Icom IC-M88 Service Manual
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Icom IC-M88 Service Manual

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VHF MARINE TRANSCEIVER
iC- m88

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Summary of Contents for Icom IC-M88

  • Page 1 VHF MARINE TRANSCEIVER iC- m88...
  • Page 2 INTRODUCTION This service manual describes the latest service information for the IC-M88 VHF MARINE TRANSCEIVE R at the time of publication. Model Version Symbol Battery pack FM I / S BP-227 U.S.A. IC-M88 USA-1 BP-227FM BP-227 S.E. Asia To upgrade quality, all electrical or mechanical parts and inter- nal circuits are subject to change without notice or obligation.

  • Page 3: Table Of Contents

    TABLE OF CONTENTS 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 ..................
  • Page 4 SECTION 1 SPECIFICATIONS GENERAL • Frequency coverage : TX: 156.025–157.425 MHz, RX: 156.050–163.275 MHz [MARINE] TX/RX: 146.000–174.000 MHz [LMR] • Number of free channels : 22 channels • Type of emission : 16K0G3E (Wide; 25 kHz) [MARINE] 16K0F3E (Wide; 25 kHz), 8K50F3E (Narrow; 12.5 kHz) [LMR] : SMA (50 Ω) •...
  • Page 5 VHF MARINE CHANNEL LIST Channel No. Frequency (MHz) Channel No. Frequency (MHz) Channel No. Frequency (MHz) Transmit Receive Transmit Receive Transmit Receive 156.050 160.650 157.050 157.050 156.675 156.675 156.050 156.050 157.100 161.700 156.725 156.725 156.100 160.700 157.100 157.100 156.875 156.875 156.150 160.750 157.150...
  • Page 6 SECTION 2 INSIDE VIEWS • LOGIC UNIT Bottom view *: Located in another side of this point. AF mute circuit Q441* : 2SC4116 Q442* : CPH3403 Q443 : CPH3403 IN/EXT microphone switch Q444 : DTC144EU (Q461, Q462: UN911H) EEPROM Microphone amplifier (IC591*: HN58X2416TI) (IC471: NJM2904V) AF mute...
  • Page 7 SECTION 3 DISASSEMBLY INSTRUCTIONS 1. Removing the chassis panel q Remove nut (2 × 8 mm, black) and 3 screws w Unscrew 2 screws (2 × 4 mm, black) from the chassis. e Take off the chassis in the direction of the arrow. NOTE: * Tighten the screws in order of a number (q–y) when assembling.

  • Page 8: Circuit Description

    SECTION 4 CIRCUIT DESCRIPTION The 1st IF signal is applied to a 2nd mixer section of the 4-1 RECEIVER CIRCUITS FM IF IC (IC231, pin 16). The signal is then mixed with a 4-1-1 ANTENNA SWITCHING CIRCUIT 2nd LO signal for conversion into a 450 kHz 2nd IF signal. (MAIN UNIT) The antenna switching circuit functions as a low-pass filter IC231 contains the 2nd mixer, limiter amplifier, quadrature...

  • Page 9: Transmitter Circuits

    4-1-5 SQUELCH CIRCUIT 4-2-2 MODULATION CIRCUIT (MAIN UNIT) The modulation circuit modulates the VCO oscillating signal (MAIN AND LOGIC UNITS) (RF signal) using the microphone audio signals. The noise squelch circuit cuts out AF signals when no RF signals are received. By detecting noise components in the The audio signals “MOCON”...

  • Page 10: Pll Circuits

    4-4 POWER SUPPLY CIRCUITS 4-3 PLL CIRCUIT (MAIN UNIT) VOLTAGE LINES 4-3-1 GENERAL The PLL circuit provides stable oscillation of the transmit LINE DESCRIPTION frequency and receive 1st LO frequency. The PLL output The voltage from the attached battery pack. compares the phase of the divided VCO frequency to the reference frequency.
  • Page 11 4-5 PORT ALLOCATIONS 4-5-1 CPU (LOGIC UNIT; IC661) Port Port Description Description number name number name BEEP Outputs beep audio signals. Outputs scrambler mute signal for the STXMS AF mute circuit (IC481, pin 3). Outputs strobe signals for the scrambler VSSTB Low : While scrambler is muting.
  • Page 12 4-5-2 EXPANDER IC (MAIN UNIT; IC341) CPU–Continued Port Port Description Description name number name number Outputs the AF mute switch (IC281, Input port for the [DOWN] key. DOWN pin 3) control signal. Low : While [DOWN] key is pushed. SRXMS Low : While the scrambler decording Input port for the [CH/WX] key.

  • Page 13: Adjustment Procedures

    ® ® • Microsoft Windows 95/98/ME 1. Connect IC-M88 and PC with the optional OPC-966 and the RS-232C cable. ® 2. Boot up Windows , and turn the transceiver power ON. 3. Click the program group ‘CS-M88 ADJ’ in the ‘Programs’...
  • Page 14 • CONNECTION Standard signal generator to the antenna connector 0.1 V to 32 mV ( 127 dBm to 17 dBm) Attenuator deviation meter 40 dB or 50 dB CAUTION: RF power meter DO NOT transmit while SSG is connected to the 0.1 10 W/50 antenna connector.
  • Page 15 • SCREEN EXAMPLE CS-M88 ADJ Rev.1.0 File Option COM 1: OPEN Connect Reload (F5) Disp para [A / D] [D / A] BATT : 120 : 78h : 7.53 V FRQCON : 127 : 7Fh : 2.49 V NOIS 59 : 3Bh : 1.16 V T1/POW : 92 : 5Ch : 1.80 V...

  • Page 16: Software Adjustment

    5-2 SOFTWARE ADJUSTMENT Select an operation using [ ↑ ] / [ ↓ ] keys, then set specified value using [←] / [→] keys on the connected computer keyboard. MEASUREMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE ADJUSTMENT UNIT ADJUSTMENT CONDITION UNIT LOCATION •...
  • Page 17 • MAIN UNIT TOP VIEW PLL lock voltage check point 5 - 5...
  • Page 18 SOFTWARE ADJUSTMENT – continued • Select an operation using [ ↑ ] / [ ↓ ] keys, then set specified value using [←] / [→] keys on the connected computer keyboard. • “SQUELCH LEVEL ADJUSTMENT” must be performed after “RX SENSITIVITY ADJUSTMENT” is finished. •...

  • Page 19: Parts List

    SECTION 6 PARTS LIST [VR UNIT] [LOGIC UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION Q552 1590001190 S.TR XP6501-(TX) .AB 13.3/23.7 R801 7210003130 VAR TP76N97N-13F-10KA-2497 Q553 1590000430 S.TR DTC144EUA T106 20.1/20.1 Q561 1510000670 S.TR 2SA1588-GR (TE85R) 22/16 Q651 1590001770 S.TR XP1213 (TX) 27.4/16.9 W801 8900011900 CBL...
  • Page 20 [LOGIC UNIT] [LOGIC UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION R553 7030003600 S.RES ERJ3GEYJ 223 V (22 kΩ) 12.4/19.4 C602 4030006980 S.CER C1608 CH 1H 070D-T 42.8/37.5 R561 7030003560 S.RES ERJ3GEYJ 103 V (10 kΩ) 20.1/16.1 C603 4030007070 S.CER C1608 CH 1H 330J-T 44.1/36.1 R562 7030003520 S.RES ERJ3GEYJ 472 V (4.7 kΩ)
  • Page 21 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION 6200008390 S.COL 0.25-1.9-9TL 44.1/24.7 1140005990 S.IC MB15A02PFV1-G-BND-ER 34/35 6200006980 S.COL ELJRE R10G-F 48.1/20.6 IC141 1110002750 S.IC TA75S01F (TE85R) 72.8/22.6 6200006980 S.COL ELJRE R10G-F 46.1/19.4 IC231 1110003200 S.IC TA31136FN (EL) 17.6/11.3 6200006980 S.COL ELJRE R10G-F 38.1/17.7 IC251...
  • Page 22 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION 7030003200 S.RES ERJ3GEYJ 100 V (10 Ω) R112 66.9/24.7 R291 7030003660 S.RES ERJ3GEYJ 683 V (68 kΩ) 25.4/15 R113 7030003520 S.RES ERJ3GEYJ 472 V (4.7 kΩ) 68.4/24.8 R292 7030003660 S.RES ERJ3GEYJ 683 V (68 kΩ) 28.2/17.6 R293 7030003660 S.RES ERJ3GEYJ 683 V (68 kΩ)
  • Page 23 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION C105 4030006860 S.CER C1608 JB 1H 102K-T 66.9/29 C247 4030006860 S.CER C1608 JB 1H 102K-T 17.4/11 C106 4030006860 S.CER C1608 JB 1H 102K-T 68.3/30.4 C251 4030006900 S.CER C1608 JB 1H 103K-T 5.3/17 C107 4030007050 S.CER C1608 CH 1H 220J-T...

  • Page 24: Mechanical Parts And Disassembly

    SECTION 7 MECHANICAL PARTS AND DISASSEMBLY [CHASSIS PARTS] [MAIN UNIT] ORDER ORDER QTY. QTY. DESCRIPTION DESCRIPTION MP41 8510013000 2336 VCO case Y534 6910014700 2600 ANT connector MP42 8510015430 1922 VCO cover (A)-1 7120000470 Jumper ERDS2T0 MP101 8510015250 2600 Shield case 7120000470 Jumper ERDS2T0 MP111...
  • Page 25 NOTE 1 NOTE 2 MP45 (C) SP1 (C) J41 (C) MP44 (C) NOTE 1 MP32 (C) NOTE3 MP33 (C) NOTE 3 MP42 (C) MP4 (C) MP31 (C) R801 (VR) MP43 (C) NOTE3 MP66 (C) VR UNIT MP6 (C) MP46 (C) MP54 (C) MP65 (C) DS681 (L) MP682 (L)

  • Page 26: Charger Unit

    • BC-152 CHARGER PARTS LIST ELECTRICAL PARTS ACCESSORY PARTS ORDER ORDER ORDER QTY. QTY. DESCRIPTION QTY. DESCRIPTION DESCRIPTION 1180000970 S.IC AN78L05M-(E1) 7030000010 S.JUMPER MCR10EZHJ JPW (000) 8810001470 Screw.5 x 30 SUS 1190001180 S.IC MM1332BFBE 7030000010 S.JUMPER MCR10EZHJ JPW (000) 1110005960 S.IC S-80833CNMC-B8S-T2 7030000010...
  • Page 27 SECTION SECTION 8 PARTS LIST SEMI-CONDUCTOR INFORMATION 8 - 1 TRANSISTORS AND FETs 8 - 2 DIODES • MAIN unit and LOGIC unit • MAIN unit and LOGIC unit 2SC4215 O/Y 2SA1588-GR 2SB1132 T100 Q 2SC4116 BL/GR 2SC4213-B 1SS375-TL 1SV245 1SV307 (TPH3) DAN222TL HVC350BTRF...

  • Page 28: Vr Unit

    SECTION 9 BOARD LAYOUTS 9 - 1 CHARGER UNIT (BC-152) • TOP VIEW • BOTTOM VIEW Horizontal Horizontal 9-2 VR UNIT 9-3 CONNECTOR UNIT • TOP VIEW • BOTTOM VIEW • TOP VIEW • BOTTOM VIEW to LOGIC UNIT J411 to MAIN UNIT J281 J851...
  • Page 29 9-4 MAIN UNIT • TOP VIEW The combination of this page and next page shows the unit layout in the same configuration as the actual P.C. Board. LOGIC UNIT J401 VOLIN to VR unit BTYPE W802 V5VS R5VS T5VS MICO SMICO W/NS TEMPV...

  • Page 30: Main Unit

    MAIN UNIT The combination of this page and previous page shows • BOTTOM VIEW the unit layout in the same configuration as the actual P.C. Board. Horizontal 9 - 3...
  • Page 31 9-5 LOGIC UNIT The combination of this page and next page shows the unit layout in the same configuration as the actual P.C. • TOP VIEW Board. Horizontal 9 - 4...

  • Page 32: Logic Unit

    LOGIC UNIT Horizontal • BOTTOM VIEW CP442 VOLIN BTYPE V5VS CP441 R5VS T5VS AFOUT MICO SMICO W/NS TEMPV LOINV J411 CDECV MAIN J401 UNLKI UNIT MODIN J351 CDTENC VSSTBO EXSTBO DASTBO to VR UNIT PLSTBO SDATAO SCLKO EXOEO WDECV RSSIV NOISV TDETV BEEPO...

  • Page 33: Block Diagram

    SECTION 10 BLOCK DIAGRAM Common Q47: XP6501 RIPPLE Transmit MAIN UNIT ANTENNA LVINV D91: MA77 Q91: Q101: Q111: Receive Q41: 2SC4226 D92: MA77 2SC5110 RD01MUS1 RD07MVS1 Q1: 2SK1829 Q3: 2SK880 Q61: 2SC4215 Q62: 2SC4215 D31-34: HVC350B TX/RX BUFF BUFF BUFF BUFF BUFF DRIVE...
  • Page 34 SECTION 11 VOLTAGE DIAGRAM Q47 XP6501 0.47µH V5FV V5FV PLL5V 150k LOCK: 4.85V 470p 4.78V UNLK: 0.50V VR UNIT 0.001 J281 VCO CASE R3 1k W802 MA2S111 2.2k UNLKI UNLKI IC1 MB15A02PFV-1 SCLK 0.47µH W802 HVC350B HVC350B PLLIN SDATA CLOCK DATA PLSTB PLSTB...
  • Page 35 R122 VCO CASE EP111 V5FV 0.001 TX: 3.51V TX: 4.86V C129 C128 1.5k 2SC4226 RX: 3.42V RX: 0.0V L124 470p 0.01 TX: 3.52V EP101 0.001 2.7 H D131 C131 L131 L132 C106 RX: 3.46V 80nH C114 C115 L112 1SV307 0.001 30nH 32nH CP131...
  • Page 36 LEDS1 LEDS1 LEDS2 LEDS2 DS681 CONT2 L2-0390TAY LOGIC UNIT W/NS W/NS CONT1 J401 DS651 DS653 VOLIN VOLIN FY1101F-TR SML-311YT C642 C641 LED ON: 5.00V 0.01 BTYPE BTYPE DS652 DS654 SEG9 VSS0 FY1101F-TR SML-311YT CPU5V SEG8 VDD0 S641 SEG7 CONT2 EVQ-PUL SEG6 R651 R652...
  • Page 37 E-mail : info@icomcanada.com Unit 9, Sea St., Herne Bay, Kent, CT6 8LD, U.K. Phone : +44 (01227) 741741 Fax : +44 (01227) 741742 Icom (Australia) Pty. Ltd. : http://www.icomuk.co.uk E-mail : info@icomuk.co.uk A.B.N. 88 006 092 575 290-294 Albert Street, Brunswick, Victoria, 3056, Australia Icom France S.a...
  • Page 38 S-13909MZ-C2-q 1-1-32, Kamiminami, Hirano-ku, Osaka 547-0003, Japan © 2002–2004 Icom Inc.

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