Inside Views, Logic Unit, RF Unit, Cpu, Pll Ic

SECTION 2 INSIDE VIEWS

•LOGIC UNIT

BOTTOM VIEW

AF volume (IC202: M5222FP)

Crystal filter

(X1: CR-639 5.039MH)

CPU

(IC1: M38267M8LGP)

AF mute switch (Q361: 2SJ364)

AF power amplifier

(IC201: TA7368F) IF IC

(IC701: TA31136FN)

•RF UNIT

TOP VIEW

Power amplifier (Q922: 2SK3075)

Drive amplifier (Q921: MRF9745)

APC sensor drive amplifier (Q911:Q913: UN9215XP6401)

WFM RF amplifier circuit

1st mixer

(IC601: ∝PC2757T)

PLL IC

(IC801: ∝PD3140G)

VCO circuit

BOTTOM VIEW

APC control circuit

2 - 2

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Image 6

Motorola IC-T81A, IC-T81E service manual Inside Views, Logic Unit, RF Unit, Cpu, Pll Ic

Contents

Multiband FM Transceiver Repair Notes IntroductionOrdering Parts Sample Order Table of Contents Transmitter SpecificationsGeneral Version 50 MHz 145 MHz 440 MHz 1200 MHz MHz RX only WFM ReceiverBand WFM RF Unit Inside ViewsLogic Unit CPU Removing the Logic Unit Removing the RF Unit Disassembly InstructionsRemoving the Chassis Panel Removing the Shield Plate Logic unit Receiver Circuits Antenna Switching Circuits RF UnitCircuit Description Duplexer Circuit RF Unit 7 1ST Mixer Circuit RF Unit Transmitter Circuits MHz PA DRIVE/POWER Amplifier Circuits RF UnitAPC Circuits RF Unit APC Control Circuit Line Description Power Supply Circuits Voltage LinePLL Circuits VCC 2 I/O Expander IC RF Unit IC3 Port Allocations1 I/O Expander IC RF Unit IC2 Pin Port Description Number Name CPU Logic Unit IC1 ‘ Required Test Equipment Adjustment ProceduresPreparation Connection PLL Adjustment VLV RF Unit Bottom ViewULV RF Unit TOP View 6MLV Sensitivity Receiver AdjustmentDial VHF Logic Unit TOP View Top Push and hold MHz band MeterSSG 101 dBm 445.000 MHz USA-1 Displayed frequencyPush and hold SQL key Transmitter Adjustment Dtmf DeviationHPF OFF LPF AUS, SEA Parts List =Surface mount Trimmer Ceramic ECUE1H121JCQ Transistor UN911D TX Coil Eljnd R10J 0.1U Themistor Ceramic ECUE1H060CCQ Ceramic ECUE1H390JCQ VCO Board Ceramic ECUE1H120JCQ Chassis Parts Mechanical Parts and DisassemblyAccessories VCO Unit MP29 C SEMI-CONDUCTOR Information Transistor and FET’SDiodes Board Layouts Logic UnitTOP View IC3 Bottom ViewIC1 GND Pset Ifin L912 RF UnitIC6 J4 to Logic unit J1 MP1 IC3IC2 OUT 12VCOOUT VCO BoardJ302 to RF unit VLVCO3 VHF GND VHVCO3 UVCO3 Uhfout GND 12VCO3 GND Q354 Block Diagram TX/RX Buff Mode Xtal BPF PDA2, CK AMPTX/RX Frequency ANT LPF HPF AMP MOD TX/RX Frequency ResetMode Xtal Initial BPF ANT Buff HPF LPF YGR Section Voltage Diagram Logic Unit DEC Ifout Filout Quad 2NDLOOscin Mixin Oscout GND Mixout REC VCC DET Ifin Rssi WFM NTCCF20124AH 473KCT TXC Clonein VCC VIN Cpuhv 12VCO COM2 ResetCOM3 COM2 Reset Power COM4 COM3 COM2 COM1 400M RF UnitVHF 1200M 1200MHz 50M00M 400MHz ENB VCC2 GND1PLST1 IN1 LOK GND2 Icom America Inc 5566I-S Icom Inc