Icom IC-910H 8

8 - 2

CE1

2SK2855 2SK2973 2SK2975 3SK131 T2 LA 3SK177 T1B U73

3SK241 R CPH3404-TL DTA114 EE TL DTA114EUA T106 DTA144EUA T106

DTC114EUA T106 DTC114TUA T106 DTC144EUA T106 DTC144TU T107 FMW1 T148

NE34018 T1 RN2425 SRFJ7044 XP1113 XP4312

XP4315 XP4601

(Symbol: UT) (Symbol: K1) (Symbol: V12) (Symbol: U73)

(Symbol: DU) (Symbol: KD) (Symbol: 14) (Symbol: 16) (Symbol: 16)

(Symbol: 24) (Symbol: 04) (Symbol: 26) (Symbol: 06) (Symbol: W1)

(Symbol: V63) (Symbol: RE) (Symbol: SRFJ7044) (Symbol: 7L) (Symbol: 7T)

(Symbol: CB) (Symbol: 5C)

Contents

Main INTRODUCTION DANGER ORDERING PARTS REPAIR NOTES TABLE OF CONTENTS SECTION 1 SPECIFICATIONS GENERAL TRANSMITTER RECEIVER SECTION 2 INSIDE VIEWS 2-1 IC-910H MAIN ANDPLL UNITS PAUNIT 2-2 UX-910 (OPTIONAL UNIT) BOTTOM VIEW SECTION 3 DISASSEMBLYAND OPTION INSTRUCTIONS Opening the transceivers case CAUTION: UX-910 1200MHz BAND UNIT WARNING! WARNING! UT-102 VOICE SYNTHESIZER UNIT UT-106 DSP UNIT RECOMMENDATION: Installing 1st DSP unit (front panel side) Installing 2nd DSP unit (rear panel side) CR-293 HIGH STABILITY CRYSTAL UNIT SECTION 4 CIRCUIT DESCRIPTION 4-1 RECEIVER CIRCUIT 4-1-1 VHF TRANSMIT/RECEIVE SWITCHING CIRCUIT (PAUNIT) 4-1-2 VHF RF CIRCUIT (PAUNIT) 4-1-3 VHF 1ST MIXER CIRCUIT (PAUNIT) 4-1-6 10 MHz IF CIRCUIT (MAIN UNIT) 4-1-7 DEMODULATOR CIRCUIT (MAIN UNIT) 4-1-8 SQUELCH CONTROL CIRCUIT (MAIN UNIT) 4-1-9 SQUELCH CIRCUIT (MAIN UNIT) 4-1-10 AF AMPLIFIER CIRCUIT (MAIN UNIT) 4-2 TRANSMITTER CIRCUITS 4-2-1 MICROPHONE AMPLIFIER CIRCUIT (MAIN UNIT) 4-2-2 MODULATION CIRCUIT (MAIN UNIT) 4-2-3 CW KEYING CIRCUIT (MAIN UNIT) 4-2-4 TRANSMIT IF AMPLIFIER CIRCUIT (MAIN UNIT) 4-2-5 RF CIRCUIT (PAUNIT) 4-2-6 DRIVE AMPLIFIER CIRCUIT (PAUNIT) 4-3 PLL CIRCUITS 4-3-1 VHF PLL CIRCUIT (PLL UNIT) 4-3-2 UHF PLL CIRCUIT (PLL UNIT) 4-4 UX-910 (1200 MHz BAND UNIT) 4-4-1 ANTENNA SWITCHING CIRCUIT (for RX) 4-4-2 1200 MHz RF CIRCUIT (for RX) 4-4-3 1200 MHz 1ST/2ND MIXER CIRCUITS (for RX) 4-4-4 IF AMPLIFIER CIRCUIT (for TX) 4-4-5 DRIVE/POWER AMPLIFIER CIRCUITS (for TX) 4-4-6 PLL CIRCUITS SECTION 5 ADJUSTMENT PROCEDURES 4-1 PREPARATION BEFORE SARVICING IC-910H REQUIRED TEST EQUIPMENT CONNECTIONS 5-2 PLL ADJUSTMENTS 5-3 FREQUENCY ADJUSTMENT Page 5 - 4 5-4 RECEIVER ADJUSTMENTS Page RECEIVER ADJUSTMENTS (continued) 5 - 6 Page 5 - 8 5-5 TRANSMITTER ADJUSTMENTS Page 5 - 10 TRANSMITTER ADJUSTMENTS (continued) Page 5 - 12 5-6 SOFTWARE ADJUSTMENT CAUTION: NEVER 5 - 13 5 - 14 5 - 15 5 - 16 5 - 17 5 - 18 5-7 UX-910 ADJUSTMENTS Page 5 - 20 UX-910 ADJUSTMENTS (continued) Page [DISPLAYBOARD] 6-1 IC-910 [FRONT UNIT] 6 - 1 SECTION 6 PARTS LIST [DISPLAYBOARD] [DISPLAYBOARD][DISPLAYBOARD] 6 - 2 [DISPLAYBOARD][DISPLAYBOARD] 6 - 3 [FUNC BOARD] [VR-A BOARD] [VR-B BOARD] [PLL UNIT][RIT BOARD] 6 - 4 [JACK BOARD] [MIC BOARD] 6 - 5 6 - 6 6 - 7 [MAIN UNIT][PLL UNIT] 6 - 8 6 - 9 6 - 10 6 - 11 6 - 12 6 - 13 6 - 14 6 - 15 6 - 16 6 - 17 6 - 18 6 - 19 6 - 20 6 - 21 6 - 22 6 - 23 [DRV BOARD][PAUNIT] 6 - 24 [BARISTOR-A BOARD] [VARISTOR-B BOARD] [BARISTOR-C BOARD] 6-2 UX-910 [MAIN UNIT] 6 - 25 6 - 26 6 - 27 6 - 28 6 - 29 6 - 30 SECTION 7 MECHANICAL PARTS [FRONT UNIT] [COVER PARTS] [DISPLAYUNIT] [VR-A BOARD] [PA UNIT] [UX-910 CHASSIS PARTS] [PLL UNIT] [MAIN UNIT] [DRV BOARD] SECTION 8 SEMI-CONDUCTOR INFORMATION (Symbol: TGR) (Symbol: P2) (Symbol: IJ) (Symbol: K1) (Symbol: UP) 2SK882 GR 2SK1577 2 T7 2SK1740 2SK1829 2SK2854 2SA1162 GR 2SA1586 GR 2SA1588 GR 2SB1132 T100 R 2SB1133 R 2SB1201 S 2SC2712 BL 2SC2712 GR 2SC2714 O 2SC3102 8 - 2 2SK2855 2SK2973 2SK2975 3SK131 T2 LA 3SK177 T1B U73 XP4315 XP4601 3SK241 R CPH3404-TL DTA114 EE TL DTA114EUA T106 DTA144EUA T106 DTC114EUA T106 DTC114TUA T106 DTC144EUA T106 DTC144TU T107 FMW1 T148 DIODES NC 9-1 VR-A BOARD SECTION 9 BOARD LAYOUTS 9-3 RIT BOARD 9-2 VR-B BOARD Page < > < > Icom America Inc. Icom (Europe) GmbH Asia Icom Inc. Icom Spain S.L Icom (UK) Ltd. Icom France S.a Icom Canada Icom (Australia) Pty. Ltd. Icom New Zealand