Page 2
8. READ the instructions of the test equipment throughly before connecting it to the transceiver. Icom, Icom Inc. and the Icom logo are registered trademarks of Icom Incorporated (Japan) in Japan, the United States, the United Kingdom, Germany, France, Spain, Russia and/or other countries.
Page 5
SECTION 2. INSIDE VIEWS • LOGIC UNIT DSC SIGNAL LINE SW (IC3) BEEP/DSC ENCODE SIGNAL BUFFER (IC2) +3.3 V REGULATOR DSC DECODER (IC4) (IC11) DATA LINE BUFFER (TXD) (IC6) RESET IC (IC10) NMEA LINE BUFFER (IC12) DATA LINE BUFFER (RXD) CI-V INTERFACE (IC7) (IC5)
Page 6
• MAIN UNIT (TOP VIEW) +5 V REGULATOR (IC512) AF POWER AMP (IC701) D/A CONVERTER (IC514) AF AMP (IC515) TX/RX AF LINE SW (IC901) TX/RX AF LINE SW (IC904) PLL IC AF LPF (IC101) (IC905) YGR AMP REFERENCE FREQUENCY (Q13) OSCILLATOR TX POWER AMP (X101)
Page 7
• MAIN UNIT (BOTTOM VIEW) AF PRE-AMP (IC702) +3 V REGULATOR (IC511) AF MUTE SW (IC703) AF MUTE SW (IC704) MIC AMP (IC513) AF MUTE SW (IC502) +1.1 V REGULATOR EXPANDER (IC903) (IC802) EXPANDER (IC801) NOISE CANCELING LSI (IC903) AF MUTE SW (IC503) AF BPF/MIC AMP (IC506)
Page 8
SECTION 3. DISASSEMBLY INSTRUCTION 1. Removing the FRONT UNIT 2. Removing the MAIN UNIT 1) Remove 6 screws from the rear. 1) Remove 6 screws from the rear. 2) Disconnect the fl at cable and inline cable from the 2) Remove the case from the chassis. LOGIC UNIT.
Page 9
2. Removing the MAIN UNIT (Continued) 5) Remove 7 screws from the top of MAIN UNIT. 6) Unsolder 2 points at the antenna connector. 7) Remove the MAIN UNIT from the chassis. UNSOLDER Solder remover (Top view) MAIN UNIT MAIN UNIT MAIN UNIT Chassis Screw x7...
Page 10
SECTION 4. CIRCUIT DESCRIPTION 4-1 RECEIVE CIRCUITS RF CIRCUITS (MAIN UNIT) 1ST IF CIRCUITS FOR CH70 (MAIN UNIT) The RX signal from the antenna is passed through the LPF The RX signal from the RF circuits is applied to the 1st IF (L21, L22, and C114–C116), ANT SW (D16), attenuator (D19, mixer (Q302), and mixed with the 125.649 MHz 1st LO signal R96) and BPF (L201, C201 and C202), and then applied to...
Page 11
RX AF CIRCUITS (MAIN UNIT) • When the AF signal is output to the optional COM- The demodulated AF signal from the AF SW (IC504B) MANDMICIV™ is passed through the BPF (IC506B, IC506C) and AF SW The RX AF signal from the AF SW (IC904, pins 1, 7) is passed (IC901, pins 7, 1), and then applied to the noise canceller IC through the AF MUTE SW (IC503A, pins 2, 1) and amplifi...
Page 12
TX AMP CIRCUITS (MAIN UNIT) 4-2 TRANSMIT CIRCUITS The TX signal is amplifi ed by the YGR (Q13) and power TX AF CIRCUITS (MAIN UNIT) AMP (IC1), and then passed through the LPF (L2, C111 and The AF signal from the microphone (MIC signal) is passed C112), TX output power detector (D12 and D13), ANT SW through the MIC mute SW (IC502A, pins 1, 2), and then ap- (D14), and two LPF (L21, L22, and C114–C116), before be-...
Page 13
4-3 FREQUENCY SYNTHESIZER (MAIN UNIT) • VCO • PLL The VCO (Q3, Q4, and D1–D3) generates both 1st LO signal A portion of VCO output signal is passed through two buffers for MAIN channels and the TX signal. (Q5 and Q6), and then fed back to the PLL IC (IC101, pin The output of buffer (Q7) is used as the TX or RX LO signal.
Page 14
4-5 PORT ALLOCATIONS • CPU (LOGIC UNIT: IC1) LINE LINE DESCRIPTION DESCRIPTION NAME NAME 87– LCD driver (LOGIC UNIT: DS1) con- [Y] key input. DB2–DB7 trol signal. L=Pushed. LCD driver (LOGIC UNIT: DS1) write [Z] key input. mode switch. L=Pushed. Rotary encoder pulse input (phase- [ ] key input.
Page 15
SECTION 5. PARTS LIST [MAIN UNIT] [MAIN UNIT] PARTS PARTS DESCRIPTION DESCRIPTION LOCATION LOCATION 1150002470 IC RA33H1516M1-225 6200013760 S.COI MLK1005S82NJT 73.7/17.9 IC201 1110007320 S.IC NJM2591V-TE1-#ZZZB 91.4/14.3 6200013750 S.COI MLK1005SR10JT 64.4/49.0 IC202 1110006490 S.IC LMV321IDCKR 97.0/18.6 6200010770 S.COI C2520C-R68G-A 92.4/45.2 IC301 1110007320 S.IC NJM2591V-TE1-#ZZZB 111.2/14.3...
Page 16
[MAIN UNIT] [MAIN UNIT] PARTS PARTS DESCRIPTION DESCRIPTION LOCATION LOCATION R116 7410001150 S.ARR EXB28V471JX 57.9/14.8 R534 7030009140 S.RES ERJ2GEJ 272 X (2.7K) 35.3/28.4 R117 7030005050 S.RES ERJ2GEJ 103 X (10K) 69.8/11.8 R535 7030005090 S.RES ERJ2GEJ 104 X (100K) 33.4/23.0 R118 7030010040 S.RES ERJ2GEJ-JPW 68.5/12.2 R537...
Page 23
[DIAL UNIT] ORDER DESCRIPTION QTY. 2250000730 TP90N245AE20PY-14.5F-3338 W1** 8900020410 OPC-2217 [CONNECT UNIT] ORDER DESCRIPTION QTY. 6510022440 LTW-8MP-C NUTGASKET <LIA> 6510025142 10FLT-SM2-TB (LF) (SN) (M) [VCO UNIT] ORDER DESCRIPTION QTY. 6910003831 IMSA-9230B-1-04Z003-PT1 6910003831 IMSA-9230B-1-04Z003-PT1 8510020510 3338 VCO CASE Y1269 8510020520 3338 VCO COVER Y1270 [ACCESSORIES] ORDER DESCRIPTION...
Page 24
MP16(C)x6 MP17(C)x6 MP15(C)x7 MP18(C) MP10(C) MP1(C) J1(CO) MP9(C) W1(C) MP4(C) MP3(C) MP14(C) J1(C) J1(C) CONNECT UNIT MP1(V) MP2(M) MP6(C) MAIN UNIT MP5(C) MP12(C) MP13(C)x2 MP16(F)x4 MP7(C) MP1(L)x2 MP22(F) W2(C) MP11(C) DS1(L) MP8(C) MP10(F) SP1(F) MP21(F) Abbreviation: (C): CHASSIS parts MP?(?) (L): LOGIC UNIT LOGIC UNIT (M): MAIN UNIT...
Page 25
The combination of top side and bottom side of this SECTION 7. BOARD LAYOUTS • LOGIC UNIT (TOP VIEW) RIGHT LEFT DOWN MENU DIST CH16 • CONNECT UNIT (TOP VIEW) • DIAL UNIT (TOP VIEW) 7 - 1...
Page 26
The combination of top side and bottom side of this • LOGIC UNIT (BOTTOM VIEW) LEFT RIGHT IC11 (CHASSIS) DOWN R101 (FRONT) B7572D MENU C104 R103 R108 EP11 C108 C105 C112 (FRONT) C111 C166 C162 C165 R115 DIST IC10 CH16 •...
Page 27
The combination of top side and bottom side of this • MAIN UNIT (TOP VIEW) D601 C115 C113 D504 D503 C503 C131 C501 C121 C502 B7571D C138 C508 C122 C132 • VCO UNIT R205 C203 C143 L201 C611 (TOP VIEW) C136 C125 C512...
Page 28
The combination of top side and bottom side of this • MAIN UNIT (BOTTOM VIEW) R504 R505 R503 R502 R501 R506 C605 IC511 C604 • VCO UNIT C602 L301 C924 C914 C603 C620 C302 C301 (BOTTOM VIEW) C913 Q511 C303 R906 R911 C911...
Page 30
SECTION 9. BLOCK DIAGRAM JTBM450CX70 FI204:LTWC450E1 MAIN UNIT X201 HM-196 CERAMIC WDECV MICI N I C201:NJM2591V FI202:FL-450 D 19:HVD144A Q 701:KTC4075 FI203:FL-451 (#01,02,10,20) NOISEV AM P MAINDET 2ND IF 2N D XTAL AM P BP F Q202: IC202:LMV321DCK 3SK293 Q 203:KTC4080 21.7MHz FI201: Q201:3SK294...
Page 33
• MAIN UNIT (2/2) RX:12.00V TX:11.54V RX:5.02V KTA2015 TX:4.97V RX:0V TX:4.84V C113 CP15 0.68U RN752 0.001 35.0N 35.0N to ANT CP16 VCO UNIT RF LO 41.0N HVD144A (11-4) LDTC144EE 2SC4226 C127 HVD144A LDTC144EE 35.0N 0.001 PLL LO T5VSO RX:3.27V TX:0V KTA2015 NJM2730F LDTC114EE...
Page 34
• VCO UNIT RX:4.99V RX:5.02V TX:4.89V TX:4.97V RX:2.41V TX:2.45V HVB350BYPTL RFLO HSC277TRF RX:0V PLLLO TX:3.94V LDTC144EE 2SC4226 KTC4080 HSC277TRF LDTA144EE 100k KTC4080 2SC4226 1.5P KTC4080 SHIFT MODC RX:2.89V 100k 100k TX:2.92V *: Refer to the PARTS LIST for the value and name of component. 10 - 4...
Page 42
July 2012 [MAIN UNIT] [LOGIC UNIT] PARTS PARTS DESCRIPTION DESCRIPTION LOCATION LOCATION C932 4030018080 S.CER C1005 JB 1H 182K-T 59.1/28.6 1140016241 S.IC STM32F100ZET6B(FX3338A1) C933 4030020010 S.CER C1005 CH 1H 271J-T 60.3/28.1 AMSC [USA] B 79.0/30.0 C934 4030016790 S.CER C1005 JB 1E 103K-T 60.2/23.3 1140016241 S.IC STM32F100ZET6B(FX33381)
Page 43
July 2012 [LOGIC UNIT] [LOGIC UNIT] PARTS PARTS DESCRIPTION DESCRIPTION LOCATION LOCATION 7030005530 S.RES ERJ2GEJ 100 X (10) 38.3/40.4 4030020300 S.CER GRM21BB31C475KA87L 38.8/8.8 7030005090 S.RES ERJ2GEJ 104 X (100K) 108.2/27.5 4030017460 S.CER C1005 JB 1H 102K-T 40.3/8.9 7030005170 S.RES ERJ2GEJ 474 X (470K) 35.3/39.8 4030016790 S.CER C1005 JB 1E 103K-T 38.4/11.6...
Page 44
July 2012 [CONNECT UNIT] [VCO UNIT] PARTS PARTS DESCRIPTION DESCRIPTION LOCATION LOCATION 4030016790 S.CER C1005 JB 1E 103K-T 2.1/11.9 1590004070 S.TRA LDTC144EET1G <SLVJ> 13.4/9.3 1530002921 S.TRA 2SC4226-T1 Y25 (R25) 11.9/2.8 1530002921 S.TRA 2SC4226-T1 Y25 (R25) 18.6/2.3 6510022440 CON LTW-8MP-C NUTGASKET <LIA> 1530003950 S.TRA KTC4080 Y-RTK/P 7.1/6.9...
Page 45
July 2012 The combination of top side and bottom side of this SECTION 7. BOARD LAYOUTS • LOGIC UNIT (TOP VIEW) RIGHT LEFT DOWN MENU DIST CH16 • CONNECT UNIT (TOP VIEW) • DIAL UNIT (TOP VIEW)
Page 46
July 2012 The combination of top side and bottom side of this • LOGIC UNIT (BOTTOM VIEW) LEFT RIGHT IC11 DOWN (CHASSIS) R101 (FRONT) B7572D MENU C104 R103 R108 EP11 C108 C105 C112 (FRONT) C111 C166 C162 C165 R115 DIST IC10 CH16 •...
Need help?
Do you have a question about the IC-M424 and is the answer not in the manual?
Questions and answers