IC-706MK2G_serv_2007.pdf

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1、S-14411XZ-C1 June. 2007 HF/VHF/UHF ALL MODE TRANSCEVER This service manual describes the latest service information for the IC-706MKIIG HF/VHF/UHF ALL MODE TRANSCEVER at the time of publication. NEVER connect the transceiver to an AC outlet or to a DC power supply that uses more than 13.8 V. This wi

2、ll ruin the transceiver. DO NOT expose the transceiver to rain, snow or any liquids. DO NOT reverse the polarities of the power supply when connecting the transceiver. DO NOT apply an RF signal of more than 20 dBm (100 mW) to the antenna connector. This could damage the transceivers front-end. To up

3、grade quality, any electrical or mechanical parts and internal circuits are subject to change without notice or obligation. MODELVERSIONUT-106 IC-706MKIIG USA Available as an option EUR FRA ESP OTH ITA ITR CHN USA-1 Built-in EUR-1 FRA-1 ESP-1 OTH-1 ITA-1 ITR-1 CHN-1 Be sure to include the following

4、four points when ordering replacement parts: 1. 10-digit Icom parts numbers 2. Component name 3. Equipment model name and unit name 4. Quantity required 1110003491 S.IC TA31136FNG IC-706MKIIG MAIN UNIT 5 pieces 8820001210 Screw 2438 screw IC-706MKIIG Top cover 10 pieces Addresses are provided on the

5、 inside back cover for your convenience. 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. ORDERING PARTS 1. Make sure the problem is internal before disassembling the trans

6、ceiver. 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 them slowly and smoothly. 4. DO NOT short any circuits or electronic parts. An insulated tuning tool MUST be used for all adjustments. 5. DO NOT ke

7、ep power ON for a long time when the transceiver is defective. 6. DO NOT transmit power into a Standard Signal Generator or a Sweep Generator. 7. ALWAYS connect a 50 dB to 60 dB attenuator between the transceiver and a Deviation Meter or Spectrum Analyzer when using such test equipment. 8. READ the

8、instructions of test equipment throughly before connecting a test equipment to the transceiver. REPAIR NOTES INTRODUCTIONCAUTION CONTENTS SECTION 1 SPECIFICATIONS SECTION 2 INSIDE VIEWS SECTION 3 CIRCUIT DESCRIPITON 3-1 RECEIVER CIRCUITS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9、 . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3-2 TRANSMITTER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 3-3 PLL CIRCUITS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10、. . . . . . . . . . . . . 3-6 3-4 LOGIC CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8 SECTION 4 ADJUSTMENT PROCEDURES 4-1 PREPARATION BEFORE SERVICING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11、. . . . . . . . . . . 4-1 4-2 PLL ADJUSTMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 4-3 TRANSMITTER ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 4-4 RECEIVE

12、R ADJUSTMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8 4-4 SET MODE ADJUSTMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10 SECTION 5 PARTS LIST SECTION 6 MECHANICAL PARTS AND

13、 DISASSEMBLY SECTION 7 SEMI-CONDUCTOR INFORMATION SECTION 8 BOARD LAYOUTS SECTION 9 BLOCK DIAGRAM SECTION 10 VOLTAGE DIAGRAM DISPALY AND VR BOARDS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 MAIN UNIT AND HPF BOARDS. . . . . . . . . . . . .

14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2 PLL UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8 FILTER BOARD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15、 . . . . . . . . . . . . . . . . . . . . . . . 10-10 PA UNIT AND DRIVER BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11 1 - 1 SECTION 1 SPECIFICATIONS GENERAL Frequency coverage: Receive0.030 200.000 MHz* 430.000 470.000 MHz* Transmit1.800 1.99

16、9 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 21.450 MHz 24.890 24.990 MHz 28.000 29.700 MHz 50.000 54.000 MHz* 144.000 148.000 MHz* 430.000 450.000 MHz* *Depending on version. Mode : USB, LSB, CW, RTTY (FSK), AM, FM, WFM (WFM is for receiver o

17、nly) Number of memory ch.: 107 (99 regular, 6 scan edges,1 call) Antenna connector: SO-239 2 (for HF/50 MHz and 144/440 MHz)/50 Power supply requirement : 13.8 V DC 15% (negative ground) Frequency stability: Less than 7 ppm from 1 min. to 60 min. after power ON. After that, rate of stability less th

18、an 1 ppm/hr. at +25C (+77F). Temperature fluctuations 0C to +50C (+32F to +122F) less than 5 ppm. Current consumption: Transmitmax. power20 A Receivestandby1.8 A max. audio2.0 A Usable temperature range : 10C to +60C (+14F to +140F) Dimensions: 167(W) 58(H)200(D) mm (projections not included)6916(W)

19、2932(H)778(D) inch Weight: 2.45 kg (5 lb 6 oz) CI-V connector: 2-conductor 3.5 (d) mm (1/8)/8 ACC connector: 13-pin TRANSMITTER Output power: 1.850 MHz bandSSB/CW/RTTY/FM 5100 W AM240 W 144 MHz bandSSB/CW/RTTY/FM 550 W AM220 W 440 MHz bandSSB/CW/RTTY/FM 220 W AM28 W Modulation system: SSBBalanced mo

20、dulation AMLow level modulation FMVariable reactance modulation Spurious emissions: Below 47.5 MHzLess than 50 dB (typical) Above 47.5 MHzLess than 60 dB Carrier suppression: More than 40 dB Unwanted sideband supp. : More than 50 dB Microphone connector: 8-pin modular jack (600 ) KEY connector: 3-co

21、nductor 6.35 (d) mm (1/4) RTTY connector: 3-conductor 3.5 (d) mm (1/8) RECEIVER Receive system: SSB/CW/AM/WFMDouble superheterodyne FMTriple superheterodyne Intermediate frequencies: *FM or FM-N mode only Receive sensitivity :(pre-amp ON) Note: SSB, CW and AM modes are measured at 10 dB S/N; FM mode

22、 at 12 dB SINAD. *Except 44.5 MHz, 89 MHz. Squelch Sensitivity : (pre-amp ON) SSBLess than 5.6 V FMLess than 0.32 V Selectivity*: SSB, CW, RTTYMore than 2.4 kHz/6 dB Less than 4.8 kHz/60 dB AM/FM-NMore than 8.0 kHz/6 dB Less than 30 kHz/40 dB FMMore than 12 kHz/6 dB Less than 30 kHz/60 dB *Without a

23、n optional filter unit and with mid bandwidth selected. Spurious and image rejection ratio: HF band70dB 50 MHz band65 dB (except IF through) 144/440 MHz band65 dB Audio output power : More than 2.0 W at 10% distortion (at 13.8 V DC)with an 8 load RIT variable range: 9.99 kHz PHONES connector: 3-cond

24、uctor 3.5 (d) mm (1/8)/8 EXT SP connector: 2-conductor 3.5 (d) mm (1/8)/8 3rd IF 455 kHz* 455 kHz* MODE SSB/AM-N/FM AM/FM-N CW RTTY WFM 1st IF 69.0115 MHz 69.0100 MHz 69.0106 MHz 69.0105 MHz 70.7000 MHz 2nd IF 9.0115 MHz 9.0100 MHz 9.0106 MHz 9.0105 MHz 10.7000 MHz FM 0.5 V 0.25 V 0.18 V 0.18 V FREQ

25、UENCY 0.5 1.8 MHz 1.8 28 MHz* 28 29.999 MHz 50 MHz band 144 MHz band 440 MHz band SSB/CW/RTTY 0.16 V 0.16 V 0.13 V 0.11 V 0.11 V AM 13 V 2 V 2 V 1 V 1 V 1 V All stated specifications are subject to change without notice or obligation. 2 - 1 SECTION 2 INSIDE VIEWS Predrive amplifier (Q101: 2SK2854) H

26、PF board D/A converter (IC2201: M62352GP) PA AND PLL UNITS FILTER board MAIN CPU clock (X2161: CR-636) MAIN CPU * (IC 2001: HD6433337YA56F) MAIN board 3rd IF filter for FM * (FI791: SFPC455E-TC01) MIC amplifier (IC931: PC5023GS-077-E1) AF selector switch * (IC861: BU4052BCFV-E2) Tx FM PLL IC * (IC10

27、11: LC7153M-TLM) Balanced modulator * (IC1041: NJM1496V) Discriminator (X791: CDB455CX24) FM IF IC * (IC791: TA31136FN) RX preamplifier (IC151: PC1658G) 1st mixer (D271: HSB88WSTR) 1st IF filter (FI511: FI-261) 2nd mixer * (D551: HSB88WSTR) 2nd IF filter (FI561: FL-23) Space for optional filters FL-

28、100, FL-101, FL-103 FL-233, FL-232 Power amplifers (Q171, Q172, Q231: SRFJ7044) DDS IC (IC101: SC-1246) BFO DDS IC (IC901: SC-1287) PLL IC * (IC461: LMX2306TMX) VCO1 * (Q301: 2SK508) VCO2 * (Q331: 2SK508) PA unit DRIVER board Drive amplifers (Q161, Q211: MRF1508TI) Predrive amplifer (Q121: MXR9745)

29、AF power amplifer (IC231: LA4425A) PLL unit AF volume controller (IC201: M5282FP) VCO3 * (Q361: 2SK508) Reference oscillator (X621: CR-275A 30.00000 MHz) *Located under side of the point MAIN AND FILTER BOARDS 3 - 1 SECTION 3 CIRCUIT DESCRIPTION 3-1 RECEIVER CIRCUITS 3-1-1 HF/50 MHz RF CIRCUIT (FILT

30、ER, MAIN AND HPF BOARDS) 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 8 high-pass filters for specified band use. HF/50 MHz RF signals from the ANT1 connector, pass through one of 7 low-pass filte

31、rs as below, the transmit/ receive switching relay (FILTER board; RL1) and low-pass filter (FILTER board; L1, L2, C1C5), and are then applied to the MAIN board via J1 (FILTER board). The signals from the FILTER board are applied to or bypass the 20 dB attenuator (R122, R125, R126). The signals pass

32、through the high-pass filter (L132, L133, C132C137) to suppress strong signals below 1.6 MHz and are then applied to the HPF board via the “SAF” terminal. (1) 0.032 MHz and 3040 MHz The signals pass through a low-pass filter (L101, L102, C101C105), and then applied to the preamplifier circuit on the

33、 MAIN board. (2) 230 MHz The signals from the low-pass filter (L101, L102, C101C105) are applied to one of 6 high-pass filters as at right above and are then applied to the preamplifier circuit on the MAIN board. (3) 4060 MHz The signals pass through the low-pass filter (L172, L173, C172C176) and th

34、e high-pass filter (L174, L175, C177C181) via D171 and are then applied to the preampli- fier circuit on the MAIN board. 3-1-2 VHF AND UHF RF CIRCUITS (PA UNIT) The VHF and UHF RF circuits pass and amplify only the desired band signals and suppresses any undesired band signals. The both RF circuits

35、have a preamplifier and band- pass filters respectively. VHF RF CIRCUIT The VHF RF signals from the ANT2 connector pass through the low-pass filter (L263L265, C274C276) and antenna switching circuit (D291D293). The signals are applied to the bandpass filter (D403, D409, D408), and are then amplified

36、 at the preamplifier circuit (Q403). The ampli- fied signals are then applied to the another bandpass filter (D407, D406, D410). UHF RF CIRCUIT The UHF RF signals from the ANT2 connector pass through the high-pass filter (L316, L317, C326C327), low- pass filter (L313L315, C322C324) and antenna switc

37、hing circuit (D341, D342, D343). The signals are amplified at the preamplifier circuit (Q453) between the 2 bandpass filters (D454, D453 and D454, D456). The filtered signals are applied to the MAIN board via J481 (PA unit) and are then applied to the preamplifier circuit. D403, D408, D409, D406, D4

38、07, D410, D454, D453, D454 and D456 are varactor diodes that tune the ceinter frequen- cy of an RF passband for wide bandwidth receiving and good image response rejection. On the VHF band, receiving signals are above 129 MHz, the switching diodes (D404, D405) are turned off by the control signal “2M

39、BL” from PLL unit, then the varactor diodes (D408, D407) are disconnect- ed. Used RF high-pass filter (HPF board) Used RF low-pass filter (FILTER board) RECEIVER CONSTRUCTION 1st LO: 69.0415 MHz 530.0115 MHz BPF LPFHPF 1st mixer D271 2nd LO: 60.0 MHz 2nd mixer D511 to AM demod. circuit (D761) to FM

40、demod. circuit (IC791) ANT1 0.0360 MHz LPF ANT2 60470 MHz Crystal filter FI511 69.0115 MHz Crystal filter NB gate FI561 to WFM detector circuit (IC631) to BFO circuit (IC1041) 9.0115MHz NB circuit FILTER BOARD PA UNIT HPF BOARD MAIN BOARD SSB, CW filter FI671 AM, FM-N filter FI681 Optional filter-1

41、Optional filter-2 amp. Pre-amp. IC151 Frequency (MHz) 0.032 MHz 24 MHz 48 MHz 815 MHz Frequency (MHz) 1522 MHz 2230 MHz 3060 MHz Control signal L5 L6 L7 Control signal L1 L2 L3 L4 Entrance coil RL15 RL13 RL5 RL9 Entrance coil RL11 RL7 RL3 Frequency (MHz) 0.032 MHz 24 MHz 48 MHz 815 MHz Frequency (MH

42、z) 1522 MHz 2230 MHz 3040 MHz 4060 MHz Control signal L5H L6H THH B7H Control signal THH L2H L3H L4H Entrance coil D111 D121 D131 D141 Entrance coil D151 D161 D111 D171 3 - 2 3-1-3 PREAMPLIFIER CIRCUIT (MAIN BOARD) The preamplifier circuit in the IC-706MKIIG has approx. 15dB gain over a wide-band fr

43、equency range. When the preamplifier is turned ON, the signals from the RF circuit are applied to the preamplifier (IC151) via D2182. Amplified or bypassed signals are applied to the 1st mixer circuit (D271). 3-1-4 1ST MIXER CIRCUIT (MAIN BOARD) The 1st mixer circuit mixes the receive signals with t

44、he 1st LO signal to convert the receive signal frequencies to a 69 or 70.7 MHz 1st IF signal. The signals from the preamplifier circuit, or signals which bypass the preamplifier, are passed through a low-pass fil- ter and then applied to the 1st mixer (D271). The 1st LO signals (69.0415539.0115 MHz)

45、 enter the MAIN board from the PLL unit via J281. The LO signal is amplified at IC281, filtered by a low- pass filter, and then, applied to the 1st mixer. 3-1-5 1ST IF CIRCUIT (MAIN BOARD) The 1st IF circuit filters and amplifies the 1st IF signals. The 1st IF signals are applied to a Crystal Filter

46、 (FI511) to sup- press out-of-band signals. The 69 MHz 1st IF signals (except WFM) pass through the crystal filter (FI511), however, the 70.7 MHz 1st IF signal (WFM) passes through a bandpass filter (L501L505, C501C506). Then the filtered signals are applied to the IF amplifier (IC521). The AGC volt

47、age is supplied to the transmit/receive switch- ing circuit (D521, D522) and D521/D522 function as PIN attenuators for AGC operation. The amplified signals are then applied to the 2nd mixer cir- cuit (D551) via the bandpass filter (L542L546, C542C545). 3-1-6 2ND MIXER CIRCUIT (MAIN BOARD) The 2nd mi

48、xer circuit mixes the 1st IF signals and 2nd LO signal (60.00 MHz) to convert the 1st IF to a 2nd IF. The 1st IF signals from the band pass filter (L542L546, C542C545) are converted to 9 MHz or 10.7 MHz 2nd IF signals at the 2nd mixer (D551). The 2nd IF signals are applied to the bandpass fil- ter (

49、FI561) to suppress undesired signals, such as the 2nd LO signal, and are then applied to the noise blanker gate (D561, D562). While in WFM mode, the IF signals pass through the low- pass filter (L601, C601C603), IF amplifiers (Q601, Q611), ceramic filter (FI611). The signals are then applied to the WFM demodulator circuit (IC631). 3-1-7 NOISE BLANKER CIRCUIT (MAIN BOARD) The noise blanker circuit detects pulse type noise, and turns OFF the signal line when noise appears