This service manual describes the latest information for the following transceivers at the time of publication. SECTION 1 SPECIFICATIONS .......................................................................................................... 1—1 SECTION 2 INSIDE VIEWS................................................................................................................. 2—1 SECTION 3 CIRCUIT DESCRIPTION ............................................................................................3-1-5 3-1 RECEIVER CIRCUITS ............................................................................................... 3—1 3-2 TRANSMITTER CIRCUITS ........................................................................................ 3—2 3-3 PLL CIRCUITS............................................................................................................. 3—3 3-4 LOGIC CIRCUITS ...................................................................................................... 3—3 3-5 OTHER CIRCUITS ...................................................................................................... 3—5 SECTION 4 ADJUSTMENT PROCEDURES .................................................................................4-1-4 4-1 PREPARATION BEFORE SERVICING ...................................................................... 4—1 4-2 PLL ADJUSTMENT...................................................................................................... 4—2 4-3 RECEIVER ADJUSTMENT ........................................................................................ 4—3 4-4 TRANSMITTER ADJUSTMENT ................................................................................. 4—3 SECTION 5 MECHANICAL PARTS AND DISASSEMBLY ...........................................................5-1-2 5-1 TRANSCEIVER .......................................................................................................... 5—1 5-2 ACCESSORIES .......................................................................................................... 5—1 SECTION 6 CONNECTOR ASSEMBLY ............................................................................................ 6—1 SECTION 7 PARTS LIST.................................................................................................................7-1-7 SECTION 8 BOARD LAYOUTS.......................................................................................................8-1-7 8-1 LOGIC UNIT................................................................................................................. 8—1 8-2 MAIN UNIT ................................................................................................................. 8—2 8-3 PLL-A UNIT ................................................................................................................. 8—4 8-4 IF UNIT ......................................................................................................................... 8—4 8-5 APC UNIT..................................................................................................................... 8—4 8-6 VCO UNIT..................................................................................................................... 8—5 8-7 MIC-AMP UNIT.............................................................................................................. 8—5 8-8 YGR UNIT..................................................................................................................... 8—6 8-9 A-BANDUNIT .............................................................................................................. 8—6 8-10 UT-51 TONE ENCODER UNIT ..................................................................................... 8—7 SECTION 9 OPTION UNITS ..........................................................................................................9-1-2 9-1 UT-50 TONE SQUELCH UNIT ..................................................................................... 9—1 9-2 UT-55 DTMF ENCODER/DECODER UNIT................................................................... 9—2 SECTION 10 VOLTAGE DIAGRAM.......................................................................................................10—1 SECTION 11 BLOCK DIAGRAM ..........................................................................................................11—1