Figure 1-1. Modem, Digital Data MD-921/G (PSK modem).Chapter 1 INTRODUCTION - TM-11-5820-803-120009Figure 1-2. PSK modem system interface.System ApplicationFigure 1-4. PSK modem viewed from bottom front (bottom cover removed).Figure 1-5. PSK modem applications.Tabulated DataTabulated Data cont'd - TM-11-5820-803-120015CHAPTER 2 SERVICE UPON RECEIPT AND INSTALLATION - TM-11-5820-803-120016Figure 2-1. PSK modem interface.Figure 2-3. Random data modulation spectrum.Coding/Decoding OptionsFigure 2-4. PSK modem theoretical bit error rate performance for various coding configurations (best case performance).Figure 2-5. (Eb/No) = C/KT - 10 log RD.Figure 2-6. Differential encoding and decoding waveshapes.Coding/Decoding ImplementationFigure 2-7. Coder/decoder signal paths.Figure 2-8. External coder/decoder interface phasing.Figure 2-9. Digital user interface.Figure 2-10. Required standard data and clock input charateristics (normal polarity).ICF InterfacesCable classificationFigure 2-14. Attenuation characteristics of RG-217/U cable.Figure 2-15. (Eb/No) as a function of signal/noise meter reading.Figure 2-16. Bit error rate versus signal/noise meter reading for differentially encoded signals using various error coding modesFigure 2-17. Two PSK modems used in ground relay applications.Section II. SITE AND SHELTER REQUIREMENTSSection IV. INSTALLATION INSTRUCTIONSFigure 2-20. PSK modem, rear view.Table 2-3. Site Interface (J5) Signal ListTable 2-4. Coder Interface (J6) Signal ListFigure 2-22. Standard clock input inverter switch S1 (viewed from top of input interface card, SM-D-742037, A2AA2A4).Figure 2-25. LOS/cable driver output level selection S1Figure 2-27. LOS/cable receiver and decoder adjustments.Table 2-5. Direct Digital Output Interface Polarity Selection.Table 2-8. Operation of LOS/Cable Receiver and Decoder Selection Switches.CHAPTER 3 OPERATING INSTRUCTIONS - TM-11-5820-803-120044Table 3-1. Operator Controls, Indicators, and ConnectorsTable 3-1. Operator Controls, Indicators, and Connectors-Continued - TM-11-5820-803-120046Table 3-1. Operator Controls, Indicators, and Connectors-Continued - TM-11-5820-803-120047Table 3-2. Operational Switch Settings.Table 3-3. Self-Test Initial Switch Settings.Receive Link Test ProcedureStopping Procedure for Standby ConditionChapter 4 OPERATOR/CREW MAINTENANCE INSTRUCTIONS - TM-11-5820-803-120052Table 4-1. Preventive Maintenance Checks and Services (Continued)Table 4-4. BER Test Control Settings.Cleaning - TM-11-5820-803-120055Chapter 5 ORGANIZATIONAL MAINTENANCE INSTRUCTIONS - TM-11-5820-803-120056Section III. ORGANIZATIONAL MAINTENANCE TROUBLESHOOTING AND REPAIRTable 5-3. Power Supply-measurements.Figure 5-2. Thumbwheel switch, assembly Terminal boards.Figure 5-3. Power supply removal and installation.Power Supply Removal and Reinstallation ProceduresAPPENDIX A REFERENCES - TM-11-5820-803-120062APPENDIX C MAINTENANCE ALLOCATIONTool and Test Equipment Requirements - TM-11-5820-803-120064SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/GSECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120066SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120067SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120068SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120069SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120070SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120071SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120072SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120073SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120074SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120075SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120076SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120077SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120078SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120079SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120080SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120081SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120082SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120083SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120084SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120085SECTION II. MAINTENANCE ALLOCATION CHART FOR MODEM, DIGITAL DATA-PHASE SHIFT KEYING MD-921/G cont'd - TM-11-5820-803-120086TM-11-5820-803-12 Modem Digital Data MD-921/G (NSN 5820-00-155-8581) Manual