FOLD-IN ILLUSTRATIONSTitleFigure 1-1. Modem, Low Speed Wire Line MD-474(P)/G.Chapter 1 INTRODUCTION - TM-11-5805-424-150010Section II. DESCRIPTION AND DATAAudiofrequency (cps)Description - TM-11-5805-424-150013Figure 1-2. Modem, Low Speed Wire Line MD-674(P)/G, Modem Subassembly MX-73(*)/G, and Clock Module Group OA-8072/GFigure 1-3. Running spares.Figure 1-5. Modem, Low Speed Wire Line MD-674(P)/G, removed from case, top view, less Modem Subassembly MX-73(*)/G Clock Module Group OA-8072/G Figure 1-6. Modem, Low Speed Wire Line MD-74(P)/G removed from caseFigure 1-7. Modem , Low Speed Wire Line MD-674(P)/G removed from case, bottom view.Figure 1-8. Modem, Low Speed Wire Line MD-674(P)/G, rear view, less access cover.Figure 1-9. Single-channel, secure, terminal facilities, block diagramFigure 1-10. Multiplex terminal facilities, block diagramFigure 1-11. Signal-channel repeater facility, block diagramCHAPTER 2 INSTALLATIONFigure 2-1. Typical packaging diagramStrapping OptionsFigure 2-3. Control shelf, controls and test jacksConnectionsFigure 2-5. Printed-circuit card assembly strap terminal locationsRemoteSection III. INITIAL ADJUSTMENTSLoop-Back AdjustmentsSystem AdjustmentsFigure 2-7. Plug-in module of Modem Subassembly MX-7373/G, MX-7375/G, MX-7383/G, or MX-7385/G.Figure 2-8. Plug-in module of Modem Subassembly MX-7379/G.Equipment AlterationCHAPTER 3 OPERATION AND OPERATOR'S MAINTENANCEOperation Under Unusual Conditions - TM-11-5805-424-150037CHAPTER 4 ORGANIZATIONAL MAINTENANCE - TM-11-5805-424-150038Organizational Preventive Maintenance Checks and Services ChartSection II. TROUBLESHOOTING AND REPAIRTroubleshooting Chart. cont'dReplacement of PartsReplacement of Parts cont'dChapter 4 FUNCTIONING OF EQUIPMENTTiming CircuitsOrder-Wire CircuitsBistable Multivibrator StagesFigure 5-1. Common input bistable stages, schematic diagram and logic symbol.Figure 5-2. Two-input bistable stages schematic diagram and logicFigure 5-4. Two-input bistable stage, +6-volt clamped output, schematic diagram and logic symbolFigure 5-5. AND gate stages, schematic diagram and logic symbol.Figure 5-6. OR gate stages, schematic diagram and logic symbol.Figure 5-7. Amplifier stages, schematic diagram and logic symbol.Transmit Output and Carrier Alarm CircuitsReceive Input and Carrier Alarm CircuitsTalk-Request Detector Timing CircuitsInitial TimerDemodulator CircuitsDual Output Polar Driver CircuitsDelay Equalization CircuitsSend TimingExternal ClockFigure 5-8. Phase-lock loop, timing waveforms.Receive TimingClock CorrectionFigure 5-9. Receive timing add-subtract control logic waveforms.Receive Data cont'dOrder-wire Circuit OperationAlarm CircuitsLoss-of-Transmit-Carrier AlarmLoss-of-Receive-Carrier AlarmCommon Alarm CircuitryChapter 6 DIRECT SUPPORT AND GENERAL SUPPORT AND DEPOT MAINTENANCEOperational TestsPreliminary ProceduresFigure 6-1. Operational tests, connection diagram.Figure 6-2. Printed-circuit cord assembly A1 (PC 80034090), component location diagramFigure 6-3. Printed-circuit card assembly A2 (PC 80034100),component location diagramFigure 6-4. Printed-circuit card assembly A3 (PC 80034140), component location diagramFigure 6-5. Printed-circuit card assembly A4 (PC 80034080), component location diagram.Figure 6-6. Printed-circuit card assembly A5 (PC 80034150), component location diagram.Figure 6-7. Printed-circuit card assembly A6 (PC 80034120), component location diagram.Figure 6-8. Printed-circuit card assembly A7 (PC 80034130), component location diagram.Figure 6-9. Printed-circuit card assembly A8 (PC 80034020), component location diagram. Figure 6-10. Printed-circuit card assembly A9 (PC 80034050), component location diagram.Figure 6-11. Printed-circuit card assembly A10 (PC 80034040), component location diagram.Figure 6-12. Printed-circuit card assembly A11 (PC 80034030), component location diagram.Figure 6-13. Printed-circuit card assembly A12 (PC 80034060), component location diagram.Figure 6-14. Printed-circuit card assembly A13 (PC 80034010), adapter card diagram.Figure 6-15. Printed-circuit card assembly A14 (PC 80034170), component location diagram.Figure 6-16. Printed-circuit cord assembly A15 (PC 80034160), component location diagram.Figure 6-18. Power supply submodule, component location diagram.Figure 6-19. Printed-circuit card assembly A18A1A1 through AS1A1 (PC 80034210), component location diagramFigure 6-22. Printed-it card assembly A18A2, A19A2 (PC 80034200), component location diagram.Figure 6-23. Printed-circuit card assembly A20A2, A21A2, A22A2 (PC 80034190), component location diagram.Figure 6-24. Printed-circuit card assembly A23A2 through A29A2 (PC 80034180), component location diagram.Figure 6-25. Printed-circuit card assembly A25A3 (PC 80034230), component location diagram.Figure 6-26. Printed-circuit card assembly A33A2 (PC 80034110), component location diagram.Figure 6-27. Modem, Low Speed Wire Line MD-674(P)/G, removed from case, top view.Figure 6-28. Modem, Low Speed Wire Line MD-674(P)/G, removed from case, bottom view.Figure 6-29. Modem, Low speed Wire Line 74 (P)/G, removed from, case, front panel, rear view.Figure 6-30. Plug-in module of Modem Subassembly MX-73(*)/G, bottom view.Figure 6-31. PC card assembly A1 (PC 80034090) voltage and resistance diagram.Figure 6-32. PC card assembly A3 (PC 80034140) voltage and resistance diagram.Figure 6-33. PC card assembly A5 (PC 80034150) voltage and resistance diagram.Figure 6-34. PC card assembly A6 (PC 80034130) voltage and resistance diagram.Figure 6-35. PC card assembly, A8 (PC 80034120) voyage and resistance diagram.Figure 6-36. PC card assembly A9 (PC 80034050 ) voltage and resistance diagram.Figure 6-37. PC card assembIy A10 (PC 80034040) voltage and resistance diagram.Figure 6-38. PC card assembIy A11 (PC 80034030) voltage and resistance diagram.Figure 6-39. PC card assembIy A14 (PC 80034170) voltage and resistance diagram.Figure 6-40. PC card assembIy A15 (PC 80034160) voltage and resistance diagram.Figure 6-41. PC card assembIy A25A3 (PC 80034230) voltage and resistance diagram.Localizing TroublesTroubleshooting Chart-Continued - TM-11-5805-424-150115Troubleshooting Chart-Continued - TM-11-5805-424-150116Troubleshooting Chart-Continued - TM-11-5805-424-150117Troubleshooting Chart-Continued - TM-11-5805-424-150118Troubleshooting Chart-Continued - TM-11-5805-424-150119Troubleshooting Chart-Continued - TM-11-5805-424-150120Troubleshooting Chart-Continued - TM-11-5805-424-150121Troubleshooting Chart-Continued - TM-11-5805-424-150122Troubleshooting Chart-Continued - TM-11-5805-424-150123Troubleshooting Chart-Continued - TM-11-5805-424-150124Isolating Troubles in Logic GatesIsolating Troubles in Amplifier StagesRepair ProceduresRepair Procedures cont'dChapter 7 GENERAL SUPPORT TESTING PROCEDURESPhysical Tests and InspectionData TestProcedure- Continued - TM-11-5805-424-150132Procedure- Continued - TM-11-5805-424-150133Procedure- Continued - TM-11-5805-424-150134Timing Tests - TM-11-5805-424-150135Timing Tests cont'd Alarm Tests Alarm Tests cont'd - TM-11-5805-424-150138 Alarm Tests cont'd - TM-11-5805-424-150139 Alarm Tests cont'd - TM-11-5805-424-150140Summary of Performance StandardsTiming Tests - TM-11-5805-424-150142Alarm TestsCHAPTER 8 ADJUSTMENTS AND FINAL TESTINGAdjustment of Variable Control Oscillator (VCO)Alarm AdjustmentsReceiver Carrier Alarm AdjustmentsOrder-Wire Circuit AdjustmentsFigure 8-1. Modem, Low Speed Wire Line MD-674(*)/G, removed from case, top view, Less Modem Subassembly MX-73(*)/G and Clock Module Group OA-8072/G, adjustment at locationsFigure 8-2. Frequency determining module (FDM) waveform check.Figure 8-18. 6 volt power supply regulator circuits assembly A14 (PC 80034170), schematic diagram.CHAPTER 8.1 Input Capacitance Tests Input Impedance TestsInput Resistance TestAPPENDIX A REFERENCES - TM-11-5805-424-150156APPENDIX B MAINTENANCE ALLOCATIONTool and Test Equipment Requirements - TM-11-5805-424-150158SECTION II MAINTENANCE ALLOCATION CHART FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/GSECTION II MAINTENANCE ALLOCATION CHART FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/G cont'd - TM-11-5805-424-150160SECTION II MAINTENANCE ALLOCATION CHART FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/G cont'd - TM-11-5805-424-150161SECTION II MAINTENANCE ALLOCATION CHART FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/G cont'd - TM-11-5805-424-150162SECTION II MAINTENANCE ALLOCATION CHART FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/G cont'd - TM-11-5805-424-150163SECTION II MAINTENANCE ALLOCATION CHART FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/G cont'd - TM-11-5805-424-150164SECTION II MAINTENANCE ALLOCATION CHART FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/G cont'd - TM-11-5805-424-150165SECTION III TOOL AND TEST EQUIPMENT REQUIREMENTS FOR MODEM, LOW SPEED WIRE LINE MD-674(P)/GSECTION IV. REMARKS - TM-11-5805-424-150167APPENDIX C COMPONENTS OF END ITEM LIST - TM-11-5805-424-150168SECTION II. COMPONENTS OF END ITEM - TM-11-5805-424-150169SECTION II. COMPONENTS OF END ITEM SECTION II. COMPONENTS OF END ITEM - TM-11-5805-424-150171SECTION II. COMPONENTS OF END ITEM - TM-11-5805-424-150172SECTION II. COMPONENTS OF END ITEM - TM-11-5805-424-150173Figure 5-3. Two-input bistable stages, -6-volt clamped output, schematic diagram and logic symbol.Figure 6-17. printed-circuit card assembly A 16 (PC 80034070), harness card diagram.Figure 6-42, Main chassis voltage and resistance diagram.Figure 6-43. Plug-in module of Modem .;Subassembly MX-7372/ G. MX. 7374 / G, MX- 7376/ GFigure 6-44. Plug-in module of Modem .;Subassembly MX-7373/ G. MX. 7375 / G, MX- 7377/ GFigure 6-45. Plug-in module Subassembly MX-78379/G, wiring diagramFigure 6-46. Power supply submodule (assembly A1A17) wiring diagramFigure 7-. Test setup, alarm test.Figure 7-1. Test setup, data tests.Figure 7-2. Test setup, timing tests.Figure 8-3. Color code markings for MIL-STD resistors, capacitors, and inductors.Figure 8-4. Modem, low speed wire line MD-674 (P)/G, block diagram.Figure 8-5. Modem, Low Speed Wire Line MD-674(P)/G, logic diagram.Figure 8-6. Variable-control oscillator circuits assembly A1 (PC 80034090) schematic diagram.Figure 8-7. 128 divider-A circuits assembly A2 (PC80034100), schematic diagram.Figure 8-8. Add-subtract logic and talk request generator circuits assembly A3 (PC 80034140), schematic diagram.Figure 8-9. 128 divider-B circuits assembly A4 (PC80034080), schematic diagram.Figure 8-10. Dual output polar driver circuits assembly A5 (PC 80034150), schematic diagram.Figure 8-11. Transmit output aid carrier alarm circuits assembly A 6 (PC 80034120), schematic diagram.Figure 8-12. 64 divider circuits assembly A7 (PC 80034130. schematic diagram.Figure 8-13. Demodulator circuits assembly A8 (PC 80034020), schematic diagram.Figure 8-14. Receive input and carrier alarm circuits assembly A9 (PC 80034050), schematic diagram.Figure 8-15. Talk-request detector circuits assembly A10 (PC 80034040), schematic diagram.Figure 8-16. Receive data output circuits assembly A11 (PC 80034030), schematic diagram.Figure 8-17. Input interface and common alarm circuits assembly A12 (PC80034060), schematic diagram.Figure 8-19. 15-volt power supply regulator circuits assembly A15 (PC 80034160), schematic diagram.Figure 8-20. Ac power and rectifier circuit, modem chassis, and power supply submodule, schematic diagram.Figure 8-21. Crystal oscillator and regulator circuit assemblies A1A18A1-A32A1A1 and A18A1A2-A32A1A2 (PC 80034210, PC80034220), schematic diagram.Figure 8-22. One-stage frequency divider circuit assemblies A23A2-A292 (PC 80034180), schematic diagram.Figure 8-23. Two-stage frequency divider circuit assemblies A20A2, A21A2, and A22A2 (PC 80034190) schematic diagram.Figure 8-24. Three-stage frequency divider circuit assemblies A18A2 and A19A2 (PC 80034200), schematic diagram.Figure 8-25. Delay equalizer circuits for MX-7379/G (PC 80034230), schematic diagram.Figure 8-26. Delay equalization circuits (except MX-7379/G) schematic diagrams.Figure 8-27. Clock divider circuits assembly A33A2 (PC 80034110) schematic diagram.Figure 8-28(1). Modem chassis overall wiring diagram (part 1 of 3).Figure 8-28(2). Modem chassis overall wiring diagram (part 2 of 3).Figure 8-28(3). Modem chassis overall wiring diagram (part 3 of 3).TM-11-5805-424-15 Modem Low Speed Wire Line MD-674(P)/G Manual