IC-706MK2G_serv_1999.pdf

《IC-706MK2G_serv_1999.pdf》由会员分享，可在线阅读，更多相关《IC-706MK2G_serv_1999.pdf（85页珍藏版）》请在收音机爱好者资料库上搜索。

1、SERVICE MANUAL HF/VHF/UHF ALL MODE TRANSCEIVER i706MKG IC-706MK2G 99.3.11 7:31 PM Page 1 INTRODUCTION This service manual describes the latest service information for the IC-706MKIIG HF/VHF/UHF ALL MODE TRANS- CEIVER at the time of publication. To upgrade quality, any electrical or mechanical parts

2、and internal circuits are subject to change without notice or obligation. DANGER NEVER connect the transceiver to an AC outlet or to a DC power supply that uses more than 16 V. This will ruin the transceiver. DO NOT expose the transceiver to rain, snow or any liquids. DO NOT reverse the polarities o

3、f the power supply when con- necting 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. ORDERING PARTS Be sure to include the following four points when ordering replacement parts: 1. 10-digit order numbers

4、 2. Component part number and name 3. Equipment model name and unit name 4. Quantity required 1110004080 S.ICPC2709TIC-706MKIIG MAIN UNIT 05 pieces 8810009020 Screw FH M2.6 x 5 ZK IC-706MKIIG Top cover10 pieces Addresses are provided on the inside back cover for your convenience. REPAIR NOTES 1. Mak

5、e sure a 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 them slowly and smoothly. 4. DO NOT short any circuits or electronic parts. An insu- late

6、d tuning tool MUST be used for all adjustments. 5. DO NOT keep power ON for a long time when the trans- ceiver is defective. 6. DO NOT transmit power into a 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

7、ana- lyzer when using such test equipment. 8. READ the instructions of test equipment thoroughly before connecting equipment to the transceiver. VERSION NO. #02, #12 #03, #13 #04, #14 #05, #15 #08, #18 VERSION Europe France Spain U.S.A. Other SYMBOL EUR FRA ESP USA OTH TABLE OF CONTENTS SECTION 1SPE

8、CIFICATIONS SECTION 2INSIDE VIEWS SECTION 3CIRCUIT DESCRIPTION 3 - 1 RECEIVER CIRCUITS. 3 - 1 3 - 2 TRANSMITTER CIRCUITS. 3 - 4 3 - 3 PLL CIRCUITS. 3 - 6 3 - 4 LOGIC CIRCUITS. 3 - 8 SECTION 4ADJUSTMENT PROCEDURES 4 - 1 PREPARATION BEFORE SERVICING . 4 - 1 4 - 2 PLL ADJUSTMENTS. 4 - 2 4 - 3 TRANSMITT

9、ER ADJUSTMENTS . 4 - 2 4 - 4 RECEIVER ADJUSTMENTS. 4 - 8 4 - 5 SET MODE ADJUSTMENT. 4 - 10 SECTION 5PARTS LIST SECTION 6MECHANICAL PARTS AND DISASSEMBLY SECTION 7SEMI-CONDUCTOR INFORMATION SECTION 8BOARD LAYOUTS 8 - 1 DISPLAY BOARD. 8 - 1 8 - 2 MAIN BOARD. 8 - 3 8 - 3 HPF AND DRIVER BOARD. 8 - 5 8 -

10、 4 PA UNIT. 8 - 7 8 - 5 PLL UNIT. 8 - 9 8 - 6 FILTER BOARD. 8 - 11 SECTION 9BLOCK DIAGRAM SECTION 10VOLTAGE DIAGRAM I GENERAL Frequency coverage: Receive0.030 200.000 MHz* 430.000 470.000 MHz* Transmit1.800 1.999 MHz* 3.500 3.999 MHz* 7.000 7.300 MHz* 10.100 10.150 MHz 14.000 14.350 MHz 18.068 18.16

11、8 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 only) Number of memory ch.: 107 (99 regular, 6 scan edges,1 call) Antenna connector: SO-23

12、9 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 than 1 ppm/hr. at +25C (+77F). Temperature fluctuations 0C to +50C (+32F to +122F) less tha

13、n 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) 2932(H) 778(D) inch Weight: 2.45 kg (5 lb 6 oz) CI-V connector: 2-conductor 3.5 (d) mm

14、(1/8)/8 ACC connector: 13-pin I 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 modulation AMLow level modulation FMVariable reactance modulation Spurious emissions:

15、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-conductor 6.35 (d) mm (1/4) RTTY connector: 3-conductor 3.5 (d) mm (1/8) I RECEIVER Re

16、ceive 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 at 12 dB SINAD. *Except 44.5 MHz, 89 MHz. Squelch Sensitivity : (pre-amp ON) SSBL

17、ess 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 an optional filter unit and with mid bandwidth selected. Spurious and image rejecti

18、on 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-conductor 3.5 (d) mm (1/8)/8 EXT SP connector: 2-conductor 3.5 (d) mm (1/8)/8 3rd IF 4

19、55 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 1 - 1 SECTION 1SPECIFICATIONS FM 0.5 V 0.25 V 0.18 V 0.18 V FREQUENCY 0.5 1.8 MHz 1.8 28 MHz* 28 29.999 MHz 50 MHz b

20、and 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. Predrive amplifier (Q101: 2SK2854) HPF board D/A converter (IC2201: M62352GP) ?PA AND PLL UNITS FILTER board MAIN CPU

21、 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 * (IC1011: LC7153M-TLM) Balanced modulator * (IC1041: NJM1496V) Discriminator (X791: CD

22、B455CX24) 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-100, FL-101, FL-103 FL-233, FL-232 Power amplifers (Q171, Q172, Q231: SRFJ7044)

23、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) AF power amplifer (IC231: LA4425A) PLL unit AF volume controller (IC201: M5282FP

24、) VCO3 * (Q361: 2SK508) Reference oscillator (X621: CR-275A 30.00000 MHz) *Located under side of the point ?MAIN AND FILTER BOARDS 2 - 1 SECTION 2INSIDE VIEWS 3-1 RECEIVER CIRCUITS 3-1-1 HF/50 MHz RF CIRCUIT (FILTER, MAIN AND HPF BOARDS) HF/50 MHz RF filters pass only the desired band signals and su

25、ppress 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 filters as below, the transmit/ receive switching relay (FILTER board; RL1) and low-pass fil

26、ter (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 through the high-pass filter (L132, L133, C132C137) to suppress strong signals below 1.

27、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 MAIN board. (2) 230 MHz The signals from the low-pass filter (L101, L102, C101C105) ar

28、e 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 the high-pass filter (L174, L175, C177C181) via D171 and are then applied to the preampli

29、- 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 have a preamplifier and band- pass filters respectively. VHF RF CIRCUIT The VHF RF sign

30、als 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 at the preamplifier circuit (Q403). The ampli- fied signals are then applied to the an

31、other 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 switching circuit (D341, D342, D343). The signals are amplified at the preamplifier circuit

32、(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, D407, D410, D454, D453, D454 and D456 are varactor diodes that tune the ceinter frequen-

33、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 “2MBL” from PLL unit, then the varactor diodes (D408, D407) are disconnect- ed. Used RF hi

34、gh-pass filter (HPF board) Used RF low-pass filter (FILTER board) 3 - 1 SECTION 3CIRCUIT DESCRIPTION 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 demod. circuit (IC791) ANT1 0.0360 MHz LPF ANT2 6047

35、0 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 Optional filter-2 amp. Pre-amp. IC151 Frequency (MHz

36、) 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 (MHz) 1522 MHz 2230 MHz 3040 MHz 4060 MHz Control signa

37、l L5H L6H THH B7H Control signal THH L2H L3H L4H Entrance coil D111 D121 D131 D141 Entrance coil D151 D161 D111 D171 3-1-3 PREAMPLIFIER CIRCUIT (MAIN BOARD) The preamplifier circuit in the IC-706MKIIG has approx. 15dB gain over a wide-band frequency range. When the preamplifier is turned ON, the sig

38、nals 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 the 1st LO signal to convert the receive signal frequencies

39、 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) enter the MAIN board from the PLL unit via J281. The LO s

40、ignal 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 (FI511) to sup- press out-of-band signals. The 69 MHz 1st

41、 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 voltage is supplied to the transmit/receive switch- ing circui

42、t (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 mixer circuit mixes the 1st IF signals and 2nd LO signal (60

43、.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 (FI561) to suppress undesired signals, such as the 2nd LO signal, and are then applied to the noise blanker gate (D561, D562). Wh