Maxon Telecom SM-2000 service manual

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SM-2000

SERVICE MANUAL

MAXON AMERICA, Inc.

10828 N. W. Air World Drive

Kansas City, MO 64153

Phone 816-891-6320 Fax 816-891-8815

680-100-0045 Revision C ECO 98017

December 98

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Contents SM-2000 Page Maxon SM-2000 Mobile Table of ContentsPCB Layouts Schematics and Block DiagramsSM-2000 Exploded View Transceiver Nominal Performance SpecificationsGeneral Band Operational BandwidthTransmitter Specfications SUB Audible Tones DCS TX Tone Modulation CharacteristicsReceiver Accessories RX Tone Demodulation CharacteristicsSubaudible tones CTCSS/DCS Reliability AnalysisIntroduction Check the carton carefully for the following items Unpacking InformationGeneral Description Description of Controls Description of ControlsSM-2000 Rear Panel Digital Circuitry Theory of OperationCTCSS/DCS Decode Circuits CTCSS/DCS Encoder CircuitEeprom PLL RF Section SM-2150/VHF TX VCO RX VCOPrescaler Out of Lock DetectorReceiver RF AmplifierLow Pass Filter Receiver Audio CircuitAudio Amplifier Noise Detect Circuit SQ BoardUHF Transmitter RF Section SM-2450/UHFFrequency Synthesizer Circuit First Mixer Voltage Controlled Oscillator CircuitSecond Oscillator- Mixer- Limiter and FM Detector Squelch Noise Band Pass Filter Squelch Mute CircuitNoise Detector Speaker Audio AmplifierTransmit Tests Test SetupPLL Alignment SM-2150/VHF Alignment ProcedureReceiver Alignment RF Discriminator TuningAutomatic Power Adjustment Squelch AdjustmentModulation Deviation Adjustment CTCSS/DCS 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 Components Component ReplacementSurface Mount Removal Surface Mounted Integrated Circuit Replacement Surface Mount Component ReplacementREF # Description Parts List Common to SM-2000Digital Parts Common on Both VHF & UHF Digital Section REF # Description FRONT-END PCB Assembly Main Board Parts Band ChartPage-38 December Page-39 December Page-40 December Page-41 December SM-2450A UHF Band SM-2450C UHF Band SM-2450D UHF Band SM-2450E UHF Band Band ChartPage-44 December Page-45 December Page-46 December Page-47 December Component Pinout Page-49 December Page-50 December IC409 Voltage Charts SM-2150/VHFPage-52 December Transistor Voltage Chart Voltage Charts SM-2450/UHF IC404 Page-56 December Status Indications & Audible Tones Trouble Shooting Chart SM-2000Page-58 December MMBV109 Replacement Module SchematicsMA-4472 Microphone Schematic Page-61- December Page-62- December Page-63- December Page-64- December SM-2000 Control Head SW5Page-66 December SM-2150/VHF Main Board AssyFront SM-2450/UHF Main Board AssySM-2000 SM-2150/VHF Exploded View Parts List Intentionally Left Blank