1 INTRODUCTION AND SPECIFICATIONS 1-1 1-1. INTRODUCTION 1-1 1-2. UNPACKING THE SIGNAL GENERATOR 1-1 1-3. SAFETY 1-2 1-4. ACCESSORIES 1-3 1-5. SIGNAL GENERATOR SPECIFICATIONS 1-3 2 INSTALLATION 2-1 2-1. INTRODUCTION 2-1 2-2. INITIAL INSPECTION 2-1 2-3. SERVICE INFORMATION 2-1 2-4. Warranty 2-1 2-5. Service 2-1 2-6. SETTING UP THE 6080A/AN 2-2 2-7. Power Requirements 2-2 2-8. Line Voltage Selection and Fuse Replacement 2-2 2-9. Rack or Bench Mounting the 6080A/AN 2-3 2-10. Frequency Reference 2-3 2-11. Local and Remote Operation 2-3 2-12. Power-On Sequence 2-3 3 SIGNAL GENERATOR FEATURES 3-1 3-1. GENERAL INFORMATION 3-1 3-2. FRONT PANEL FEATURES 3-1 3-3. Display Features 3-1 3-4. Front Panel Keys and Connectors 3-1 3-5. REAR PANEL FEATURES 3-1 4 FRONT PANEL OPERATION 4-1 4-1. INTRODUCTION 4-1 4-2. PARAMETER ENTRY AND MODIFICATION 4-1 4-3. Parameter Entry 4-1 4-4. Bright-Digit Edit 4-2 4-5. Step Increment and Decrement 4-3 4A RF FREQUENCY 4A-1 4A-1. INTRODUCTION 4A-1 4A-2. RF FREQUENCY ENTRY 4A-1 4A-3. RF FREQUENCY STEP ENTRY 4A-1 4A-4. RF FREQUENCY RELATIVE MODE 4A-2 4A-5. EXTERNAL FREQUENCY REFERENCE 4A-3 4A-6. RF FREQUENCY BANDS 4A-3 4B RF AMPLITUDE 4B-1 4B-1. INTRODUCTION 4B-1 4B-2. RF AMPLITUDE ENTRY 4B-1 4B-3. RF AMPLITUDE UNITS CONVERSION 4B-2 4B-4. ALTERNATE DB REFERENCE UNITS SELECTION 4B-2 4B-5. UNTERMINATED OUTPUT (EMF) MODE 4B-3 4B-6. RF AMPLITUDE STEP ENTRY 4B-4 4B-7. RF AMPLITUDE RELATIVE MODE 4B-4 4B-8. RF OUTPUT ON/OFF 4B-6 4B-9. RF AMPLITUDE BANDS 4B-6 4B-10. RF AMPLITUDE FIXED-RANGE MODE 4B-7 4B-11. ALTERNATE OUTPUT COMPENSATION MODES 4B-8 4B-12. SELECTING ALTERNATE OUTPUT COMPENSATION DATA ... 4B-8 4C MODULATION 4C-1 4C-1. INTRODUCTION 4C-1 4C-2. MODULATION, AM 4C-1 4C-3. AM Depth and AM Depth Step Size Entry 4C-2 4C-4. Internal AM 4C-3 4C-5. External AM 4C-3 4C-6. External AM, DC Coupled 4C-3 4C-7. MODULATION, FM/ø 4C-3 4C-8. FM/ø Deviation and FM/ø Step Size Entry 4C-4 4C-9. FM/ø Units Conversion 4C-5 4C-10. Internal FM/ø 4C-6 4C-11. External FM/ø 4C-6 4C-12. External DCFM 4C-6 4C-13. FM Bands 4C-7 4C-14. Low Distortion/Fixed-Range FM 4C-8 4C-15. Low Rate FM 4C-9 4C-16. High Rate ø 4C-9 4C-17. MODULATION, PULSE 4C-10 4C-18. External Pulse 4C-10 4C-19. Internal Pulse 4C-10 4C-20. INTERNAL MODULATION OSCILLATOR 4C-10 4C-21. Modulation Frequency Entry and Step Size Entry 4C-10 4C-22. Extended Resolution Modulation Frequency Entry 4C-12 4C-23. Modulation Level Entry and Step Size Entry 4C-12 4C-24. Modulation Output On/Off 4C-14 4C-25. Internal Modulation Waveform Selection 4C-14 4C-26. Internal Pulse Generator Mode 4C-15 4D MEMORY 4D-1 4D-1. ORGANIZATION OF 6080A/AN MEMORY 4D-1 4D-2. STORE AND RECALL ENTRY 4D-3 4D-3. MEMORY SEQUENCE ENTRY 4D-4 4D-4. MEMORY SEQUENCE DIVIDERS 4D-4 4D-5. MEMORY LOCATION LOCK 4D-6 4D-6. RESET MEMORY TO DEFAULT MEMORY LOCATION 4D-6 4D-7. SINGLE PARAMETER STORE AND RECALL 4D-6 4E SWEEP 4E-1 4E-1. GENERAL DESCRIPTION 4E-1 4E-2. SELECTING THE DIGITAL SWEEP FIELD 4E-2 4E-3. DIGITAL SWEEP MODES 4E-2 4E-4. DIGITAL SWEEP SYMMETRY 4E-3 4E-5. DIGITAL SWEEP DWELL TIME 4E-3 4E-6. DIGITAL FREQUENCY SWEEP 4E-4 4E-7. Frequency Sweep Width Entry 4E-5 4E-8. Frequency Sweep Increment Entry 4E-5 4E-9. Digital Frequency Sweep Example 4E-6 4E-10. DIGITAL AMPLITUDE SWEEP 4E-6 4E-11. Amplitude Sweep Width 4E-8 4E-12. Amplitude Sweep Increment Entry 4E-8 4E-13. Example Digital Amplitude Sweep 4E-9 4E-14. CALIBRATION OF RECORDER/OSCILLOSCOPE 4E-10 4E-15. ANALOG FREQUENCY SWEEP 4E-10 4F SPECIAL FUNCTIONS 4F-1 4F-1. GENERAL DESCRIPTION 4F-1 4F-2. SPECIAL FUNCTION ENTRY 4F-3 4F-3. VIEWING ENABLED SPECIAL FUNCTIONS 4F-3 4F-4. THE SPCL ANNUNCIATOR 4F-3 4F-5. MISCELLANEOUS SPECIAL FUNCTIONS 4F-3 4F-6. Clear Special Functions 4F-3 4F-7. Restore Instrument Preset State 4F-4 4F-8. Execute Self-Test and Display Self-Test Results 4F-4 4F-9. Display Loaded Options 4F-4 4F-10. Display Instrument ID and Software Revision Level 4F-4 4F-11. Blank Front Panel Display 4F-4 4F-12. Select Repeat Rate for Step Keys 4F-4 4F-13. Configure Edit Knob and Step Keys 4F-4 4G ERROR AND STATUS REPORTING .. 4G-1 4G-1. GENERAL DESCRIPTION 4G-1 4G-2. THE STATUS KEY 4G-1 4G-3. SELF-TEST AND CALIBRATION/COMPENSATION DATA STATUS 4G-2 5 REMOTE OPERATION 5-1 5-1. INTRODUCTION 5-1 5-2. SETTING UP THE IEEE-488 INTERFACE .. 5-1 5-3. Address Setup Procedure 5-1 5-4. Talker/Listener Mode Selection Procedure 5-2 5-5. Compatibility Language Selection Procedure 5-2 5A REMOTE PROGRAMMING 5A-1 5A-1. INTRODUCTION 5A-l 5A-2. COMMAND SYNTAX INFORMATION 5A-2 5A-3. Parameter Syntax Rules 5A-2 5A-4. Extra Space Characters 5A-3 5A-5. Terminators 5A-3 5A-6. Incoming Character Processing 5A-3 5A-7. Response Message Syntax 5A-4 5A-8. INPUT BUFFER OPERATION 5A-4 5A-9. COMMANDS 5A-4 5A-10. Multiple Commands 5A-4 5A-11. Command Processing 5A-4 5A-12. Command Restrictions 5A-5 5A-13. Commands That Require the CAL|COMP Switch Set 5A-5 5A-14. REMOTE/LOCAL STATE TRANSITIONS 5A-5 5A-15. CHECKING THE INSTRUMENT STATUS 5A-7 5A-16. Serial Poll Status Byte (STB) 5A-7 5A-17. BIT ASSIGNMENTS FOR THE STB AND SRE 5A-7 5A-18. SERVICE REQUEST LINE (SRQ) 5A-9 5A-19. SERVICE REQUEST ENABLE REGISTER (SRE) 5A-9 5A-20. PROGRAMMING THE STB AND SRE 5A-10 5A-21. Event Status Register (ESR) 5A-10 5A-22. BIT ASSIGNMENTS FOR THE ESR AND ESE 5A-10 5A-23. EVENT STATUS ENABLE REGISTER (ESE) 5A-12 5A-24. PROGRAMMING THE ESR AND ESE .. 5A-12 5A-25. Output Queue 5A-13 5A-26. Error Queue 5A-13 5A-27. Instrument Status Register 5A-14 5A-28. BIT ASSIGNMENTS FOR THE ISR, ISCR, AND ISCE ..... 5A-14 5A-29. INSTRUMENT STATUS CHANGE REGISTER (ISCR) 5A-14 5A-30. INSTRUMENT STATUS CHANGE ENABLE REGISTER (ISCE) 5A-15 5A-31. PROGRAMMING THE ISR, ISCR, AND ISCE 5A-15 5A-32. Status Queue 5A-16 5A-33. IEEE-488 INTERFACE CONFIGURATION 5A-16 5A-34. BUS COMMUNICATION OVERVIEW 5A-16 5A-35. Definition: Queries and Commands 5A-17 5A-36. Functional Elements of Commands 5A-17 5A-37. Interface Messages 5A-19 5A-38. THE IEEE-488 CONNECTOR 5A-21 5A-39. REMOTE PROGRAM EXAMPLES 5A-22 5A-40. Using the *OPC?, *OPC, and *WAI Commands 5A-22 5A-41. Using the *DDT and TRG Commands 5A-23 5B REMOTE COMMAND TABLE 5B-1 5B-1. REMOTE COMMAND SUMMARY 5B-1 5B-2. REMOTE COMMANDS 5B-1 5C TALK-ONLY/LISTEN-ONLY OPERATION 5C-1 5C-1. INTRODUCTION 5C-1 5C-2. TALK-ONLY OPERATION 5C-1 5C-3. LISTEN-ONLY OPERATION 5C-2 5C-4. LISTEN-ONLY/TALK-ONLY EXAMPLE 5C-2 5D COMPATIBILITY LANGUAGES 5D-1 5D-1. INTRODUCTION 5D-1 5D-2. PROGRAMMING THE LANGUAGE 5D-1 5D-3. Incompatibilities 5D-1 5D-4. Converting 6060 and 6070 Programs to Use the 6080 Language 5D-2 APPENDICES A INSTRUMENT PRESET STATE A-l B SPECIAL FUNCTION TABLE B-l C REJECTED ENTRY ERROR CODES C-l D OVERRANGE/UNCAL STATUS CODES D-l E SELF-TEST STATUS CODES E-l F REAR PANEL AUX CONNECTOR PINOUT F-l

1 INTRODUCTION AND SPECIFICATIONS 1-1 1-1. INTRODUCTION 1-1 1-2. UNPACKING THE SIGNAL GENERATOR 1-1 1-3. SAFETY 1-2 1-4. ACCESSORIES 1-3 1-5. SIGNAL GENERATOR SPECIFICATIONS 1-3 2 THEORY OF OPERATION 2-1 2-1. INTRODUCTION 2-1 2-2. GENERAL DESCRIPTION 2-1 2-3. Front Panel Section 2-2 2-4. Upper/Lower Module Sections 2-2 2-5. Rear Panel Section 2-2 2-6. FUNCTIONAL DESCRIPTION 2-2 2-7. Frequency 2-2 2-8. Frequency Modulation 2-4 2-9. Phase Modulation 2-4 2-10. Output/Level Control 2-5 2-11. Amplitude Modulation 2-5 2-12. Pulse Modulation 2-5 2-13. Internal Modulation Oscillator 2-6 2-14. Power Supply Description 2-6 2-15. DIGITAL CONTROLLER SOFTWARE DESCRIPTION 2-6 2-16. User Interface 2-6 2-17. Calibration/Compensation Memory 2-7 2-18. Self-Test 2-7 2-19. Status Signals 2-7 3 CLOSED-CASE CALIBRATION 3-1 3-1. INTRODUCTION 3-1 3-2. Front Panel Calibration 3-2 3-3. Remote Calibration 3-2 3-4. Calibration Data 3-3 3-5. AM CALIBRATION 3-4 3-6. Front Panel AM Calibration Procedure 3-4 3-7. Remote AM Calibration Procedure 3-6 3-8. FM CALIBRATION 3-7 3-9. Front Panel FM Calibration Procedure 3-8 3-10. Remote FM Calibration 3-9 3-11. RF LEVEL CALIBRATION 3-10 3-12. Front Panel Level Calibration Procedure 3-11 3-13. Remote Level Calibration Procedure 3-13 3-14. REFERENCE OSCILLATOR CALIBRATION 3-14 3-15. Front Panel Reference Oscillator Calibration Procedure 3-15 3-16. Remote Reference Oscillator Calibration Procedure 3-16 4 PERFORMANCE TESTS 4-1 4-1. INTRODUCTION 4-1 4-2. TEST EQUIPMENT 4-1 4-3. POWER-ON TEST 4-4 4-4. FREQUENCY ACCURACY TEST 4-5 4-5. SYNTHESIS TEST 4-5 4-6. HIGH-LEVEL ACCURACY TEST 4-6 4-7. MID-LEVEL ACCURACY TEST 4-8 4-8. LOW-LEVEL ACCURACY TEST 4-9 4-9. ALTERNATE-LEVEL ACCURACY TEST 4-10 4-10. FLATNESS TEST 4-13 4-11. OUTPUT LEAKAGE TEST 4-14 4-12. HARMONIC AND LINE-RELATED SPURIOUS TEST 4-15 4-13. PHASE NOISE AND NON-HARMONIC SPURIOUS TESTS 4-16 4-14. MODULATION TESTS 4-17 4-15. VOLTAGE STANDING-WAVE RATIO (VSWR) TESTS 4-23 4-16. PULSE TESTS 4-24 5 ACCESS PROCEDURES 5-1 5-1. INTRODUCTION AND SAFETY 5-1 5-2. LOCATION OF MAJOR ASSEMBLIES 5-3 5-3. ACCESS INSTRUCTIONS 5-3 5-4. Removing the Front Panel Section 5-3 5-5. Removing the Rear Panel Section 5-3 5-6. Removing the A2 Coarse Loop PCA 5-4 5-7. Removing the A3 Sub-Synthesizer VCO PCA 5-4 5-8. Removing the A4 Sub-Synthesizer PCA 5-5 5-9. Removing the A5 Coarse Loop VCO PCA 5-5 5-10. Removing the A6 Mod Oscillator PCA 5-5 5-11. Removing the A8 Output PCA 5-5 5-12. Removing the A9 Sum Loop VCO PCA 5-6 5-13. Removing the A10 Premodulator PCA 5-6 5-14. Removing the A11 Modulation Control PCA 5-6 5-15. Removing the A12 Sum Loop PCA 5-7 5-16. Removing the A13 Controller PCA 5-7 5-17. Removing the A14 FM PCA 5-8 5-18. Removing the A20 Attenuator/RPP Assembly 5-8 5-19. Removing the A22 Delay Cable Assembly 5-8 6 CIRCUIT DESCRIPTIONS, TROUBLESHOOTING, AND ALIGNMENT 6-1 6-1. INTRODUCTION 6-1 6-2. MODULE REPLACEMENT 6-4 6-3. A1 Display PCA 6-5 6-4. A2 Coarse Loop PCA 6-5 6-5. A3 Sub-Synthesizer PCA 6-5 6-6. A4 Sub-Synthesizer PCA 6-5 6-7. A5 Coarse Loop VCO PCA 6-5 6-8. A6 Mod Oscillator PCA 6-5 6-9. A7 Relay Driver PCA 6-5 6-10. A8Output PCA 6-5 6-11. A9 Sum Loop VCO PCA 6-5 6-12. A10 Premodulator PCA 6-6 6-13. A11 Modulation Control PCA 6-6 6-14. A12 Sum Loop PCA 6-6 6-15. A13 Controller PCA 6-6 6-16. A14 FM Board PCA 6-6 6-17. A15 Power Supply PCA 6-6 6-18. A19 Switch PCA 6-6 6-19. A20 Attenuator/RPP Assembly (A7, A21, A30) 6-6 6-20. A22 Delay Line Assembly (A25+A26+Delay Cable+Trim Cable) ....... 6-6 6-21. UPDATING COMPENSATION MEMORY WITH MODULE EXCHANGE DATA 6-7 6-22. PARTS REPLACEMENT 6-8 6-23. SELF-TEST DESCRIPTION 6-8 6-24. Digital Tests 6-8 6-25. AM Tests 6-9 6-26. FM Tests 6-9 6-27. øM Tests 6-9 6-28. DCFM Test 6-10 6-29. Coarse Loop Tests 6-11 6-30. Sub-Synthesizer Tests 6-11 6-31. Sum Loop Tests 6-11 6-32. RF Output Tests 6-12 6-33. Pulse Modulator Tests 6-12 6-34. Filter Tests 6-12 6-35. STATUS SIGNALS AND STATUS CODES 6-13 6-36. SOFTWARE DIAGNOSTIC FUNCTIONS 6-14 6-37. Digital Control Latch Test 6-14 6-38. Instrument Diagnostic State 6-14 6-39. Set Internal DACs 6-14 6-40. Display Synthesizer Loop Frequencies 6-15 6A POWER SUPPLY 6A-1 6A-1. POWER SUPPLY BLOCK DIAGRAM 6A-1 6A-2. POWER SUPPLY CIRCUIT DESCRIPTION 6A-1 6A-3. POWER SUPPLY TROUBLESHOOTING 6A-4 6A-4. Troubleshooting Procedure 6A-4 6A-5. POWER SUPPLY ADJUSTMENT PROCEDURE 6A-5 6B DIGITAL CONTROLLER 6B-1 6B-1. DIGITAL CONTROLLER BLOCK DIAGRAM 6B-1 6B-2. DIGITAL CONTROLLER CIRCUIT DESCRIPTION (A13) 6B-1 6B-3. Microprocessor 6B-1 6B-4. Memory 6B-1 6B-5. Memory Control 6B-3 6B-6. Front Panel Interface 6B-3 6B-7. IEEE-488 Interface 6B-3 6B-8. Attenuator Control Interface 6B-3 6B-9. Module I/O 6B-3 6B-10. Status and Control 6B-4 6B-11. DIGITAL CONTROLLER TROUBLESHOOTING 6B-4 6B-12. RF Control 6B-4 6B-13. Microprocessor Kernel 6B-5 6B-14. Clock 6B-5 6B-15. Power-On Reset 6B-5 6B-16. Unused Microprocessor Inputs 6B-5 6B-17. Bus Error 6B-5 6B-18. Interrupts 6B-5 6B-19. Microprocessor Bus 6B-6 6B-20. Address Decoder 6B-6 6B-21. I/O Diagnostic Tests 6B-7 6B-22. CALIBRATION/COMPENSATION MEMORY 6B-8 6B-23. Calibration/Compensation Memory Status 6B-8 6B-24. Repairing Calibration/Compensation Memory Checksum Errors .. 6B-9 6B-25. Calibration/Compensation Memory Origin Status 6B-9 6B-26. FRONT PANEL CIRCUIT DESCRIPTION 6B-9 6B-27. Display PCA 6B-10 6B-28. Data Communications 6B-10 6B-29. Display Filament Voltage 6B-10 6B-30. Bright-Digit Effect 6B-10 6B-31. Switchboard Interface 6B-10 6B-32. Remote Footswitch 6B-10 6B-33. Edit Knob Interface 6B-11 6B-34. Display Blanking 6B-11 6B-35. Operate/Standby Selection 6B-11 6B-36. FRONT PANEL TROUBLESHOOTING 6B-11 6B-37. Display and Controls 6B-11 6C FREQUENCY SYNTHESIS 6C-1 6C-1. FREQUENCY FAULT TREE 6C-1 6C-2. SUB-SYNTHESIZER BLOCK DIAGRAM 6C-1 6C-3. SUB-SYNTHESIZER CIRCUIT DESCRIPTION (A4) 6C-1 6C-4. SUB-SYNTHESIZER TROUBLESHOOTING 6C-9 6C-5. SUB-SYNTHESIZER ADJUSTMENTS 6C-13 6C-6. Steering DAC Full Scale Adjustment 6C-13 6C-7. Lower Clamp Adjustment, R99 6C-13 6C-8. Upper Clamp Adjustment, R98 6C-14 6C-9. SSB Mixer LO Drive Adjustment, R106 6C-14 6C-10. 10-kHz Notch Adjustment, L56 6C-15 6C-11. SUB-SYNTHESIZER VCO (A3) CIRCUIT DESCRIPTION 6C-16 6C-12. SUB-SYNTHESIZER VCO TROUBLESHOOTING 6C-16 6C-13. COARSE LOOP CIRCUIT DESCRIPTION (A2) 6C-17 6C-14. REFERENCE SECTION BLOCK DIAGRAM 6C-17 6C-15. COARSE LOOP BLOCK DIAGRAM 6C-20 6C-16. COARSE LOOP TROUBLESHOOTING 6C-22 6C-17. COARSE LOOP PCA ADJUSTMENTS 6C-26 6C-18. Discriminator Video Amplifier Offset Adjustment, R102 6C-26 6C-19. Steering Gain Adjustment, R221 6C-28 6C-20. Acquisition Oscillator Level Adjustment, R227 6C-28 6C-21. 40-MHz Oscillator Adjustment, L601 6C-28 6C-22. 80-MHz Filter Tuning, L612 and L613 6C-29 6C-23. 80-MHz Level Adjustment, R617 6C-30 6C-24. 2-MHz Notch Adjustment, L205 6C-30 6C-25. Alternate Reference Frequency Selection 6C-31 6C-26. COARSE LOOP VCO (A5) CIRCUIT DESCRIPTION 6C-31 6C-27. COARSE LOOP VCO TROUBLESHOOTING 6C-32 6C-28. SUM LOOP BLOCK DIAGRAM 6C-32 6C-29. SUM LOOP (A12) CIRCUIT DESCRIPTION 6C-34 6C-30. RF Section 6C-34 6C-31. Audio Section 6C-35 6C-32. SUM LOOP TROUBLESHOOTING 6C-38 6C-33. SUM LOOP ASSEMBLY ADJUSTMENTS 6C-41 6C-34. Steering Level Adjustment, R112 6C-41 6C-35. Buffer Gain Match Adjustment, R121 6C-42 6C-36. FM Null Adjustment, R116 6C-42 6C-37. Loop Gain Adjustment, R167 6C-43 6C-38. Acquisition Oscillator Level Adjustment, R132 6C-44 6C-39. SUM LOOP VCO (A9) CIRCUIT DESCRIPTION 6C-44 6C-40. SUM LOOP VCO TROUBLESHOOTING 6C-45 6D RF LEVEL/AM 6D-1 6D-1. RF LEVEL FAULT TREE 6D-1 6D-2. RF LEVEL BLOCK DIAGRAM 6D-1 6D-3. RF LEVEL CIRCUIT DESCRIPTION 6D-3 6D-4. RF Path 6D-3 6D-5. Leveling Loop 6D-5 6D-6. Level Control 6D-6 6D-7. RF LEVEL TROUBLESHOOTING 6D-6 6D-8. Unleveled Condition 6D-8 6D-9. Output Assembly Test Point Signal Information 6D-9 6D-10. RF LEVEL ADJUSTMENTS 6D-10 6D-11. Mod Control PCA Level DAC Offset Adjustment, R23 6D-10 6D-12. Mod Control PCA AM DAC Offset Adjustment, R8 6D-11 6D-13. Mod Control PCA Detector Offset Adjustment, R28 6D-12 6D-14. Mod Control PCA AM Depth Adjustment, R10 6D-13 6D-15. Mod Control PCA RF Level Adjustment, R20 6D-14 6D-16. Mod Control PCA External Modulation Level Indicator Adjustment, R71 6D-15 6D-17. Mod Control PCA Sum Steer Gain Adjustment 6D-15 6D-18. Output PCA Het Mixer Level Adjustment, R72 6D-16 6D-19. Output PCA Het Level Adjustment, R10 6D-17 6D-20. Premodulator PCA Bandwidth Adjustment, R51 and C7 6D-17 6D-21. Output PCA Q16 Bias Adjustment, R96 6D-18 6D-22. Output PCA Q9 Bias Adjustment, R1 6D-19 6D-23. Output PCA) Gain Flatness Adjustment, C201 6D-19 6D-24. FM Gain Adjustment, R82, on Mod Control PCA 6D-20 6D-25. FM Steer Gain, R101 on Mod Control PCA 6D-20 6D-26. FM INV Balance, R102 on Mod Control PCA 6D-20 6D-27. ATTENUATOR/REVERSE POWER PROTECTION (RPP) 6D-20 6D-28. ATTENUATOR RPP TROUBLESHOOTING 6D-21 6E FREQUENCY AND PHASE MODULATION 6E-1 6E-1. FM/øM FAULT TREE 6E-1 6E-2. FM/øM BLOCK DIAGRAM 6E-2 6E-3. CIRCUIT DESCRIPTION 6E-2 6E-4. Oscillator Section 6E-2 6E-5. Divider Section 6E-4 6E-6. Phase Detectors, Loop Circuits, and Logic Section 6E-4 6E-7. Modulation Section 6E-7 6E-8. MODULATION CONTROL CIRCUIT DESCRIPTION 6E-10 6E-9. FM Input Voltage Processing 6E-10 6E-10. FM Steer Voltage Generation 6E-10 6E-11. FM Control Signals Generation 6E-10 6E-12. FM TROUBLE SHOOTING (A14) 6E-11 6E-13. Frequency Check 6E-11 6E-14. Modulation Check 6E-12 6E-15. Input Signals and Control Input Signals Checks 6E-12 6E-16. FM ADJUSTMENTS 6E-13 6E-17. Adjustments on the Modulation Control PCA (A11) 6E-13 6E-18. Alignment of FM PCA (A14) 6E-14 6F INTERNAL MODULATION OSCILLATOR 6F-1 6F-1. MODULATION OSCILLATOR BLOCK DIAGRAM 6F-1 6F-2. INTERNAL MODULATION OSCILLATOR CIRCUIT DESCRIPTION 6F-1 6F-3. Direct Digital Synthesized Wave Generator 6F-1 6F-4. Pulse Generator 6F-3 6F-5. Signal Routing 6F-3 6F-6. MOD OSCILLATOR TROUBLESHOOTING AND ADJUSTMENTS 6F-4 6F-7. Direct Digital Synthesizer Troubleshooting 6F-4 6F-8. Pulse Generator Troubleshooting 6F-5 7 LIST OF REPLACEABLE PARTS 7-1 TABLE OF CONTENTS 7-1 7-1. INTRODUCTION 7-2 7-2. HOW TO OBTAIN PARTS 7-2 7-3. SERVICE CENTERS 7-3 8 SCHEMATIC DIAGRAMS 8-1 TABLE OF CONTENTS 8-1 APPENDICES A. INSTRUMENT PRESET STATE A-l B. SPECIAL FUNCTION TABLE B-l C. REJECTED ENTRY ERROR CODES C-l D. OVERRANGE/UNCAL STATUS CODES D-l E. SELF-TEST STATUS CODES E-l F. COMPENSATION MEMORY STATUS CODES F-l G. EXAMPLE CALIBRATION CONTROLLER PROGRAMS G-l H. COMPENSATION PROCEDURES H-l I. REAR PANEL AUX CONNECTOR PINOUT 1-1