Midland Radio SP-300 service manual Board Layout Exploded View

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MAXON

SP-300 HAND HELD

Board Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Exploded View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Page -ii-

May 2001

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Contents Service Manual Table of Contents Board Layout Exploded View Current Consumption SpecificationsTemperature Range GeneralFrequency Bands DimensionsWeight Adjacent Channel PowerPeak Deviation @ 1 kHz Nom. Dev +20dB ReceiverRX Tone Demodulation Characteristics SP-300INTRODUCTION FeaturesBusy Channel Lockout VCO Lock Time Description Description of ControlsDigital Circuits Theory of OperationRF Circuits RF Circuits PLL Synthesizer Speaker Audio Amplifier Squelch mute CircuitKHz Band Pass Filter Noise DetectorTo replace the belt clip Maintenance and RepairRemoving & Replacing the Belt Clip Removing the belt clipTo remove the PTT assembly Removing & Replacing the BatteryTo remove the battery To replace the batteryRemoving & Replacing the Antenna & Control Knobs Removing & Replacing the ACCES- Sory ConnectorRemoving & Replacing the Back Cover To remove the Back CoverTo replace the Back Cover To remove the Main Board Removing & Replacing the Main BoardTo replace the Main Board Component Replacement Removing & Replacing the DAUGH- TER BoardsRemoving & Replacing the Speaker Surface Mounted Integrated Circuit Replacement Surface Mount Component ReplacementAlignment Procedure ProgrammingCloning RX VCO S.G. @ 1kHz Audio Test Equipment SetupTP1 Alignment Points DiagramSymptoms Causes Counter Measures Troubleshooting GuideMain Circuit Voltage ChartsReceive State Transmit State REF# Description PART# SP-300 Series UHF & VHF Digital Section Parts List-30- May REF # Description Replacement Modules SP-300 Series VHF RF Section Parts List-32- May -33- May SP-300 Series UHF RF Section Parts List -35- May -36- May -37- May KTA1504SY Component Pinout-39- May Base Diagram PIN Description UHF FRONT-END VHF Power AMPUHF Power AMP VHF FRONT-ENDUHF V.C.O VHF V.C.OACC-200 Battery TcxoFuse SP-300 Series VHF RF Schematic UHF RF Schematic -47- May Board Layout Top Main Board Assembly 416121B -49- May