Motorola IC-T81E, IC-T81A service manual VCO Board, J302 to RF unit, OUT 12VCOOUT, J301 to RF unit

Page 41

9-3 VCO BOARD

•TOP VIEW

10

J302 to RF unit

1

 

OUT

 

 

 

 

 

12VCOOUT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

J302

10

C374

R330

C331

R327

 

 

D312

1

C332

C312

R311

R318

R316

R317

R319

 

VLVCO3 VHF GND VHVCO3 UVCO3 UHFOUT GND

12VCO3 GND

Q351

 

R367

C368

C373

 

C389

R363

 

C361

C371

R369

C369

 

L331

Q350

R365

C366

L332

R368

C372

C329

R366

C370

 

 

 

R328

R322

R329

Q323

C330

 

 

R323

 

C327

C328

 

 

R326

 

 

 

 

 

C325

 

Q322

C326

 

R324

R325

Q321

 

C324

 

 

 

 

 

C310

 

C319

 

 

 

R312

R303

Q313

 

C316

 

 

 

 

 

 

Q312

R315

 

C307

 

 

 

 

C317

C309

 

R304

 

C315

 

 

 

 

 

 

 

R313

R314

 

 

 

C314

C313

Q311

C305

 

 

 

 

D311

 

 

 

 

 

 

R308

R302

 

 

 

 

 

 

C318

C320

C308

R307

 

Q302

 

R305

 

C306

 

Q301

 

J301 to RF unit

71

VLV GND ULV MOD SHIFT GND 12LV

R364

R361

C360

R362

C367

C365

 

R360

 

 

 

 

 

 

L330

 

D352

C362

D351

C364

 

L360

 

 

C363

 

 

 

 

 

 

 

7

L322

D322

C321

D321

C323

C322

L321

L312

 

C302

R301

C334

 

R306

C304

C333

 

D302

D301

L313

C311

L302

 

J301

L311

C301

 

 

L301

 

1

 

 

 

9 - 5

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Contents Multiband FM Transceiver Ordering Parts IntroductionRepair Notes Sample OrderTable of Contents General SpecificationsTransmitter Version 50 MHz 145 MHz 440 MHz 1200 MHz MHz RX onlyBand ReceiverWFM WFMLogic Unit Inside ViewsRF Unit CPURemoving the Chassis Panel Removing the Shield Plate Disassembly InstructionsRemoving the Logic Unit Removing the RF Unit Logic unitCircuit Description Antenna Switching Circuits RF UnitReceiver Circuits Duplexer Circuit RF Unit7 1ST Mixer Circuit RF Unit Transmitter Circuits APC Circuits RF Unit DRIVE/POWER Amplifier Circuits RF UnitMHz PA APC Control CircuitPLL Circuits Power Supply Circuits Voltage LineLine Description VCC1 I/O Expander IC RF Unit IC2 Port Allocations2 I/O Expander IC RF Unit IC3 Pin Port Description Number NameCPU Logic Unit IC1 Preparation Adjustment Procedures‘ Required Test Equipment ConnectionPLL Adjustment ULV RF Unit Bottom ViewVLV RF Unit TOP View 6MLVDial Receiver AdjustmentSensitivity VHFLogic Unit TOP View SSG MeterTop Push and hold MHz band 101 dBmPush and hold Displayed frequency445.000 MHz USA-1 SQL keyTransmitter Adjustment HPF OFF LPF DeviationDtmf AUS, SEA=Surface mount Parts ListTrimmer Ceramic ECUE1H121JCQ Transistor UN911D TX Coil Eljnd R10J 0.1U Themistor Ceramic ECUE1H060CCQ Ceramic ECUE1H390JCQ VCO Board Ceramic ECUE1H120JCQ Accessories Mechanical Parts and DisassemblyChassis Parts VCO UnitMP29 C Diodes SEMI-CONDUCTOR InformationTransistor and FET’S TOP View Board LayoutsLogic Unit IC1 Bottom ViewIC3 GND Pset IfinIC6 RF UnitL912 J4 to Logic unit J1IC2 MP1IC3 J302 to RF unit VCO BoardOUT 12VCOOUT VLVCO3 VHF GND VHVCO3 UVCO3 Uhfout GND 12VCO3 GNDQ354 Block Diagram TX/RX Frequency Mode Xtal BPF PDA2, CK AMPTX/RX Buff ANT LPF HPF AMPMode Xtal Initial BPF ResetMOD TX/RX Frequency ANT Buff HPF LPF YGRLogic Unit Section Voltage DiagramOscin Mixin Oscout GND Mixout REC VCC DET Ifin Rssi 2NDLODEC Ifout Filout Quad WFM NTCCF20124AH 473KCT TXCCOM3 COM2 Reset Power 12VCO COM2 ResetClonein VCC VIN Cpuhv COM4 COM3 COM2 COM1VHF RF Unit400M 1200M00M 50M1200MHz 400MHzPLST1 IN1 GND1ENB VCC2 LOK GND2Icom America Inc Icom Inc 5566I-S
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