Icom IC-703 Service Manual

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[Page 1] Icom IC-703

HF/ 50MHz ALL MODE TRANSCEIVER i703 SERVICE MANUAL ...

[Page 2] Icom IC-703

INTRODUCTION This service manual describes the latest service information for the IC-703 HF/50MHz ALL MODE TRANSCEIVER. DANGER NEVER connect the transceiver to an AC outlet or to a DC power supply that uses more than 16 V. This will ruin the transcei...

[Page 3] Icom IC-703

TABLE OF CONTENTS SECTION 1 SPECIFICATIONS SECTION 2 INSIDE VIEWS SECTION 3 CIRCUIT DESCRIPTION 3 - 1 RECEIVER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 - 1 3 - ...

[Page 4] Icom IC-703

1 - 1 SECTION 1 SPECIFICATIONS ■ GENERAL • Frequency coverage : Receive 0.030 – 60.000 MHz* Transmit 1.800 – 1.999 MHz* 3.500 – 3.999 MHz* 7.000 – 7.300 MHz* 10.100 – 10.150 MHz 14.000 – 14.350 MHz 18.068 – 18.168 MHz 21.000 ...

[Page 5] Icom IC-703

2 - 1 SECTION 2 INSIDE VIEWS • DISPLAY BOARD Sub CPU (IC6: HD6473847RH) +5V regulator Main dial Reset IC (IC4: S-80945CLMC-G7F) SW LED dimmer Q50: 2SB1132 Q51: 2SC4081 LCD driver (IC2: SED1522F0C) VR board Back light dimmer Q2: 2SB1132 Q3: 2SC...

[Page 6] Icom IC-703

• MAIN UNIT YGR amplifier (IC101: µPC2709T) 1st mixer (D701: HSB88WS) 1st IF amplifier (Q811: 2SK508) 1st IF filter (FI851: FL-348) 2nd mixer (D901: HSB88WS) 2nd IF filter (FI1501: CFWS455E) 2nd IF amplifier (Q1401: 3SK294) Noise blancer circuit ...

[Page 7] Icom IC-703

3 - 1 3-1 RECEIVER CIRCUITS 3-1-1 RF CIRCUIT (PA AND MAIN UNITS) HF/50 MHz RF filters pass only the desired band signals and suppress any undesired band signals. The HF/50 MHz RF circuit has 7 low-pass filters and 6 high-pass filters for specified ba...

[Page 8] Icom IC-703

3 - 2 The amplified signals are then applied to the 2nd mixer cir- cuit (D901). 3-1-5 2ND MIXER CIRCUIT (MAIN UNIT) The 2nd mixer circuit mixes the 1st IF signals and 2nd LO signal (64 MHz) to convert the 1st IF to a 2nd IF. The 1st IF signals from t...

[Page 9] Icom IC-703

3 - 3 3-1-9 AGC CIRCUIT (MAIN UNIT) The AGC (Automatic Gain Control) circuit reduces IF ampli- fier gain to keep the audio output at a constant level. The receiver gain is determined by the voltage on the AGC line (Q2503). The 2nd IF signal from the ...

[Page 10] Icom IC-703

3 - 4 3-1-13 AF SELECTOR SWITCH (MAIN UNIT) The AF signals from one of the detector circuits are applied to the AF selector switch (IC2301). IC2301 consists of dual 3-channel analog switches which are selected with a mode signal and the squelch contr...

[Page 11] Icom IC-703

3 - 5 IC1801 is a double balanced mixer IC and outputs a double side band (DSB) signal with –40 dB of carrier suppression. R1803 and R1807 adjust the balanced level of IC1801 for maximum carrier suppression. The resulting signal passes through a 9 ...

[Page 12] Icom IC-703

3 - 6 When the “FORL” voltage exceeds the “POCV” voltage, ALC bias voltage from IC2701 (pin 1) controls 1st and 2nd IF amplifiers (Q831, Q1401). This adjusts the output power to the level determined by the RF power setting until the “FORL�...

[Page 13] Icom IC-703

3 - 7 (2) ALC meter The ALC bias voltage from IC2701 pin 14 is applied to the main CPU (IC5901) via the “ALCV” signal line for indicating the ALC level. (3) SWR meter The “FORL” and “REFL” voltages are applied to the main CPU (IC5901) vi...

[Page 14] Icom IC-703

3 - 8 3-4-2 OUTPUT POWER DETECTING CIRCUIT (PA UNIT) The output power from the power amplifier (Q200, Q201) is divided at the C640 and C641. The divided voltage is applied to the power detecting circuit (D640) as detecting voltage. The detected volta...

[Page 15] Icom IC-703

3 - 9 Description Common 3 V converted from the HV line by the +3 regulator circuit (IC9901). Common 3 V converted from the 14V line by the +3 regulator circuit (IC9921). Common 5 V converted from the 14V line by the +5 regulator circuit (IC9941). Th...

[Page 16] Icom IC-703

3 - 10 40 41 42 43 46 47 49 50 51 52 53 55 56 57 58 59 61 65 66 67 72 73 80 Outputs strobe signal to the BFO’s DDS IC (IC9701). Outputs strobe signal to the DDS IC (IC9001) for main loop. Outputs strobe signal to the PLL IC (IC9101) for main...

[Page 17] Icom IC-703

3 - 11 85 86 88 89 90 91 92 93 94 95 96 97 99 Outputs the communicating signal with the main unit. Input port for the sub-dial’s B phase signal. Input port for [P.AMP/ATT] and [TUNER/CALL] keys. Input port for [MENU] and [F-1] keys. Input port for ...

[Page 18] Icom IC-703

4 - 1 4-1 PREPARATION BEFORE SERVICING ■ REQUIRED TEST EQUIPMENT DC power supply RF power meter (terminated type) Frequency counter RF voltmeter Standard signal generator (SSG) FM deviation meter Modulation analyzer Distortion meter Oscilloscope D...

[Page 19] Icom IC-703

4 - 2 4-2 PLL ADJUSTMENTS REFERENCE FREQUENCY VCO1 LOCK VOLTAGE VCO2 LOCK VOLTAGE ADJUSTMENT ADJUSTMENT ADJUSTMENT CONDITION MEASUREMENT VALUE POINT UNIT LOCATION UNIT ADJUST 1 2 1 1 • Display frequency: Any • Receiving • Display frequency: 29...

[Page 20] Icom IC-703

4 - 3 Reference frequency adjustment Reference frequency check point R9552 VCO2 lock voltage adjustment C9252 VCO1 lock voltage adjustment C9202 VCO1 and VCO2 lock voltage check point CP9151 CP9671 CP9611 • MAIN UNIT TOP VIEW ...

[Page 21] Icom IC-703

4 - 4 4-3 TRANSMITTER ADJUSTMENTS TRANSMIT PEAK POWER CARRIER SUPPRESSION TRANSMIT TOTAL GAIN OUTPUT POWER Id APC ADJUSTMENT ADJUSTMENT ADJUSTMENT CONDITION MEASUREMENT VALUE POINT UNIT LOCATION UNIT ADJUST 1 1 2 1 1 2 1 • Display frequency: 14.100...

[Page 22] Icom IC-703

4 - 5 Transmit total gain adjustment R833 Id APC adjustment R2765 Transmit peak power adjustment R1203 R1203 Carrier suppression adjustment R1807 R1803 Output power adjustment R2705 R2706 • MAIN UNIT TOP VIEW ...

[Page 23] Icom IC-703

4 - 6 TRANSMITTER ADJUSTMENTS (continued) FM DEVIATION AM MODULATION CW CARRIER LEVEL ADJUSTMENT ADJUSTMENT ADJUSTMENT CONDITION MEASUREMENT VALUE POINT UNIT LOCATION UNIT ADJUST 1 1 2 3 1 • Display frequency: 29.10000 MHz • Mode : FM • [RF PO...

[Page 24] Icom IC-703

4 - 7 FM deviation adjustment R2621 AM modulation adjustment R1811 R2618 R2707 CW carrier level adjustment R1853 • MAIN UNIT TOP VIEW ...

[Page 25] Icom IC-703

4 - 8 4-4 RECEIVER ADJUSTMENTS *This output level of the standard signal generator (SSG) is indicated as SSG’s open circuit. RECEIVER PEAK RECEIVER TOTAL GAIN NOISE BLANKER Maximum AF output level 30 dB of AF level differ- ence Adjust the maximum ...

[Page 26] Icom IC-703

4 - 9 Receiver peak adjustment L1101 L1102 L1201 Receiver total gain adjustment R1203 Noise blanker adjustment L1052 L1053 L882 L881 • MAIN UNIT TOP VIEW ...

[Page 27] Icom IC-703

4 - 10 4-5 SET MODE ADJUSTMENTS (No.1) ENTERING ADJUSTMENT SET MODE S-METER FILTER CALIBRATION POWER METER (14 MHz) POWER METER (50 MHz) ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION • Enter adjustment set mode: 1 Turn power OFF. 2 Terminate th...

[Page 28] Icom IC-703

4 - 11 ALC METER (HF bands) (50 MHz band) SWR METER HF ALC 50M ALC SWR 1 LOAD SWR 2 LOAD SET MODE ADJUSTMENTS (No.1)–Continued ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION • Connect an RF power meter to [ANT] con- nector. • Connect an audi...

[Page 29] Icom IC-703

4 - 12 4-6 PA UNIT ADJUSTMENTS IDLING CURRENT SWR DETECTION ADJUSTMENT ADJUSTMENT ADJUSTMENT CONDITION MEASUREMENT VALUE POINT UNIT LOCATION UNIT ADJUST 1 2 3 1 2 3 • Turn R159, R164 (on the PA unit) to maximum counterclockwise posi- tion. • Disp...

[Page 30] Icom IC-703

4 - 13 Idling current adjustment R159 R164 SWR detection check point CP41 SWR detection adjustment C561 J640 J642 J641 Antenna tuner adjustment plug replacement point • PA UNIT TOP VIEW ...

[Page 31] Icom IC-703

4 - 14 4-7 SET MODE ADJUSTMENTS (No.2) ENTERING ADJUSTMENT SET MODE ANTENNA TUNER TUNER RELAY ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION • Enter tuner adjustment set mode: 1 Turn power OFF. 2 Terminate the [REMOTE] jack with a 3.5(d) mm shor...

[Page 32] Icom IC-703

[DISPLAY UNIT][VR UNIT] R1 7210002780 VARIABLE RV-300 (RK0972210) 10KB/10KB R2 7210002940 VARIABLE TP96D231E20-20F-10KB-1897 J1 6510018890 S.CONNECTOR 52559-1390 S1 2220000540 SWITCH SW-162 (SSSS22-2-11) EP1 0910055780 PCB B 5913 J1 6510023460 S...

[Page 33] Icom IC-703

S.=Surface mount [DISPLAY UNIT][DISPLAY UNIT] R50 7030003800 S.RESISTOR ERJ3GEYJ 105 V (1 MΩ) R51 7030003420 S.RESISTOR ERJ3GEYJ 681 V (680 Ω) R52 7030003560 S.RESISTOR ERJ3GEYJ 103 V (10 kΩ) R53 7030003540 S.RESISTOR ERJ3GEYJ 682 V (6.8 k�...

[Page 34] Icom IC-703

S.=Surface mount [PA UNIT][PA UNIT] IC1 1180002010 S.REG BA08FP-E2 IC560 1110002700 S.IC NJM2904M-TE1 IC600 1140010671 S.IC ISPLSI2064VE-100LT100 I002 IC601 1130006800 S.IC TC7W08F (TE12L) IC640 1110001590 S.IC TA75393F (TP1) IC641 1130005640 S.IC ...

[Page 35] Icom IC-703

S.=Surface mount [PA UNIT][PA UNIT] L642 6180003310 COIL LR-436 L644 6200005010 S.COIL NL 252018T-100J L645 6200005010 S.COIL NL 252018T-100J L750 6110002750 COIL LA-459 L751 6110002760 COIL LA-460 L752 6110002770 COIL LA-461 L753 6110003700 COIL LA...

[Page 36] Icom IC-703

S.=Surface mount [PA UNIT][PA UNIT] R508 7030000210 S.RESISTOR MCR10EZHJ 39 Ω (390) R509 7030000210 S.RESISTOR MCR10EZHJ 39 Ω (390) R520 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R521 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R522 703...

[Page 37] Icom IC-703

S.=Surface mount [PA UNIT][PA UNIT] R813 7030003640 S.RESISTOR ERJ3GEYJ 473 V (47 kΩ) R814 7030003640 S.RESISTOR ERJ3GEYJ 473 V (47 kΩ) R815 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R816 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R817...

[Page 38] Icom IC-703

S.=Surface mount [PA UNIT][PA UNIT] C428 4030006880 S.CERAMIC C1608 JB 1H 472K-T C429 4030006880 S.CERAMIC C1608 JB 1H 472K-T C430 4030006880 S.CERAMIC C1608 JB 1H 472K-T C431 4030006880 S.CERAMIC C1608 JB 1H 472K-T C432 4030006880 S.CERAMIC C1608 JB...

[Page 39] Icom IC-703

S.=Surface mount [PA UNIT][PA UNIT] C713 4030006880 S.CERAMIC C1608 JB 1H 472K-T C714 4030006880 S.CERAMIC C1608 JB 1H 472K-T C715 4030006880 S.CERAMIC C1608 JB 1H 472K-T C716 4030006880 S.CERAMIC C1608 JB 1H 472K-T C717 4030006880 S.CERAMIC C1608 JB...

[Page 40] Icom IC-703

S.=Surface mount [MAIN UNIT][PA UNIT] W421 7030000010 S.JUMPER MCR10EZHJ JPW (000) W440 7030000010 S.JUMPER MCR10EZHJ JPW (000) W441 7030000010 S.JUMPER MCR10EZHJ JPW (000) W460 7030000010 S.JUMPER MCR10EZHJ JPW (000) W461 7030000010 S.JUMPER MCR...

[Page 41] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] Q1301 1590001870 S.TRANSISTOR DTA114EE TL Q1302 1590001870 S.TRANSISTOR DTA114EE TL Q1303 1590001870 S.TRANSISTOR DTA114EE TL Q1304 1590001870 S.TRANSISTOR DTA114EE TL Q1305 1560001260 S.FET 2SK3018 T106 Q1306 ...

[Page 42] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] D2704 1790001250 S.DIODE MA2S111-(TX) D2705 1160000140 S.DIODE DAP222 TL D2741 1160000140 S.DIODE DAP222 TL D2781 1790001330 S.ZENER MA8036-L (TX) D2782 1160000140 S.DIODE DAP222 TL D4001 1790001250 S.DIODE M...

[Page 43] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] L6804 6180003290 COIL BM27-400-6A L6828 6910003570 COIL 2943-666663 L6951 6180003290 COIL BM27-400-6A L6953 6180003290 COIL BM27-400-6A L6954 6140002220 COIL LR-270 (TR6X3X2 3A9) L6962 6180003290 COIL BM27-400-...

[Page 44] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] R842 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R843 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R844 7510001540 S.THERMISTOR NTCG16 4BH 332KT R851 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R852 70300...

[Page 45] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] R1725 7030003430 S.RESISTOR ERJ3GEYJ 821 V (820 Ω) R1751 7030003480 S.RESISTOR ERJ3GEYJ 222 V (2.2 kΩ) R1801 7030003440 S.RESISTOR ERJ3GEYJ 102 V (1 kΩ) R1802 7030003520 S.RESISTOR ERJ3GEYJ 472 V (4.7 k...

[Page 46] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] R2742 7030003560 S.RESISTOR ERJ3GEYJ 103 V (10 kΩ) R2743 7030003680 S.RESISTOR ERJ3GEYJ 104 V (100 kΩ) R2744 7030003800 S.RESISTOR ERJ3GEYJ 105 V (1 MΩ) R2745 7030003400 S.RESISTOR ERJ3GEYJ 471 V (470 ...

[Page 47] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] R6661 7030003640 S.RESISTOR ERJ3GEYJ 473 V (47 kΩ) R6662 7030003620 S.RESISTOR ERJ3GEYJ 333 V (33 kΩ) R6663 7030003580 S.RESISTOR ERJ3GEYJ 153 V (15 kΩ) R6664 7030003520 S.RESISTOR ERJ3GEYJ 472 V (4.7 ...

[Page 48] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] C8 4030011600 S.CERAMIC C1608 JB 1E 104K-T C9 4030011600 S.CERAMIC C1608 JB 1E 104K-T C12 4030006860 S.CERAMIC C1608 JB 1H 102K-T C13 4030006860 S.CERAMIC C1608 JB 1H 102K-T C102 4030011600 S.CERAMIC C1608 JB 1...

[Page 49] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] C884 4030011600 S.CERAMIC C1608 JB 1E 104K-T C885 4030006880 S.CERAMIC C1608 JB 1H 472K-T C886 4030007030 S.CERAMIC C1608 CH 1H 150J-T C887 4030006880 S.CERAMIC C1608 JB 1H 472K-T C888 4030006880 S.CERAMIC C160...

[Page 50] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] C2705 4030011600 S.CERAMIC C1608 JB 1E 104K-T C2781 4510004440 S.ELECTROLYTIC ECEV1HA010SR C2791 4030011600 S.CERAMIC C1608 JB 1E 104K-T C4001 4030011600 S.CERAMIC C1608 JB 1E 104K-T C5101 4030006880 S.CERAMIC ...

[Page 51] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] C7210 4550006080 S.TANTALUM TEMSVB2 1C 106M-8L C7211 4510004630 S.ELECTROLYTIC ECEV1CA100SR C7301 4510004630 S.ELECTROLYTIC ECEV1CA100SR C7302 4510004630 S.ELECTROLYTIC ECEV1CA100SR C7303 4510004630 S.ELECTROLY...

[Page 52] Icom IC-703

S.=Surface mount [MAIN UNIT][MAIN UNIT] J5101 6510023460 S.CONNETOR 08FMN-BMTTR-A-TBT J5901 6510022620 S.CONNECTOR 10FMN-BMTTR-A-TBT J6701 6510022650 S.CONNECTOR 18FMN-BMTTR-A-TBT J6751 6510022650 S.CONNECTOR 18FMN-BMTTR-A-TBT J6801 6510016170 CONNEC...

[Page 53] Icom IC-703

SECTION 6 MECHANICAL PARTS AND DISASSEMBLY 6 - 1 J1 6510000370 Antenna connector MR-DS 1 W7 8900011980 Cable OPC-1214 1 W8 8900011980 Cable OPC-1214 1 W9 8900011970 Cable OPC-1213 1 EP1 880001250 DSP unit UT-106 [Equipped version] only 1 SP1 25100009...

[Page 54] Icom IC-703

R1 7210002780 Variable resistor RV-300 (RK0972210) 1 R2 7210002940 Variable resistor 1 TP96D231E20-20F-10KB-1897 S1 2220000540 Switch SW-162 (SSSS22-2-11) 1 [VR BOARD] ORDER NO. REF. NO. DESCRIPTION QTY. MP1 8950004181 1691 contact base (A)-1 1 [JACK...

[Page 55] Icom IC-703

HF/50MHz TRANSCEIVER IC-703 AF RIT/ SUB MENU F-1 F-2 F-3 MODE BAND BAND TS DISPLAY LOCK RX TX M-CH PHONES TUNER P.AMP/ATT POWER SHIFT RF/SQL CH VFO A PO S1 5 53792040 10 60dB USB M1 SPL A/B A=B MP25 (C) MP20 (C) MP4 (C) + MP12 (C) + MP14 ...

[Page 56] Icom IC-703

...

[Page 57] Icom IC-703

1-1-32, Kamiminami, Hirano-ku, Osaka 547-0003, Japan S-13912HZ-C1 C 2003 Icom Inc. ...

[Page 58] Icom IC-703

6 - 4 MP12 (F)+MP21 (F) Unit abbreviations (C): CHASSIS UNIT (F): FRONT UNIT (D): DISPLAY BOARD (M): MAIN UNIT (P): PA UNIT (VR): VR BOARD (J): JACK BOARD EP1 (F) MP18 (F) MP1 (F) EP1 (F) MP26 (F) MP10 (F) MP11 (F) MP9 (F) W2 (F) MP3 (D) MP4 (D...

[Page 59] Icom IC-703

7 - 1 SECTION 7 SEMI-CONDUCTOR INFORMATION • TRANSSISTORS AND FET’S • DIODES B E C B E C B C E 2SA1162 GR 2SA1576A T106 R 2SB1132 T100 Q 2SB1132 T100 R 2SB1143 S 2SC4081 T106 R 2SC4213 B 2SC4405 3 TL 2SC4406 2SC4536 2SC4673 D TD 2SK21...

[Page 60] Icom IC-703

SECTION 8 BOARD LAYOUTS 8-1 DISPLAY BOARD • TOP VIEW POWER P.AMP/ATT TUNER/CALL RIT/SUB MENU F-1 F-2 F-3 PHONES LOCK DISPLAY TS MODE LRXD 17 28 to MAIN unit J5101 J1 LTXD 8V AFO GND MIC MICE PWRK 8 - 1 8-2 JACK BOARD • TOP VIEW ...

[Page 61] Icom IC-703

Q11 to JACK board 1 50 26 76 75 58 41 51 125 100 26 50 100 76 25 75 51 5V 14 to FRONT unit EP1 J5 MDBK MDAK GND 8VLM 1 to FRONT unit W2 8 J1 U/D AF PTT MICEL MICL GND SQLS DN1 to VR board J1 13 2 12 J3 AFL SQL AFV UP SFT GND AFL AF AF AFS AFS 5V PW...

[Page 62] Icom IC-703

1 1 4 58 25 75 76100 5026 1 1 1 10 20 11 12 24 13 4 58 51 1 8 8 1 5 8 4 1 14 6 10 5 1 4 8 5 1 14 85 8 5 5 4 16 9 15 10 6 64 13 1 4 8 5 to PA unit J100 PA I P3P2 to PA unit J300 RX P5P4 START 1 to PA unit J1 17 218 J6701 TPWR POWS GND 14V 14V GND T8V ...

[Page 63] Icom IC-703

1 8 16 9 1 10 6 1 5 7 14 8 1 4 8 5 1 1 1 1 8 16 9 1 1 1 7 14 8 8 16 9 7 14 8 7 14 8 7 14 8 7 14 8 1 1 4 8 5 8 4 1 5 7 14 8 6 10 5 1 8 16 9 1 1 7 14 8 1 12 24 13 16 9 1 8 • BOTTOM VIEW (MAIN UNIT) 8 - 4 ...

[Page 64] Icom IC-703

1 14 85 100 5051 25 26 76 75 85 1 1 1 4 8 5 4 85 4 GND to DC power HV to MAIN unit J2 PA I P2P3 to MAIN unit J1 RX P4P5 ANT CHASSIS J1 GND 117 218 to MAIN unit J6751 J41 TSWL TPHK REFL GND MCK3 PWRS TOE IDH TGK TPZS TPZL FORL DRES MDT3 TDTS IDL GND S...

[Page 65] Icom IC-703

• BOTTOM VIEW (PA UNIT) 8 - 6 ...

[Page 66] Icom IC-703

SECTION 9 BLOCK DIAGRAM ANTENNA MA732 D560/D561 RL641 SWR DET ATT RL640 AMP AMP RL401 RL421 RL441 RL461 RL481 RL501 RL521 RL400 RL420 RL440 RL460 RL480 RL500 RL520 LPF LPF LPF LPF LPF LPF LPF PWR AMP DRIVE AMP YGR AMP RL250 LPF HPF ATT LPF D102 D303...

[Page 67] Icom IC-703

SECTION 10 WIRING DIAGRAMS MAIN DIAL SQLS GND MICL MICEL PTT AF U/D 8VLM J1 J7J8 5V MDBK MDAK GND DN AFL AFL AF SQL AF AFV AFS UP AFS SFT 5V GND LRXD LTXD 8V AFO GND MIC MICE PWRK AFS NC PHNK AFLS GND J2 PHONES J5 J3 W1 (FRONT) MP19 J1 DN AFL AFL AF...

[Page 68] Icom IC-703

SECTION 11 VOLTAGE DIAGRAMS 11-1 FRONT UNIT 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 1...

[Page 69] Icom IC-703

11-2 MAIN UNIT 14V J1 5V W1 W3 W5 C7 0.1 R1 100 D3 MA77 R2 330 C8 0.1 D2 MA77 D1 MA77 R3 56 C6 0.1 R6 220k C5 0.1 C9 0.1 R4 220k R5 220 Q417 2SK3018 R11 47 Q1 DTA114EE Q4 2SK3018 Q2 DTA114EE Q101 XP4311 1 2 34 5 6 R104 10 C102 0.1 J2 R102 18 R101 27...

[Page 70] Icom IC-703

BUS LINE1 BUS LINE3 3V 14V 5V 8V T8L T8V MAIN UNIT (1) a L701 LR-317 EP801 R801 1k L801 0.27µ C801 0.001 C802 18p D701 HSB88WS C704 5p 3 1 25 4 6 Q652 XP4311 P5V Q753 2SK3018 Q752 DTA114EE R759 47k R758 1k SLOS b c d Q751 2SC4673 R754 4.7 C752 0.001...

[Page 71] Icom IC-703

BUS LINE1 R8L 14V 5V 8V T8L T8V R8V BUS LINE3 3V VCC2 IN+ IN- OUT GND VCC VCAOUT CTL VCAIN NC IC1601 M5282FP 1 2 3 4 56 7 8 9 10 IC1602 TC4W53F 5 6 7 81 2 3 4 COMS R1611 47k C1606 0.1 C1607 1 C1608 10 R1606 47k C1610 10 MIGV C1609 0.1 R1609 6.8k AMOD...

[Page 72] Icom IC-703

IC5901 M30620MCM-1W4GP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79...

[Page 73] Icom IC-703

BUS LINE1 14V 5V 8V HV BUS LINE3 BUS LINE5 VCC 3V 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 Y0 Y2 Y Y3 Y1 INH VEE VSS VDD X2 X1 X X0 X3 A B IC5601 BU4052BCF SML C5604 0.0047 TSWL C5603 0.0047 REFL C5602 0.0047 C5610 0.22 R5604 1k MPXY R5601 1k D5601 1SS...

[Page 74] Icom IC-703

J6701 START KEY TPWR 3V POWS GND GND NC 14V 14V 14V NC GND NC T8V 8V NC HV R6704 1k R6703 1k R6702 1k R6701 1k C7373 0.0047 ESPO ISPO ESPE J7371 J7372 J7121 C7121 0.1 ESPE ESPO BUS LINE1 14V 5V 8V T8L HV BUS LINE3 3V 1 2 3...

[Page 75] Icom IC-703

11-3 PA UNIT _F3S _F3R R448 39 F3S_ F3R_ R449 39 C445 100p _F7R _F7S R528 39 F7S_ F7R_ R529 39 C525 9p _F6R _F6S R508 39 F6S_ F6R_ R509 39 C503 27p _F4R _F4S R468 39 F4S_ F4R_ R469 39 C463 33p _F5R _F5S R488 39 F5S_ F5R_ R489 39 C483 39p _F2R _F2S R...

[Page 76] Icom IC-703

BUS LINE1 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 321 45 BUS LINE1 IT8V RL IT3V IT8V IT3V IT8V 4 8 7 6 5 1 2 3 IC560 NJM2904M - + + - b R571 100 a C56...

[Page 77] Icom IC-703

11 - 11 BUS LINE1 I/057 I/058 I/059 NC I/060 I/061 I/062 I/063 NC Y0 RESET VCC G0E1 GND BSCAN TDI/IN0 I/00 I/01 I/02 I/03 NC I/04 I/05 I/06 NC I/07 I/08 I/09 I/010 I/011 NC I/012 I/013 I/014 I/015 VCC TMS/IN1 NC GND I/016 I/017 I/018 I/019 NC I/020 ...