编号45：摩托罗拉MOTOROLA-GP300维修手册6880901Z93-B

Table Of ContentsMOTOROLAForewordScope of Manual................................viiHow to Use This Manual..,..,.,,.,,.,,,,,..,,..,,,,viiOther Documentation,,,,,,,,,,,,,,.,,,,,,,,,,,,...,..viiTechnical Support.…viiService Policy.·viiOrdering Replacement Parts...........................viiModel charts..........................................Performance Specifications,,,,,,,,,,,,,,,,,,,,,,,,.,..,.....,..,,,,.t,,,,,,xiiService Aids.t,,,,,,,,,··..xii用Test Equipment....xiiiTest Set Service Cable................Radio Model Information...................Radio Service Software Information .............................Configuring the RIB and Radio......................................................xVSection 1Radio Disassembly/AssemblyOverview..*…….1-1Disassemble Radio...................1-1Remove Battery.…1-1Remove Chassis..,,.,,t,.,,..,,,t··,··÷·1-1Remove Main Board................................1-1Reassemble Radio.…1-2Section 2Theory of OperationOverview,…2.1Microcomputer....:···2-1Microcomputer Power-Up and Reset Routine.................................................2-1Receiver,,。,,,。。。。。。。。,。。。。,。。,。。,。。,。。,。,,,,,,,,,,。,,。,,,,,。,,2-1Intermediate Frequency ([F)................................................................2-2Transmitter.......…2-2Frequency Generation Circuitry.................................................................2-3Synthesizer…….23VCO........................................................................................2-4TX Audio Path.........2-4Internal MIC Bias Switch and External PTT Sense Circuits...................................2-4MIC Amplifier.........................................................................2-4TX Audio Mute Gate....………2-4Pre-emphasis Amp(standard models)..2-4Option'Interface Connector P1(Keypad/Display models)...................................2-5Limiter (Audio Filter IC).........2-5Post-Limiter Filter (Audio Filter IC)......................................................2-5PL Enc0der…2-5DTMF Encoder.......2-5Deviation Attenuators (Audio Filter IC).2-5Motorola,.All Rights ReservedPrinted In U.S.A.19946880901Z93.-B