Maxon Telecom service manual SW5, SM-2000 Control Head

Page 69

SPKR

LED4

LED3

LED2

LED1

SW4

SW3

LED5

CON801

SW5

SW2

C283

D804

D801

D805

R801

C807

C809

SM-2000 CONTROL HEAD

SM-2000 CONTROL HEAD

650-050-0003650-050-0003

Page-65- December 98

Image 69

Contents SM-2000 Page Maxon SM-2000 Mobile Table of ContentsSchematics and Block Diagrams PCB LayoutsSM-2000 Exploded View Specifications Transceiver Nominal PerformanceGeneral Operational Bandwidth BandTransmitter Specfications TX Tone Modulation Characteristics SUB Audible Tones DCSReceiver 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 BoardRF Section SM-2450/UHF UHF TransmitterFrequency Synthesizer Circuit Voltage Controlled Oscillator Circuit First MixerSecond 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 Component Replacement Surface Mount ComponentsSurface 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