rigid
Cable, HP-IB
Interconnect
Cable, Special
Interconnect
•P = Performance Testing, A = Adjustments, T = Troubleshooting
Critical Specifications
APC-7 to Type-N Male
Frequency Range: 2—18 GHz
Frequency Range, 5 Hz to 10 kHz
Gain: 40 dB (xlOO) into one megohm
Distortion measurement at audio rate
from 1 kHz to 100 kHz, residual
distortion <0.1%
8-bit display
Triggerable
Residual FM at 20 MHz in a 3 kHz
post detection bandwidth <2 Hz
FM demodulation capability at 20 MHz and 100 MHz.
Able to read both peak and average deviation
Frequency response: to 40 kHz
Bandwidth: 1 Hz minimum
Frequency Span Per Division: 5Hz minimum
Amplitude Range: 0 to —70 dB
Frequency Range: 10 kHz—100 MHz
Frequency Span: 0.1—100 MHz
Resolution Bandwidth: 30 Hz-300 kHz
Amplitude Range: +10 to—90 dBm
Vertical Sensitivity: 2 dB per division minimum
Frequency Range: 1 kHz-200 kHz
Frequency Span: 0—50 kHz
Frequency Range: 2—18 GHz
Frequency Span: 50 kHz to 200 MHz per division
Resolution Bandwidth: 30 Hz—300 kHz
Amplitude Range: +10 to—90 dBm
Vertical Sensitivity: 2 dB per division minimun
3dB
10 dB
50n
3.6 mm (0.141") diameter with compatible SMA connector
HP-IB Compatible
Special (see Figure 1-3)
Recommended
Model
HP 11525A
HP 8447A Opt. 001
HP 8903A
HP 1600A
HP 8901A
HP 3580A
HP 8553B/8552B/141T
HP 8556A
HP 8565A
HP 8491A, Opt.003
HP 8491A, Opt.010
Locally fabricated
HP 10833A
Locally fabricated
Use*
p
p
P
T
P
P
A,T
P,A,T
P,A,T
A
P
P
P,A,T
A
1-8