IC-91A_AD_serv.pdf

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1、SERVICE MANUAL VHF/UHF FM TRANSCEIVER S-14230HZ-C1 May. 2006 VHF/UHF DIGITAL TRANSCEIVER INTRODUCTION This service manual describes the latest service information for the IC-91A VHF/UHF FM TRANSCEIVER, IC-91AD VHF/UHF DIGITAL TRANSCEIVER at the time of publication. ORDERING PARTS Be sure to include

2、the following four points when ordering replacement parts: 1. 10-digit Icom parts number 2. Component name and informations 3. Equipment model name and unit name 4. Quantity required 5030002880 LCD HLM7972-010100 IC-91A Main unit 5 pieces 8810009560 Screw PH BT M26 ZK IC-91A Chassis 10 pieces Addres

3、ses are provided on the inside back cover for your convenience. REPAIR NOTES 1. Make sure the problem is internal before disassembling the transceiver. 2. DO NOT open the transceiver until the transceiver is disconnected from its power source. 3. DO NOT force any of the variable components. Turn the

4、m slowly and smoothly. 4. DO NOT short any circuits or electronic parts. An insulated turning tool MUST be used for all adjustments. 5. DO NOT keep power ON for a long time when the transceiver is defective. 6. DO NOT transmit power into a signal generator or a sweep generator. 7. ALWAYS connect a 3

5、0 dB to 40 dB attenuator between the transceiver and a deviation meter or spectrum analyzer when using such test equipment. 8. READ the instructions of test equipment thoroughly before connecting equipment to the transceiver. To upgrade quality, all electrical or mechanical parts and internal circui

6、ts are subject to change without notice or obligation. MODELVERSIONSYMBOL IC-91AD U.S.A.USA ExportEXP IC-91A U.S.A.USA-1 TaiwanTPE KoreaKOR AustraliaAUS Export EXP-1 EXP-2 Icom, Icom Inc. and logo are registered trademarks of Icom Incorporated (Japan) in the United States, the United Kingdom, German

7、y, France, Spain, Russia and/or other countries. NEVER connect the transceiver to an AC outlet or to a DC power supply 3.7 V. Such a connection could cause a fire or electric hazard. DO NOT expose the transceiver to rain, snow or any liquids. DO NOT reverse the polarities of the power supply when co

8、nnecting the transceiver. DO NOT apply an RF signal of more than 20 dBm (100 mW) to the antenna connector. This could damage the trans- ceivers front end. CAUTION TABLE OF CONTENTS SECTION 1 SPECIFICATIONS SECTION 2 INSIDE VIEWS SECTION 3 DISASSEMBLY INSTRUCTIONS SECTION 4 UT-121 UNINSTALLATION SECT

9、ION 5 CIRCUIT DESCRIPITON 5-1 RECEIVER CIRCUITS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5-2 TRANSMITTER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 5-3

10、PLL CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 5-4 OTHER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 5-5 POWER SUPPLY CIRCU

11、ITS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 5-6 PORT ALLOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 SECTION 6 ADJUSTMENT PROCEDURES 6-1 PREPARATION . . .

12、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 6-2 FREQUENCY AND TRANSMIT ADJUSTMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 SECTION 7 PARTS LIST SECTION 8 MECHANICAL PARTS AND DISASSEMBLY SE

13、CTION 9 SEMICONDUCTOR INFORMATION SECTION 10 BOARD LAYOUTS 10-1 LOGIC UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 10-2 MAIN UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14、 . . . . . . . . . . . . . . . . . . . . . . . . 10-1 10-3 RF UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 10-4 UT-121 (Optional product; CODEC UNIT for IC-91AD). . . . . . . . . . . . . . . . . . . . .

15、 . . . . . . . . . . 10-1 10-5 VCO UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 SECTION 11 BLOCK DIAGRAM SECTION 12 VOLTAGE DIAGRAMS 12-1 LOGIC UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1 12-2 MAIN UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2 12-3 RF UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3 12-4 VCO UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-4 12-5 UT-121 (Optional product; CODEC UNIT for IC-91AD). . . . . . . . . . . .

18、 . . . . . . . . . . . . . . . . . . . 12-5 1 - 1 SECTION 1 SPECIFICATIONS GENERAL Frequency coverange : Operating mode:FM, AM*, WFM*, DV (*RX only) Memory channels: 1304 channels (Incl. 100 scan edges and 4 call ch.) Frequency stability: 2.5 ppm (20C to +60C; 4F to 140F) Tuning steps: 5/6.25/8.33/9

19、/10/12.5/15/20/ 25/30/50/100/125 and 200 kHz Antenna impedance: 50 (SMA type) Power supply: 10.016.0 V DC for external DC power, or specifi ed Icoms battery pack Digital transmission speed : 4.8 kbps Voice coding speed: 2.4 kbps Current drain (at 7.4 V DC): TRANSMIT VHF High 2.1 A typ. Low 0.8 A (ap

20、prox.) UHF High 2.2 A typ. Low 0.8 A (approx.) RECEIVE Stand-by 170 mA typ. (dualwatch; FM/DV) Max. audio 340 mA typ. (dualwatch; FM/DV) Operating temp. range: 20C to +60C; 4F to 140F Dimensions (projections not included) :58.4 (W) 103 (H) 34.2 (D) mm 2 9/32 (W) 4 1/16 (H) 1 11/32 (D) in Weight (app

21、rox.):300 g; 10.6 oz (antenna, BP-217 included) TRANSMITTER Output power (at 7.4 V DC) : 5.0 W (High) 0.5 W (Low; aprrox.) Modulation systemFM : Variable reactance frequency modulation DVGMSK reactance frequency modulation Maximum deviation: 5.0 kHz (FM wide: approx.) 2.5 kHz (FM narrow: approx.) Sp

22、urious emissions: Less than 60 dB Ext. mic. connector: 3-conductor 2.5 (d) mm; (1/10)/2 k RECEIVER Receiving system: FM/AM/DVDouble-conversion superheterodyne system WFMTriple-conversion superheterodyne system Intermediate frequencies: 1st A band B band 61.65/59.25 MHz (WFM) 46.35 MHz 2nd 450 kHz/13

23、.35 MHz (WFM) 3rd1.95 MHz (WFM only) Sensitivity:(except spurious points) Selectivity: FM (Wide), AMMore than 50 dB FM (Narrow), DVMore than 45 dB WFMMore than 300 kHz/3 dB Less than 700 kHz/20 dB Spurious image rejection: VHFMore than 60 dB UHFMore than 50 dB (IF; More than 60 dB) Audio output powe

24、r (at 7.4 V DC) : More than 200 mW (at 10% distortion with an 8 load) Ext. speaker connector: 3-conductor 3.5 (d) mm; (1/8)/8 All stated specifi cations are subject to change without notice or obligation. Available for the IC-91AD or when UT-121 is installed into the IC-91A. ? ? ? ? ? ? ? ? ? ? ? ?

25、? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

26、? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - - - - - SECTION 2 INSIDE VIEWS 2 - 1 MAIN UNIT (TOP VIEW) MAIN UNIT (BOTTOM VIEW) UT-121 (Optional Product ; CODEC UNIT for IC-91AD) (TOP VIEW) UT-121 (Optional Product ; COD

27、EC UNIT for IC-91AD) (BOTTOM VIEW) LOGIC UNIT RF UNIT (TOP VIEW) RF UNIT (BOTTOM VIEW) DC switch Q1000: HAT1026 D1000: MA2S728 D1001: RB060 TX power amplifier (Q100: RD01MUS1) VCO UNIT APC amplifier (IC150: NJM3404) A_BAND 1st IF mixer (IC900: PC2757TB) 2nd IF filters (FI100, FI200: CFW450E) Mode sw

28、itch (IC700: CD4066) A_BAND PLL IC (IC400: MB15E03SLPFV1) A_BAND FM IF IC (IC100: TA31136FNG) B_BAND FM IF IC (IC200: TA31136FNG) A_BAND 2nd IF filter (FI2: SFECV13.35MAS) B_BAND 1st IF filter (FI50: FL-335) Clock oscillator for IC101 / IC350 (X100: CR-820) Clock oscillator for IC202 (X200: CR-821)

29、? GMSK modem IC (IC202: CMX589AD5) Linear codec IC (IC350: AD73311ARSZ) AMBE audio codec IC (IC101: AMBE-2020) ALC amplifier (IC300: AN6123MS) AF power amplifier (IC550: NJM2070M) Reset IC (IC100: R1150H022D) Reference frequency oscillator (X1: CR-774) RS-232C interface (IC52: MAX3221IPWR) CPU (IC1:

30、 HD64F2238RTF13V) D/A converter (IC303: M62364FP) SECTION 3 DISASSEMBLY INSTRUCTIONS 3 - 1 Removing the rear panel 1 Unscrew 2 screws A and remove the plate B. 2 Remove the CODEC unit (UT-121) if installed. (See the page 4-1 “2” for uninstallation) 3 Unscrew 2 screws C and 2 screws D. 4 Disconnect t

31、he flat cable E from MAIN unit J702. 5 Remove the rear panel. Removing the MAIN unit 1 Unscrew the screw A and 2 screws B. 2 Unsolder 6 points C. 3 Remove the MAIN unit from the rear panel in the direction of the arrow. D E B A C Rear panel CODEC unit (UT-121) J702 LOGIC unit A B B B B Front panel B

32、 A MAIN unit Rear panel C A A D D B B B RF unit Rear panel C Removing the LOGIC unit 1 Unsolder 2 points A. 2 Unscrew 6 screws B and remove the LOGIC unit from the front panel. Removing the RF unit 1 Unsolder 2 points A. 2 Unsolder 3 points B and remove the shield plate C. 3 Unscrew 4 screws D and r

33、emove the RF unit from the rear panel SECTION 4 UT-121 UNINSTALLATION 4 - 1 2 screws Unit cover UT-121 (Top view) Notches Tweezers q Turn the power OFF, and remove the battery pack. w Unscrew 2 screws to remove the unit cover. e Insert the tweezers into the notches of the UT-121, and remove it as sh

34、own below. r Screw 2 screws to assemble the unit cover. 2 screws Unit cover RECOMMENDATION: Critical technique is necessary for the UT-121 uninstallation, therefore, we recommend you to uninstall it at your dealer or service center. 5-1 RECEIVER CIRCUITS This transceiver has two receiving lines call

35、ed A_BAND and B_ BAND for dualwatch capability. A_BAND corresponds to FM/WFM/ AM mode receiving within 0.495999 MHz range, and B_BAND corresponds to FM/FM-N/AM/DV mode receiving within 118174 MHz and 350470 MHz ranges. 5-1-1 RF CIRCUITS (RF UNIT) This transceiver has six RF circuits to provide wide

36、receiving range. The received signals from the antenna connector (CHASSIS; J1) are applied to each RF circuit for the frequency coverage, and amplified within the frequency coverage. While receiving 0.49576 MHz The received signals of 76 MHz and below are passed through the low-pass filter (LPF; L20

37、0, L201, C201C204) via the two LPFs (L1L3, C1C6; L5L7, C10C14), attenuator (D10) and band switch (D200). The 0.49530 MHz band signals are passed through the band switch (D201), then applied to the RF amplifier (Q200) via the low-pass filter (L202, L203, C205C209). The 3076 MHz band signals are appli

38、ed to the tuned RF amplifier (Q250, D252, D255) via the band switch (D250). The amplified signals are applied to the A_BAND 1st mixer (IC900, pin 1) via the band switches (D203 or D256, D707). - 0.49576 MHz - While receiving 76118 MHz or 174260 MHz The 76118 MHz band signals are passed through the t

39、wo LPFs (L1L3, C1C6; L5L7, C10C14), attenuator (D10) and low-pass filter (L300, L301, C301C305) via the band switch (D300). The 174260 MHz band signals are passed through the LPF (L1 L3, C1C6), HPF (L4, C7C9), attenuator (D7) and high-pass filter (HPF; L302, L303, C306C310) via the band switch (D302

40、). The filtered signals are applied to the tuned RF amplifier (Q300, Q301, D305, D307, D308) via the band switch (D301/D303). The amplified signals are applied to the A_BAND 1st mixer (IC900, pin 1) via the band switches (D311, D707). SECTION 5 CIRCUIT DESCRIPTION 5 - 1 LPF LPF D255 Tuned RF amplifi

41、er D707 D256 D203 Q250 Q200 to the A_BAND 1st mixer (IC900, pin 1) 0.495-30 MHz D252 RF amp. ATT D201 0.495-76 MHz D250 D200 D10 2 LPFs from the antenna 30-76 MHz LPF LPF Tuned RF amplifier D307, D308 Q300D305Q301 D707 to the A_BAND 1st mixer (IC900, pin 1) D311 76-118 MHz LPF D301 D10 D300 LPFHPF 1

42、74-260 MHz HPFATT ATT D303 D7 D302 from the antenna - 76118 MHz or 174260 MHz - Tuned RF amplifier 2 LPFs D402, D403 Q401 D401 D509 to the A_BAND 1st mixer (IC900, pin 1) D405 Tuned RF amplifier D451, D452 Q450 D450 D400 to the B_BAND 1st mixer (MAIN UNIT; IC50, pin 1) D454 ATT D10 from the antenna

43、BPF Q400 118-174 MHz RF amp. LPF from the antenna Tuned RF amplifier 260-350 MHz, 470-600 MHz D505, D506 D7 HPF LPF ATT Q500 D502 Q501 D509 to the A_BAND 1st mixer (IC900, pin 1) D508 D500 While receiving 118174 MHz The 118174 MHz band signals are passed through the two LPFs (L1L3, C1C6; L5L7, C10C1

44、4) and attenuator (D10), then applied to the RF amplifier (Q400) via the band switch (D400) and bandpass filter (BPF; L400, L405, C400, C401). The amplified signals are applied to the tuned RF amplifiers for A_ BAND (Q401, D401D403) and B_BAND (Q450, D450D452). The amplified signals by Q401 are then

45、 applied to the A_BAND 1st mixer (IC900, pin 1) via the band switches (D405, D509). The amplified signals by Q450 are then applied to the B_BAND 1st mixer (MAIN UNIT; IC50, pin 1) via the band switch (D454) and J1001 (pin 15). - 118174 MHz - While receiving 260350 MHz or 470600 MHz The 260350 MHz an

46、d 470600 MHz band signals passed through the LPF (L1L3, C1C6) and HPF (L4, C7C9), then applied to the tuned RF amplifier (Q500, Q501, D502, D505, D506) via the attenuator (D7) and band switch (D500). The amplified signals are applied to the A_BAND 1st mixer (IC900, pin 1) via the band switches (D508, D509). - 260350 MHz or 470600 MHz - 5 - 2 While receiving 350470 MHz The 350470 MHz ba