Maxon Telecom SM-2000 service manual Intentionally Left Blank

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Contents SM-2000 Page Table of Contents Maxon SM-2000 MobileSM-2000 Exploded View Schematics and Block DiagramsPCB Layouts General SpecificationsTransceiver Nominal Performance Transmitter Operational BandwidthBand Specfications Receiver TX Tone Modulation CharacteristicsSUB Audible Tones DCS Subaudible tones CTCSS/DCS RX Tone Demodulation CharacteristicsAccessories Reliability AnalysisIntroduction Unpacking Information Check the carton carefully for the following itemsGeneral Description Description of Controls Description of ControlsSM-2000 Rear Panel CTCSS/DCS Decode Circuits Theory of OperationDigital Circuitry CTCSS/DCS Encoder CircuitEeprom PLL RF Section SM-2150/VHF RX VCO TX VCOReceiver Out of Lock DetectorPrescaler RF AmplifierAudio Amplifier Receiver Audio CircuitLow Pass Filter Noise Detect Circuit SQ BoardFrequency Synthesizer Circuit RF Section SM-2450/UHFUHF Transmitter Second Oscillator- Mixer- Limiter and FM Detector Voltage Controlled Oscillator CircuitFirst Mixer Noise Detector Squelch Mute CircuitSquelch Noise Band Pass Filter Speaker Audio AmplifierTest Setup Transmit TestsSM-2150/VHF Alignment Procedure PLL AlignmentDiscriminator Tuning Receiver Alignment RFSquelch Adjustment Automatic Power AdjustmentCTCSS/DCS Deviation Adjustment Modulation Deviation AdjustmentAlignment Points Diagram SM-2150/VHF SM-2450/UHF Alignment Procedure Page-28 December ∙ Note Release the PTT button when changing channels Page-30 December Alignment Points Diagram SM-2450/UHF Surface Mount Removal Component ReplacementSurface Mount Components Surface Mount Component Replacement Surface Mounted Integrated Circuit ReplacementParts List Common to SM-2000 REF # DescriptionDigital Parts Common on Both VHF & UHF Digital Section Band Chart REF # Description FRONT-END PCB Assembly Main Board PartsPage-38 December Page-39 December Page-40 December Page-41 December SM-2450A UHF Band SM-2450C UHF Band SM-2450D UHF Band Band Chart SM-2450E UHF BandPage-44 December Page-45 December Page-46 December Page-47 December Component Pinout Page-49 December Page-50 December Voltage Charts SM-2150/VHF IC409Page-52 December Transistor Voltage Chart Voltage Charts SM-2450/UHF IC404 Page-56 December Trouble Shooting Chart SM-2000 Status Indications & Audible TonesPage-58 December Replacement Module Schematics MMBV109MA-4472 Microphone Schematic Page-61- December Page-62- December Page-63- December Page-64- December SW5 SM-2000 Control HeadSM-2150/VHF Main Board Assy Page-66 DecemberSM-2450/UHF Main Board Assy FrontSM-2000 SM-2150/VHF Exploded View Parts List Intentionally Left Blank