Figure 1-1. Digital Voltmeter AN/GSM-64C
CHAPTER 1. INTRODUCTION - TM-11-6625-444-14-20019
Section II. DESCRIPTION AND DATA - TM-11-6625-444-14-20020
Table 1-2. Ac Voltage Ranges*
Table 1-3. Ac Voltage Accuracy
Figrue 1-2. Outline Drawing, Portable Configuration
Figure 1-3. Outline Drawing, Rack Mount Configuration
CHAPTER 2. INSTALLATION - TM-11-6625-444-14-20025
Figure 2-1. AN/GSM-64C Packing Diagram
Figure 2-2. Voltage Selection and Fused Receptacle (Rear Panel)
Figure 2-3. Equipment Connections
Figure 2-4 Rack Mount Installation
CHAPTER 3. OPERATING INSTRUCTIONS - TM-11-6625-444-14-20031
Figure 3-1. Front Panel Controls and Instruments
Table 3-1. Front Panel Controls and Instruments
Table 3-1. Front Panel Controls and Instruments-continued - TM-11-6625-444-14-20034
Table 3-1. Front Panel Controls and Instruments-continued - TM-11-6625-444-14-20035
Figure 3-2. Rear Panel Controls and Instruments
Table 3-2. Rear Panel Controls and Instruments
Figure 3-3. Common Mode Signal Configuration
Figure 3-4. Guarded Signal Configuration
Section II. OPERATlON UNDER NORMAL CONDITIONS
DC/DC Ratio Measurement
Ac Voltage Measurement
Ac+Dc Voltage Measurement
Figure 3-6. Effect of DC Bias on the True Rms Voltage of a Square Wave
Remote Programming
Standby Operation
Section III. PREPARATION FOR MOVEMENT - TM-11-6625-444-14-20047
CHAPTER 4. OPERATOR AND ORGANIZATIONAL MAINTENANCE - TM-11-6625-444-14-20049
Checks and Services
Table 4-3. Organizational Preventive Maintenance Checks and Services
Table 4-3. Organizational Preventive Maintenance Checks and Services-continued
Section IV. TROUBLESHOOTING - TM-11-6625-444-14-20053
Functional Testing - TM-11-6625-444-14-20054
CHAPTER 5. FUNCTIONING OF EQUIPMENT - TM-11-6625-444-14-20055
Table 5-1. Ac Attenuation
Analog to Digital (A/D) Converter
Table 5-3. Ratio Ranging
Section II. LOGIC CIRCUIT DESCRIPTION
Figure 5-1. Range Selection Diagram
Table 5-5. Range Selection Logic, A2-LJ67
Up Range Detector, Minus Voltage
Table 5-7. Autorange Logic, A2-U52
Ratio Autoranging (A1 Assembly)
Ratio Down Range Detector, Minus Input Signal
Figure 5-2. Function Selection Diagram
Timing Waveforms
Figrue 5-3. Timing Waveforms
CHAPTER 6. DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
Figure 6-1. Location of Test Points
Figure 6-2. Location of Adjustments
Section II. TOOLS AND TEST EQUIPMENT - TM-11-6625-444-14-20072
Power Supply Checks
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 1 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 2 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 3 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 4 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 5 of 5)
Figure 6-5. Troubleshooting Flow Chart, Ac Voltage (Sheet 1 of 2)
Figure 6-5. Troubleshooting Flow Chart, Ac Voltage (Sheet 2 of 2)
Figure 6-6. Troubleshooting Flow Chart, Dc/Dc Ratio (Sheet 1 of 2)
Figure 6-6. Troubleshooting Flow Chart, Dc/Dc Ratio (Sheet 2 of 2)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 1 of 4)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 2 of 4)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 3 of 4)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 4 of 4)
Figure 6-8. PCB, Digital Circuit Board
Figure 6-9. PCB, Analog Circuit Board
Section IV. MAINTENANCE OF THE VOLTMETER
Figure 6-10. Digital Voltmeter AN/GSM-64C, Exploded View
Figure 6-11. Rms Converter (A7) Singnal Input Connections
Repair and Replacement - TM-11-6625-444-14-20092
Figure 6-12. Digital Voltmeter AN/GSM-64C, Front Panel Assembly
Assembly - TM-11-6625-444-14-20094
Figure 6-13. Digital Voltmeter AN/GSM-64C, Bottom Cover Explosion
Figure 6-14. Digital Voltmeter AN/GSM-64C, Rear Panel Assembly
Section V. PERFORMANCE ASSURANCE TESTS
Table 6-3. Voltmeter Dc Voltage Accuracy Checks
Table 6-4. Voltmeter Dc Volts Autoranging Checks
Table 6-5. Voltmeter Dc/dc Ratio Autoranging Checks
Figure 6-17. Ac Voltage Accuracy Checks
Section VI. FINAL ADJUSTMENTS
Table 6-7. Minimum Specifications of Equipment Required-continued
Dc Volts Accuracy Adjustments
Figure 6-19. Location of Adjustments, Analog and Ratio Boards
Zero Width Adjustment (A1-R107)
Dc Ratio Accuracy Adjustments
Figure 6-20. DC Ratio Calibration, Equipment Connections
100 V Full Range (A9-R10)/100 Vdc Common Mode (A9-R22)
Figure 6-21. DC Ratio Calibration, Equipment Connections
Figure 6-22. Location of Test Points
Figure 6-23. DC Ratio Auto Range Detector Calibration
Dc Volts Autoranging Adjustments
Figure 6-25. DC Voltage Autoranging, Equipment Connections
Dc/dc Ratio Autoranging Adjustments
Ratio > +180000 Up Range Trip Point
Figure 6-26. DC/DC Ratio Autoranging, Equipment Connections
Figure 6-27. Location of Adjustments, True Rms Board
Figure 6-28. RMS Converter Adjustment, Equipment Connections
Overall Zero Adjustments (A7-R83, R94, R113, R144, R148)
Overall Zero Adjustments (A7-R94, R113, R144, R148)
Dc Turnover Adjustment (A7-R91) - TM-11-6625-444-14-20122
Dc Turnover Adjustment (A7-R91) - TM-11-6625-444-14-20123
Figure 6-29. Crest Factor Adjustment, Equipment Connections
Rms Converter Dc Range Adjustments (A7-R40)
Figure 6-30. DC Volts Accuracy, Equipment Connections
Final Procedure
Figure 6-31. AC Volts Accuracy Check, Equipment Connections
APPENDIX A. REFERENCES - TM-11-6625-444-14-20129
APPENDIX B. MAINTENANCE ALLOCATION - TM-11-6625-444-14-20131
Column Entries - TM-11-6625-444-14-20132
Section II. MAINTENANCE ALLOCATION CHART FOR VOLTMETER AN/GSM-64C
REMARKS - TM-11-6625-444-14-20134
Section III. TOOL AND TEST EQUIPMENT REQUIREMENTS FOR DIGITAL VOLTMETER, AN/GSM-64C
Figure FO-1. Voltmeter Block Diagram
Figure FO-2. Power Supply (A1,A2) Schematic Diagram
Figure FO-3. Dc Volts Attenuator/Analog Switching (A1) Schematic Diagram
Figure FO-4. A/D Converter and Active Filter (A1) Schematic Diagram
Figure FO-5. Auto Range Up/Down Detectors (A1) Schematic Diagram
Figure FO-6. Relay Switching Circuits (A1) Schematic Diagram
Figure FO-7. Function Select Logic (A2) Schematic Diagram
Figure FO-8. Manual Auto Remote Range Circuits (A2) Schematic Diagram
Figure FO-9. Counter and Display Circuits (A2,A3) Schematic Diagram
Figure FO-10. Parallel BCD Output (A2) Schematic Diagram
Figure FO-11. Range Encoder/DP Encoder Circuits (A2) Schematic Diagram
Figure FO-12. Rms Converter Preamplifier and Scaling (A7) Schematic Diagram
Figure FO-13. True Rms Converter (A7) Schematic Diagram
Figure FO-14. Dc Ratio Amplifier (A9) Schematic Diagram
TM-11-6625-444-14-2 Voltmeter Digital AN/GSM-64C (NSN 6625-01-124-0834) (EIC: KNK) Manual
CHAPTER 1. INTRODUCTION - TM-11-6625-444-14-20019
Section II. DESCRIPTION AND DATA - TM-11-6625-444-14-20020
Table 1-2. Ac Voltage Ranges*
Table 1-3. Ac Voltage Accuracy
Figrue 1-2. Outline Drawing, Portable Configuration
Figure 1-3. Outline Drawing, Rack Mount Configuration
CHAPTER 2. INSTALLATION - TM-11-6625-444-14-20025
Figure 2-1. AN/GSM-64C Packing Diagram
Figure 2-2. Voltage Selection and Fused Receptacle (Rear Panel)
Figure 2-3. Equipment Connections
Figure 2-4 Rack Mount Installation
CHAPTER 3. OPERATING INSTRUCTIONS - TM-11-6625-444-14-20031
Figure 3-1. Front Panel Controls and Instruments
Table 3-1. Front Panel Controls and Instruments
Table 3-1. Front Panel Controls and Instruments-continued - TM-11-6625-444-14-20034
Table 3-1. Front Panel Controls and Instruments-continued - TM-11-6625-444-14-20035
Figure 3-2. Rear Panel Controls and Instruments
Table 3-2. Rear Panel Controls and Instruments
Figure 3-3. Common Mode Signal Configuration
Figure 3-4. Guarded Signal Configuration
Section II. OPERATlON UNDER NORMAL CONDITIONS
DC/DC Ratio Measurement
Ac Voltage Measurement
Ac+Dc Voltage Measurement
Figure 3-6. Effect of DC Bias on the True Rms Voltage of a Square Wave
Remote Programming
Standby Operation
Section III. PREPARATION FOR MOVEMENT - TM-11-6625-444-14-20047
CHAPTER 4. OPERATOR AND ORGANIZATIONAL MAINTENANCE - TM-11-6625-444-14-20049
Checks and Services
Table 4-3. Organizational Preventive Maintenance Checks and Services
Table 4-3. Organizational Preventive Maintenance Checks and Services-continued
Section IV. TROUBLESHOOTING - TM-11-6625-444-14-20053
Functional Testing - TM-11-6625-444-14-20054
CHAPTER 5. FUNCTIONING OF EQUIPMENT - TM-11-6625-444-14-20055
Table 5-1. Ac Attenuation
Analog to Digital (A/D) Converter
Table 5-3. Ratio Ranging
Section II. LOGIC CIRCUIT DESCRIPTION
Figure 5-1. Range Selection Diagram
Table 5-5. Range Selection Logic, A2-LJ67
Up Range Detector, Minus Voltage
Table 5-7. Autorange Logic, A2-U52
Ratio Autoranging (A1 Assembly)
Ratio Down Range Detector, Minus Input Signal
Figure 5-2. Function Selection Diagram
Timing Waveforms
Figrue 5-3. Timing Waveforms
CHAPTER 6. DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
Figure 6-1. Location of Test Points
Figure 6-2. Location of Adjustments
Section II. TOOLS AND TEST EQUIPMENT - TM-11-6625-444-14-20072
Power Supply Checks
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 1 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 2 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 3 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 4 of 5)
Figure 6-4. Troubleshooting Flow Chart, Dc Voltage (Sheet 5 of 5)
Figure 6-5. Troubleshooting Flow Chart, Ac Voltage (Sheet 1 of 2)
Figure 6-5. Troubleshooting Flow Chart, Ac Voltage (Sheet 2 of 2)
Figure 6-6. Troubleshooting Flow Chart, Dc/Dc Ratio (Sheet 1 of 2)
Figure 6-6. Troubleshooting Flow Chart, Dc/Dc Ratio (Sheet 2 of 2)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 1 of 4)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 2 of 4)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 3 of 4)
Figure 6-7. Troubleshooting Flow Chart, Auto Ranging (Sheet 4 of 4)
Figure 6-8. PCB, Digital Circuit Board
Figure 6-9. PCB, Analog Circuit Board
Section IV. MAINTENANCE OF THE VOLTMETER
Figure 6-10. Digital Voltmeter AN/GSM-64C, Exploded View
Figure 6-11. Rms Converter (A7) Singnal Input Connections
Repair and Replacement - TM-11-6625-444-14-20092
Figure 6-12. Digital Voltmeter AN/GSM-64C, Front Panel Assembly
Assembly - TM-11-6625-444-14-20094
Figure 6-13. Digital Voltmeter AN/GSM-64C, Bottom Cover Explosion
Figure 6-14. Digital Voltmeter AN/GSM-64C, Rear Panel Assembly
Section V. PERFORMANCE ASSURANCE TESTS
Table 6-3. Voltmeter Dc Voltage Accuracy Checks
Table 6-4. Voltmeter Dc Volts Autoranging Checks
Table 6-5. Voltmeter Dc/dc Ratio Autoranging Checks
Figure 6-17. Ac Voltage Accuracy Checks
Section VI. FINAL ADJUSTMENTS
Table 6-7. Minimum Specifications of Equipment Required-continued
Dc Volts Accuracy Adjustments
Figure 6-19. Location of Adjustments, Analog and Ratio Boards
Zero Width Adjustment (A1-R107)
Dc Ratio Accuracy Adjustments
Figure 6-20. DC Ratio Calibration, Equipment Connections
100 V Full Range (A9-R10)/100 Vdc Common Mode (A9-R22)
Figure 6-21. DC Ratio Calibration, Equipment Connections
Figure 6-22. Location of Test Points
Figure 6-23. DC Ratio Auto Range Detector Calibration
Dc Volts Autoranging Adjustments
Figure 6-25. DC Voltage Autoranging, Equipment Connections
Dc/dc Ratio Autoranging Adjustments
Ratio > +180000 Up Range Trip Point
Figure 6-26. DC/DC Ratio Autoranging, Equipment Connections
Figure 6-27. Location of Adjustments, True Rms Board
Figure 6-28. RMS Converter Adjustment, Equipment Connections
Overall Zero Adjustments (A7-R83, R94, R113, R144, R148)
Overall Zero Adjustments (A7-R94, R113, R144, R148)
Dc Turnover Adjustment (A7-R91) - TM-11-6625-444-14-20122
Dc Turnover Adjustment (A7-R91) - TM-11-6625-444-14-20123
Figure 6-29. Crest Factor Adjustment, Equipment Connections
Rms Converter Dc Range Adjustments (A7-R40)
Figure 6-30. DC Volts Accuracy, Equipment Connections
Final Procedure
Figure 6-31. AC Volts Accuracy Check, Equipment Connections
APPENDIX A. REFERENCES - TM-11-6625-444-14-20129
APPENDIX B. MAINTENANCE ALLOCATION - TM-11-6625-444-14-20131
Column Entries - TM-11-6625-444-14-20132
Section II. MAINTENANCE ALLOCATION CHART FOR VOLTMETER AN/GSM-64C
REMARKS - TM-11-6625-444-14-20134
Section III. TOOL AND TEST EQUIPMENT REQUIREMENTS FOR DIGITAL VOLTMETER, AN/GSM-64C
Figure FO-1. Voltmeter Block Diagram
Figure FO-2. Power Supply (A1,A2) Schematic Diagram
Figure FO-3. Dc Volts Attenuator/Analog Switching (A1) Schematic Diagram
Figure FO-4. A/D Converter and Active Filter (A1) Schematic Diagram
Figure FO-5. Auto Range Up/Down Detectors (A1) Schematic Diagram
Figure FO-6. Relay Switching Circuits (A1) Schematic Diagram
Figure FO-7. Function Select Logic (A2) Schematic Diagram
Figure FO-8. Manual Auto Remote Range Circuits (A2) Schematic Diagram
Figure FO-9. Counter and Display Circuits (A2,A3) Schematic Diagram
Figure FO-10. Parallel BCD Output (A2) Schematic Diagram
Figure FO-11. Range Encoder/DP Encoder Circuits (A2) Schematic Diagram
Figure FO-12. Rms Converter Preamplifier and Scaling (A7) Schematic Diagram
Figure FO-13. True Rms Converter (A7) Schematic Diagram
Figure FO-14. Dc Ratio Amplifier (A9) Schematic Diagram
TM-11-6625-444-14-2 Voltmeter Digital AN/GSM-64C (NSN 6625-01-124-0834) (EIC: KNK) Manual
