Icom IC-F2721 Service Manual
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Icom IC-F2721 Service Manual

Icom IC-F2721 Service Manual

Uhf moble transceivers
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SERVICE
MANUAL
UHF MOBLE TRANSCEIVERS

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  • Page 1 SERVICE MANUAL UHF MOBLE TRANSCEIVERS...
  • Page 2 16 V. This will ruin the TRANSCEIVER at the time of publication. transceiver. 6 versions of the IC-F2721 have been designed. This service manual covers each version. DO NOT expose the transceiver to rain, snow or any liquids.

  • Page 3: Table Of Contents

    11-3 MAIN UNIT ............11-3 Icom, Icom Inc. and logo are registered trademarks of Icom Incorporated (Japan) in the United States, the United Kingdom, Germany, France, Spain, Russia and/or other countries.

  • Page 4: Specifications

    SECTION 1 SPECIFICATIONS IC-F2721/D, IC-F2821/D IC-F2710, IC-F2810 Measurement method EIA-152-C/204D or TIA-603 EN 300 086 [L] : 400.000–470.000 MHz [L] : 400.000–470.000 MHz Frequency coverage [H] : 450.000–512.000 MHz [H] : 480.000–520.000 MHz 8K10F1E/8K10F1D*/ 8K50F3E/14K0F3E/ Type of emission 8K50F3E/16K0F3E 11K0F3E/16K0F3E...

  • Page 5: Inside Views

    SECTION 2 INSIDE VIEWS • MAIN UNIT Top view Power amplifier IC29: RA30H4452M [H-25W] RA30H4047M [L-25W] RA55H4047M [L-45W] RA55H4452M [H-45W] AF amplifier APC amplifier (IC38: LA4425A) (IC37: TA75S01F) +5V regulator (Q31: 2SB1132, Mixer circuit Q32: XP6501) (D16: HSB88WSTR, L22, L23) Digital CPU (IC20: TX VCO circuit...
  • Page 6 • FRONT-A UNIT (IC-F2700 Series) Reset IC LCD driver Mic amplifier (IC2: S-80942CNMC) (IC7: SED1526F0A) (IC5: TC75S51F) Front CPU Backlight ALC amplifier Mic switch dimmer control (IC9: AN6123MS) (IC8: TC4W53F) (IC3: HD64F3687) Q3: 2SC4116 Q4: DTC114TU Q5: DTC114TU • FRONT-B UNIT (IC-F2800 Series) Backlight Mic switch Front CPU...

  • Page 7: Disassembly Instructions

    SECTION 3 DISASSEMBLY INSTRUCTIONS • REMOVING THE FRONT UNIT 2 Unscrew 4 screws, G and remove the shield cover H. 1 Unscrew 4 screws, A, then remove the bottom cover. w Unplug J1(B) and J6 (C). 3 Unsolder 3 points, I and 5 points J. 3 Unscrew 2 screws, D.

  • Page 8: Circuit Description

    SECTION 4 CIRCUIT DESCRIPTION 4-1 RECEIVER CIRCUITS 4-1-3 1ST MIXER AND 1ST IF CIRCUITS (MAIN UNIT) The 1st mixer circuit converts the received signals into fixed 4-1-1 ANTENNA SWITCHING CIRCUIT (MAIN UNIT) frequency of the 1st IF signal with the PLL output frequency. The antenna switching circuit functions as a low-pass filter By changing the PLL frequency, only the desired frequency while receiving and a resonator circuit while transmitting.
  • Page 9 A 2nd LO signal (45.9 MHz) is produced at the PLL circuit The power amplified AF signals are applied to the internal by tripling it’s reference frequency (X2: 15.3 MHz). speaker (IC-F2700 series only) that is connected to J6 via [EXT SP] jack (J5).

  • Page 10: Transmitter Circuits

    (Q23), drive (Q48) and power (IC29) amplifiers to obtain 45 (FRONT UNIT; IC8, pins 1, 6, 7) and are then applied to the W (IC-F2721/D/F2821/D; 25 W for IC-F2710/F2810) of RF ALC amplifier (FRONT UNIT; IC9) during digital mode oper- power.

  • Page 11: Pll Circuits

    4-3 PLL CIRCUITS A portion of the signal from the buffer amplifier (Q20) is fed back to the PLL IC (IC4, pin 6) via the buffer amplifier (Q19) 4-3-1 PLL CIRCUIT (MAIN UNIT) as the comparison signal. A PLL circuit provides stable oscillation of the transmit fre- quency and receive 1st LO frequency.

  • Page 12: Other Circuits

    4-5-2 DIGITAL MODE CIRCUIT (IC-F2721D/F2821D only) 4-5 OTHER CIRCUITS (1) WHILE RECEIVING 4-5-1 COMPANDER CIRCUIT (MAIN UNIT) A portion of the 2nd IF signal from the limiter amplifi er sec- IC-F2700/2800 series have compander circuit which can tion in the FM IF IC (IC12) output from pin 11 and is ap- improve S/N ratio and become wide dynamic range.

  • Page 13: Port Allocations

    4-6 PORT ALLOCATIONS 4-6-1 Main CPU (MAIN UNIT; IC23) Port Port Description Description number name number name I/O port for data signal to the D/A con- Outputs beep audio signals. BEEP DSDA verter (IC30 pin 6). Input por t for single tone decode Outputs strobe signals to the D/A con- SDEC signal from the base band IC (IC2,...
  • Page 14 4-6-2 FRONT CPU (FRONT UNIT; IC3) 4-6-4 D/A CONVERTER (MAIN UNIT; IC30) Port Port Description Description number name number name Input port for rest signal. Outputs the bandpass filters (D23, D26, D68, D69) tuning signal. KR0– I n p u t p o r t s fo r t h e 1 0 - k e y p a d . 19–22 (IC-F2800 series only) •...

  • Page 15: Adjustment Procedures

    SECTION 5 ADJUSTMENT PROCEDURES 5-1 PREPARATION When adjusting IC-F2721/D,F2710,F2821/D,F2810, the optional CS-F70/F1700 ADJ (Rev. 1.0 or later) ADJUSTMENT SOFTWARE and JIG CABLE (modifi ed OPC-1122 ; see illustration on page 5-3) are required. CLONING CABLE ▄ REQUIRED TEST EQUIPMENT EQUIPMENT...
  • Page 16 • CS-F70/F1700 ADJ'S SCREEN EXAMPLE NOTE: The above values for settings are example only. Each transceiver has its own specific values for each setting. !7 : Deviation (narrow) q: Reloads adjustment data o: Squelch level !8 : Deviation (wide) w: Transceiver's connection state !0 : Reference frequency !9 : Deviation (digital) e: Connected DC voltage measurement...
  • Page 17 SSG is connected to to the antenna connector the antenna connector. to an RS-232C port RS-232C cable (straight) to the MIC connector AC millivoltmeter IC-F2721/D JIG CABLE IC-F2821/D Audio generator IC-F2710 IC-F2810 • JIG CABLE Add a jumper wire here PTT switch...

  • Page 18: Lcd Contrast Adjustment

    5-2 LCD CONTRAST ADJUSTMENT MEASUREMENT ADJUSTMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST 1 • Operating CH. : CH 1 FRONT A/B C o n n e c t a d i g i t a l –2.0 V FRONT A/B CONTRAST multimeter or an oscillo-...

  • Page 19: Main Unit

    5-3 SOFT WARE ADJUSTMENT Select an operation using [↑] / [↓] keys, then set specifi ed value using [←] / [→] keys on the connected computer keyboard. MEASUREMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION PLL LOCK 1 • Operating CH. : CH 1 Check the "LVIN"...
  • Page 20 SOFTWARE ADJUSTMENT (Continued) Select an operation using [↑] / [↓] keys, then set specifi ed value using [←] / [→] keys on the connected computer keyboard. MEASUREMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION OUTPUT 1 • Operating CH. : CH 10 Rear Connect an RF power meter to 25.0 W [25W]...
  • Page 21 SOFTWARE ADJUSTMENT (Continued) Select an operation using [↑] / [↓] keys, then set specifi ed value using [←] / [→] keys on the connected computer keyboard. MEASUREMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION ±2.75 kHz 1 • Operating CH. : CH 7 DIGITAL Rear Connect a modulation ana-...
  • Page 22 SOFTWARE ADJUSTMENT (continued) • Select an operation using [↑] / [↓] keys, then set specifi ed value using [←] / [→] keys on the connected computer keyboard. MEASUREMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION NOTE: Adjust all the adjustment items as follows throughly in sequence. •...
  • Page 23 SECTION 6 PARTS LIST [FRONT-A UNIT] (for IC-F2700 series) [REPLACEMENT UNITS] ORDER ORDER NO. UNIT NAME DESCRIPTION LOCATION 0327810101 U F1721 #01 FRONT-A [F2721/D], [F2710] 7030005090 S.RES ERJ2GEJ 104 X (100 kΩ) 74.9/29.4 0327811102 U F1821 #11 FRONT-B [F2821/D], [F2810] 7030005090 S.RES ERJ2GEJ 104 X (100 kΩ) 75.8/29.6 7030005090 S.RES ERJ2GEJ 104 X (100 kΩ)

  • Page 24: Front-A Unit (For Ic-F2700 Series)

    [FRONT-A UNIT] (for IC-F2700 series) [FRONT-B UNIT] (for IC-F2800 series) ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION 4030018860 S.CER ECJ0EB0J105K 24.7/11.1 7030005530 S.RES ERJ2GEJ 100 X (10Ω) 83.8/20.8 4030017420 S.CER ECJ0EC1H470J 82.2/35.1 7030005090 S.RES ERJ2GEJ 104 X (100 kΩ) 56.2/21.1 4030017420 S.CER ECJ0EC1H470J 81/32.4 7030005090 S.RES ERJ2GEJ 104 X (100 kΩ) 62.2/29.6...

  • Page 25: Main Unit

    [FRONT-B UNIT] (for IC-F2800 series) [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION 4030017420 S.CER ECJ0EC1H470J 18.5/15.8 1110005340 S.IC NJM12902V-TE1 75.1/36.2 4030017460 S.CER ECJ0EB1E102K 31.8/15.3 1110006220 S.IC AK2346-E2 48.4/27.8 4030016790 S.CER ECJ0EB1C103K 27.8/17.7 1130010100 S.IC LMX2352TMX 73.1/64.7 4550006540 S.TAN ECST1CY475R 27.5/20.8 1130009700 S.IC LC73872M-TRM...
  • Page 26 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION 1590001190 S.TR XP6501-(TX) .AB 104.4/72.6 2020001780 S.CER CFWCA450KEFA-R0 1590001450 S.FET 2SJ144-GR (TE85R) 148.5/21.6 [F2721D], [F2821D] only 78.8/18.5 1540000550 S.TR 2SD1664 T100Q 101.2/81.2 2030000410 S.MLH FL-380 MFT46.3P 46.350 MHz 34.3/43.2 1590001050 S.TR DTC114TUA T106 104.4/76.2 2040001440 S.LC...
  • Page 27 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION 7030005210 S.RES ERJ2GEJ 822 X (8.2 kΩ) 49.2/32.9 R112 7030004980 S.RES ERJ2GEJ 101 X (100Ω) 7030005120 S.RES ERJ2GEJ 102 X (1 kΩ) 54.4/26.9 [F2721D], [F2821D] only 82.2/13.7 7030007300 S.RES ERJ2GEJ 332 X (3.3 kΩ) 54.1/16.2 R113 7030005070 S.RES ERJ2GEJ 683 X (68 kΩ)
  • Page 28 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION [F2721D], [F2821D] only 97.8/25.9 [F2721D], [F2821D] only 114.5/7.1 R172 7030005240 S.RES ERJ2GEJ 473 X (47 kΩ) R236 7030004980 S.RES ERJ2GEJ 101 X (100Ω) [F2721D], [F2821D] only 116.5/17.7 [F2721D], [F2821D] only 116.2/5.2 R173 7030010040 S.RES ERJ2GE-JPW...
  • Page 29 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION R321 7030010040 S.RES ERJ2GE-JPW 139.3/79.3 R430 7030009290 S.RES ERJ2GEJ 562 X (5.6 kΩ) 77.2/59.9 R322 7030005050 S.RES ERJ2GEJ 103 X (10 kΩ) 148/81.2 R431 7030005220 S.RES ERJ2GEJ 223 X (22 kΩ) 78.2/59.9 R323 7030008410 S.RES ERJ2GEJ 392 X (3.9 kΩ)
  • Page 30 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION 4030017420 S.CER ECJ0EC1H470J 73.4/8.7 C131 4030017720 S.CER ECJ0EB1H331K 24/28.3 4030017420 S.CER ECJ0EC1H470J 68.5/14.9 C132 4030018140 S.CER ECJ0EB1H391K 22.3/27.3 4030017420 S.CER ECJ0EC1H470J 70.3/14.9 C133 4030017460 S.CER ECJ0EB1E102K 20.6/28.3 4030017420 S.CER ECJ0EC1H470J 77.5/32.6 C134 4030017460 S.CER ECJ0EB1E102K...
  • Page 31 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION C198 4030016790 S.CER ECJ0EB1C103K 34.4/32.9 4030017550 S.CER ECJ0EC1H1R5B 24.7/59.3 C199 4030017460 S.CER ECJ0EB1E102K 32.5/37.7 C269 4030017610 S.CER ECJ0EC1H090C 23.6/56.7 C200 4030016790 S.CER ECJ0EB1C103K 31.7/50.4 4030017620 S.CER ECJ0EC1H100C 23.6/56.7 C201 4030017460 S.CER ECJ0EB1E102K 31.7/51.4 C270 4030017460 S.CER ECJ0EB1E102K...
  • Page 32 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION C337 4030016930 S.CER ECJ0EB1A104K C399 4510004630 S.ELE ECEV1CA100SR 114.1/75.8 [F2721D], [F2821D] only 96.7/29.2 C400 4030017460 S.CER ECJ0EB1E102K 110.1/72.2 C338 4030016930 S.CER ECJ0EB1A104K C401 4030006860 S.CER C1608 JB 1H 102K-T 8.9/87 [F2721D], [F2821D] only 111.7/11 C402...
  • Page 33 [MAIN UNIT] [MAIN UNIT] ORDER ORDER DESCRIPTION DESCRIPTION LOCATION LOCATION C503 4030017420 S.CER ECJ0EC1H470J 106.9/106.7 6510023210 CNR CD6125SA1J0 <CVI> C504 4030017420 S.CER ECJ0EC1H470J 112.6/106.7 6510021300 S.CNR 52365-1091 84.9/93.5 C505 4030017420 S.CER ECJ0EC1H470J 128.6/106.9 C508 4030017420 S.CER ECJ0EC1H470J 110.8/106.6 C509 4030017420 S.CER ECJ0EC1H470J 99.9/87.6 7120000470 JMP ERDS2T0...
  • Page 34 SECTION 7 MECHANICAL PARTS AND DISASSEMBLY [CHASSIS PARTS] [MAIN UNIT] REF. NO. ORDER NO. DESCRIPTION QTY. REF. NO. ORDER NO. DESCRIPTION QTY. 6510004880 Connector MR-DS-E 01 8900013680 Cable OPC-1414 <CMI>T 8010019801 2781 chassis-1 6510023210 CD6125SA1J0 8110008270 2781 cover Screw PH BT M3 × 8 NI-ZU Bead HF70BB9.5 ×...
  • Page 35 7 - 2...
  • Page 36 SECTION 8 SEMI-CONDUCTOR INFORMATION • • TRANSISTOR AND FET’S DIODES 2SA1577 T106 Q 2SB1132 Q 2SC3356 T1B R25 2SC4116 BL 2SC4215 O DAN202U T106 1SS375-TL 1SV307 DA204U DA221 TL (Symbol: HQ) (Symbol: BAQ) (Symbol: R25) (Symbol: LL) (Symbol: QO) (Symbol: FH) (Symbol: TX) (Symbol: K) (Symbol: K)
  • Page 37 SECTION 9 BOARD LAYOUTS The combination of this page and the next page shows the unit layout in the same configuration as the actual 9-1 FRONT-A UNIT (for IC-F2700 Series) P.C. Board. • TOP VIEW DIAL AF VOLUME H100 H105 H110 H115 to MIC JACK...
  • Page 38 FRONT-A UNIT • BOTTOM VIEW (for IC-F2700 series) The combination of this page and the previous page shows the unit layout in the same configuration as the actual P.C. Board. H115 H110 H105 H100 to MAIN UNIT 9 - 2...
  • Page 39 9-2 FRONT-B UNIT (for IC-F2800 Series) • TOP VIEW The combination of this page and the next page shows the unit layout in the same configuration as the actual P.C. Board. AF VOLUME H100 H105 H110 H115 H120 H125 H130 H135 H140 H145...
  • Page 40 FRONT-B UNIT • BOTTOM VIEW (for IC-F2800 series) The combination of this page and the previous page shows the unit layout in the same configuration as the actual P.C. Board. H165 H160 H155 H150 H145 H140 H135 H130 H125 H120 H115 H110 H105...
  • Page 41 The combination of this page and the next page shows the unit layout in the same configuration as the actual 9-3 MAIN UNIT P.C. Board. • TOP VIEW DC Cable to ANT EP11 EP10 V115 V110 IC29 Power amplifier V105 V100 to GPS Internal Speaker...
  • Page 42 The combination of this page and the previous page shows the unit layout in the same configuration as the MAIN UNIT EXT. 25PIN Connector actual P.C. Board. SPEAKER • BOTTOM VIEW V115 SP– V110 V105 V100 H160 H155 H150 H145 H140 H135 H130...
  • Page 43 SECTION 10 BLOCK DIAGRAM 10 - 1...
  • Page 44 SECTION 11 VOLTAGE DIAGRAM 11-1 FRONT-A UNIT (for IC-F2700 Series) 11 - 1...
  • Page 45 11-2 FRONT-B UNIT (for IC-F2800 Series) 11 - 2...
  • Page 46 INT. SP C467 C410 C386 IC21 VSS 3 C343 C340 0.47 Yellow TC7MET374AFK C372 C369 C465 C464 R365 R348 C439 R324 DTC363EK 0.001 0.001 R323 Black IC38 2.2k 3.9k C480 C479 LA4425A 0.001 (IC-F2721/D, IC-F2710 series only) 11 - 3...
  • Page 47 VCOV VC0V C257 IC29 C555 C549 7.0 V C242 C281 C284 C285 C533 C534 C347 C357 0.001 ACZ1005Y-102-T 470p 0.01 470p RA30H4452M-21 R127 [H-25W] R299 R147 R174 2.2k R193 R237 C548 R194 ACZ1005Y-102-T R209 RA30H4047M-21 6.8k 6.8k [L-25W] C153 R452 R451 TX 0.8 V TX 6.9 V...
  • Page 48 Phone : +34 (93) 590 26 70 Fax : +34 (93) 589 04 46 Glenwood Centre #150-6165 Highway 17 Delta, B.C., V4K 5B8, Canada : http://www.icomspain.com E-mail : icom@icomspain.com Phone : +1 (604) 952-4266 Fax : +1 (604) 952-0090 : http://www.icomcanada.com E-mail : info@icomcanada.com Unit 9, Sea St., Herne Bay, Kent, CT6 8LD, U.K.
  • Page 49 S-14127MZ-C1 1-1-32, Kamiminami, Hirano-ku, Osaka 547-0003, Japan © 2005 Icom Inc.

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