This service manual describes the latest service information for the IC-T7H DUAL BAND FM Transceiver at the time of publication. 4 version of the IC-T7H have been designed. This serves manual cover each versions. SECTION 1 SPECIFICATIONS SECTION 2 INSIDE VIEWS SECTION 3 DISASSEMBLY INSTRUCTIONS SECTION 4 CIRCUIT DESCRIPTION 4 - 1 Receiver CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 1 4 - 2 Transmitter CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 2 4 - 3 PLL CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 3 4 - 4 Power Supply CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 4 4 - 5 OTHER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 4 4 - 6 PORT ALLOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 5 SECTION 5 ADJUSTMENT PROCEDURES 5 - 1 PLL AND Transmitter ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 - 1 5 - 2 Receiver ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 - 3 SECTION 6 PARTS LIST SECTION 7 MECHANICAL PARTS AND DISASSEMBLY SECTION 8 SEMI-CONDUCTOR INFORMATION SECTION 9 BOARD LAYOUTS 9 - 1 LOGIC UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 - 1 9 - 2 2F UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 - 3 9 - 3 1F UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 - 5 SECTION 10 BLOCK DIAGRAM SECTION 11 VOLTAGE DIAGRAM

IMPORTANT ... i EXPLICIT DEFINITIONS ... i CAUTIONS ... i UNPACKING ... ii TABLE OF CONTENTS ... iii 1PANEL DESCRIPTION ... 1 – 5 ■ Switches, controls, keys and connectors ... 1 ■ Function display ... 5 2BATTERY PACKS AND ACCESSORIES ... 6 – 9 ■ Battery pack charging ... 6 ■ Charging precautions ... 6 ■ About the battery pack ... 6 ■ Charging connections ... 7 ■ Battery case ... 8 ■ Accessory attachment ... 9 3BASIC OPERATION ... 10 – 14 ■ Power ON ... 10 ■ Setting a frequency ... 10 ■ Setting tuning steps ... 11 ■ Selecting a memory channel ... 12 ■ Lock function ... 12 ■ Receive and transmit ... 12 ■ Repeater operation ... 13 iii 4ADVANCED FUNCTIONS ... 15 – 22 ■ Memory/call channels ... 15 ■ DTMF memory operation ... 17 ■ Scan operation ... 18 ■ Subaudible tone operation ... 21 5OTHER FUNCTIONS ... 23 – 26 ■ Initial set mode ... 23 ■ Channel indication mode ... 26 ■ CPU resetting ... 26 6789TROUBLESHOOTING ... 27 OPTIONS ... 28 SPECIFICATIONS ... 29 MODE ARRANGEMENT ... 30 – 31