Motorola IC-T81A, IC-T81E 9

9 - 6

•BOTTOM VIEW

C388

R374

Q354

Q353

L333

L337

L336

R371

C380 C378

C381

C384

R373

L338

L335

L334

C375

C376

R372

C387

R321

C386

C385

C383

C303

C382

C379

C377

Contents

Main INTRODUCTION DANGER ORDERING PARTS REPAIR NOTES TABLE OF CONTENTS MGENERAL MTRANSMITTER SECTION 1 SPECIFICATIONS MRECEIVER SECTION 2 INSIDE VIEWS ( ) SECTION 3 DISASSEMBLY INSTRUCTIONS SECTION 4 CIRCUIT DESCRIPTION 4-1 RECEIVER CIRCUITS 4-1-1 DUPLEXER CIRCUIT (RF UNIT) 4-1-2 ANTENNASWITCHING CIRCUITS (RF UNIT) 4-1-3 50 MHz BAND RF CIRCUIT (RF UNIT) 4-1-5 440 MHz BAND RF CIRCUIT (RF UNIT) 4-1-6 1200 MHz BAND RF CIRCUIT (RF UNIT) 4-1-7 1ST MIXER CIRCUIT (RF UNIT) 4-1-8 2ND IF AND DEMODULATOR CIRCUITS (RF AND LOGIC UNITS) 4-1-9 AF AMPLIFIER CIRCUIT (LOGIC UNIT) 4-2 TRANSMITTER CIRCUITS 4-2-1 MICROPHON AMPLIFIER CIRCUIIT (LOGIC UNIT) 4-2-2 MODULATION CIRCUIT (VCO AND RF UNIT) 4-2-3 DRIVE/POWER AMPLIFIER CIRCUITS (RF UNIT) 4-2-4 APC CIRCUITS (RF UNIT) 4-3 PLL CIRCUITS 4-3-1 50 MHz BAND PLL CIRCUIT (RF UNIT) VOLTAGE LINE 4-3-2 144 MHz BAND PLL CIRCUIT 4-3-3 440 MHz BAND PLL CIRCUIT 4-5 PORT ALLOCATIONS 4-5-3 CPU (LOGIC UNIT; IC1) - SECTION 5 ADJUSTMENT PROCEDURES + CAUTION: 5-1 PREPARATION 5-2 PLL ADJUSTMENT Page 5-3 RECEIVER ADJUSTMENT Page Page RECEIVER ADJUSTMENT (Continued) LOGIC UNIT TOP VIEW R733 5-4 TRANSMITTER ADJUSTMENT LOGIC UNIT TOP VIEW R322 R338 R325 TRANSMITTER ADJUSTMENT (Continued) SECTION 6 PARTS LIST 6 - 1 6 - 2 6 - 3 6 - 4 6 - 5 6 - 6 6 - 7 6 - 8 [VCO BOARD] 6 - 9 6 - 10 [VCO BOARD] [VCO BOARD] 7 - 1 SECTION 7 MECHANICAL PARTS AND DISASSEMBLY EP3 [ACCESSORIES] [VCO UNIT] [CHASSIS PARTS] LOGIC unit VCO unit RF unit SECTION 8 SEMI-CONDUCTOR INFORMATION 8 - 1 9 - 1 SECTION 9 BOARD LAYOUTS L702 R733 9-1 LOGIC UNIT DS1 S1 J4 9-2 RF UNIT 9 - 3 C961 40 21 DC-DC MP1 C842 C815 IC802 C86 9-3 VCO BOARD 9 - 6 VCO BOARD BUS TX COMMON RX SECTION 10 BLOCK DIAGRAM 10 - 1 Page VCO BOARD BUS 10 - 1 TX SECTION 10 BLOCK DIAGRAM Q307 Q304 IC201 TA7368F XP4315 SECTION 11 VOLTAGE DIAGRAM 11-1 LOGIC UNIT 4 3 11 - 1 COMPLETE VIEW A 64 Q XC6371A500PR B SECTION 11 VOLTAGE DIAGRAM 11-1 LOGIC UNIT 11 - 1 Q322 Q311 VCO BOARD RF UNIT 11-2 RF UNIT CHG + - 50MHz 3SK292 1200MHz 3SK291 SC5195 VCO BOARD RF UNIT 11-2 RF UNIT INTRODUCTION DANGER ORDERING PARTS REPAIR NOTES