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www.r6-ru4montesecchieta.it IZ5CCV SERVICE MANUAL HF/VHF/UHF ALL MODE TRANSCEIVER i706MK™G...
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1110004080 S.IC µPC2709T IC-706MKIIG MAIN UNIT 05 pieces ceiver is defective. 8810009020 Screw FH M2.6 x 5 ZK IC-706MKIIG Top cover 10 pieces 6. DO NOT transmit power into a signal generator or a sweep generator. Addresses are provided on the inside back cover for your 7.
SECTION 3 CIRCUIT DESCRIPTION • Used RF high-pass filter (HPF board) 3-1 RECEIVER CIRCUITS Frequency Control Entrance Frequency Control Entrance 3-1-1 HF/50 MHz RF CIRCUIT signal coil (MHz) signal coil (MHz) (FILTER, MAIN AND HPF BOARDS) 0.03–2 MHz D111 15–22 MHz D151 HF/50 MHz RF filters pass only the desired band signals 2–4 MHz...
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While in WFM mode, the IF signals pass through the low- pass filter (L601, C601–C603), IF amplifiers (Q601, Q611), The preamplifier circuit in the IC-706MKIIG has approx. ceramic filter (FI611). The signals are then applied to the 15dB gain over a wide-band frequency range.
The S-meter signal from the main CPU (IC2001) is applied to the sub CPU and is then displayed on the S-meter read- In the IC-706MKIIG, the 1st LO frequency is shifted to out. change the 2nd IF because a fixed 2nd LO frequency (60 MHz) is used.
3-1-14 AF SELECTOR SWITCH (MAIN BOARD) Audio signals from the front or rear panel [MIC] connector enter the microphone amplifier IC (IC931, pin 22) and are The AF signals from one of the detector circuits are applied then amplified at the microphone amplifier or speech com- to the AF selector switch (IC861).
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3-2-4 FM MODULATION CIRCUIT (MAIN BOARD) The 144 MHz RF signals from the 1st mixer (D271) via the The microphone signals from Q961 are applied to the limiter low-pass filter (L251–253, C253–259) bypass the filters and amplifier (IC981a) and the splatter filter (IC981b). The 1750 pass through the bandpass filter (L182–L184, L195, L196, Hz European tone signal from the main CPU (IC2001 pin C181–C186, C195–C197) in the MAIN board.
The “FOR”, “VFOR” and “UFOR” voltages are combined to (3) SWR meter the “FORL” voltage and then applied to IC1091b (pin 6). The The “FORL” and “REFL” voltages are applied to the main “POCV” voltage from the D/A converter (IC2201, pin 3), CPU (IC2001, pins 32 and 36) via the analog switch determined by the RF power setting, is applied to IC1091b (IC2101, pins 11, 13 and 4, 3) respectively.
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3-3-3 2ND LO AND REFERENCE OSCILLATOR 3-3-4 BFO CIRCUIT CIRCUITS The DDS IC (IC901) generates a 10-bit digital signal. The signal is converted into an analog wave signal at the D/A The reference oscillator (X621, Q621) generates a 30.0 converter (R951–R970). The analog wave is passed MHz frequency used for the 1st LO and BFO circuits as a through the high-pass filter and low-pass filter.
3-4-2 SUB CPU PORT ALLOCATIONS • BFO frequency (DISPLAY board; IC1) RX BFO/3rd LO TX BFO/FM PLL ref. Mode frequency [MHz] frequency [MHz] Port Description number name 9.0130 9.0130 SFTL Input port for the [SHIFT] control. 9.0100 9.0100 Outputs a PTT signal. PTTS 9.0106 9.0106...
3-4-4 MAIN CPU PORT ALLOCATIONS (MAIN unit; IC2001) (MAIN unit; IC2001)–Continued Port Port Description Description number name number name Input port for the external paddle Outputs 1750 Hz European tone sig- ETON DASK (DASH). nal. Low : During key down Outputs a strobe signal for the option- MSST Input port for the external paddle...
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SECTION 4 ADJUSTMENT PROCEDURES 4-1 PREPARATION BEFORE SARVICING REQUIRED TEST EQUIPMENT EQUIPMENT GREDE AND RANGE EQUIPMENT GREDE AND RENGE Output voltage : 13.8 V DC Frequency range : 1 kHz ±10 % DC power supply Distortion meter Current capacity : 30 A or more Measuring range : 1–100 % Measuring range...
4-2 PLL ADJUSTMENTS ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST • Display frequency: Any Connect an RF volt- Maximum level L681, REFERENCE FREQUENCY • L623 (PLL unit) : Center meter to check point (0 dB or more) L682 •...
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• PLL AND PA UNITS L601 Reference frequency L623 Reference loop lock CP131 adjustment voltage check point R602 Reference loop lock L682 2nd LO level voltage adjustment adjustment L681 Main loop lock CP401 Reference frequency P681 voltage check point check point C306 Main loop lock C335...
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TRANSMITTER ADJUSTMENTS (continued) ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST • Display frequency: 29.10000 MHz MAIN Connect digital 1.8 V MAIN C1022 FM VCO • Mode : FM multimeter to check • [Q1 RF POWER] : H point CP1011.
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• MAIN UNIT CW carrier level CP921 check point CP1011 FM VCO check point C1022 FM VCO adjustment CP1041 AM modulation check point CW carrier level R921 adjustment AM modulation J281 FM deviation R1002 pre-setting adjustment L511 R999 L512 AM modulation R1042 adjustment Residual AM...
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TRANSMITTER ADJUSTMENTS (continued) ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST IDLING • Display frequency: 14.10000 MHz Connect 0.5 A increase from that R162 CURRENT • Mode : USB ammeter between R162 is in maximum • [Q2 MIC GAIN] : 1 (minimum) the DC power supply counterclockwise posi-...
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• PA UNIT R214 Drive idling adjustment R162 R174 Final idling Idling current J571 R231 adjustment pre-setting R175 • MAIN AND FILTER UNITS SWR detection adjustment SWR detection check point CP1071 SWR detection pre-setting 4 - 7...
4-4 RECEIVER ADJUSTMENTS ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST RECEIVER • Display freq. : 14.10000 MHz Rear Connect an AC milli- Muximum AF output MAIN L731, TOTAL GAIN • Mode : USB Panel voltmeter to the [EXT level L741 SP] jack with an 8 Ω...
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• MAIN UNIT Noise blanler CP632 check point L633 Noise blanler adjustment L621 R741 Receiver total gain L741 WFM receiving L632 adjustment adjustment CP631 WFM receiving L731 check point 4 - 9...
4-5 SET MODE ADJUSTMENT ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION • Enter adjustment set mode: Push [F-3 (TX)] to enter the TX ENTERING adjustment setting mode. ADJUSTMENT 1 Turn power OFF. SET MODE 2 Terminate the [REMOTE] jack with a Then advance to the following set- 3.5(d) mm mini-plug.
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SET MODE ADJUSTMENT (continued) ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION • Enter adjustment set mode: Push [F-2 (RX)] to enter the RX ENTERING ADJUSTMENT 1 Turn power OFF. adjustment setting mode. SET MODE 2 Terminate the [REMOTE] jack with a Then advance to the following set- 3.5(d) mm mini-plug.
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SECTION 7 SEMI-CONDUCTOR INFORMATION • TRANSISTOR AND FET’S • DIODES 2SA1576 R 2SA1577 Q 2SB1123T 2SB1132R 2SB1143 S 1SS302 1SS355 1SS375 1SS385 1SV237 (Symbol: FR) (Symbol: FR) (Symbol: BF) (Symbol: BA) (Symbol: C3) (Symbol: A) (Symbol: FH) (Symbol: 09) (Symbol: BB) 2SC4081 R 2SC4116 GR 2SC4213 B...
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SECTION 8 BOARD LAYOUT 8-1 DISPLAY BOARD • DISPLAY BOARD (TOP VIEW) LRXD LTXD (FRONT) MICE • VR BOARD TO FRONT UNIT W2 RF/SQL PHONES TO VR SPEAKER BOARD J1 TO DISPLAY BOARD SHIFT M-CH 8 - 1...
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• DISPLAY BOARD (BOTTOM VIEW) MODE POWER P.AMP/ATT TUNER/CALL RIT/SUB DISP LOCK MENU PHONES 8 - 2...
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8-2 MAIN BOARD • MAIN BOARD (TOP VIEW) J401 J461 TO PA UNIT J661 TO FILTER UNIT J2061 MSST J431 SPBK TO FILTER UNIT SPCH TO OPTIONAL UNIT UT-102 J1381 DRES PDST CON2 CON1 CON0 PBST MLLV AFGC TO PLL UNIT DSPS J254 AFBP...
8-6 HPF AND DRIVER BOARDS • HPF BOARD (TOP VIEW) TO MAIN UNIT J1 J101 • DRIVER BOARD (TOP VIEW) TO PA UNIT TO PA UNIT J210 J160 J200 J100 J201 J101 TO PA UNIT TO PA UNIT J211 J161 8 - 5...
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8-4 PA UNIT • PA UNIT (TOP VIEW) J661 TO MAIN J401 J612 J611 ETKY ETKY J621 ETST ETST ET14 ET14 TO PLL J252 TO MAIN UNIT J141 P481 P101 TO MAIN UNIT J231 L174 J601 J160 J161 TO DRIVE TO DRIVE BOARD BOARD...
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8-3 PLL UNIT • PLL UNIT (TOP VIEW) TO MAIN J281 TO MAIN J791 P991 TO PA UNIT J621 P891 J252 TO MAIN J1431 J254 DRES PDST CON2 CON1 CON0 PBST MLLV AFGC DSPS AFBP POWS DINT IMST FSKK TO MAIN J1381 P681 J253...
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8-5 FILTER UNIT • FILTER UNIT (TOP VIEW) BOTA SENO1 AFOUT 138A SENO2 DOUT PTTP MODA SQSA 10 6 9 5 TO MAIN UNIT J461 TO MIC RTTY REMOTE DATA (HPAO) (HRX) TO PA UNIT J172 TO MAIN BOARD J101 TO MAIN BOARD J431 8 - 11...
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SECTION 9 SECTION 9 BLOCK DIAGRAM BLOCK DIAGRAM FI511 ATT D522 ATT D521 FL-261 FILTER UNIT ATT D572 XTAL HFOR CTRL BUFF IC521 FI561 1.6 MHz D561 MA862 D271 10 dB Q111 DTC114EE 0.03-2.0 MHz IC571 D551 HPF BOARD µPC1688 69.0115 MHz IC1B D562 MA862...
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SECTION 10 VOLTAGE DIAGRAM SECTION 10 VOLTAGE DIAGRAM ¡ ¡ FRONT UNIT • FRONT UNIT VR BOARD RV-300 (AF) R9 10k PRAK R117 R123 390 (RF/SQL) DAP222 MENK (MENU) (P.AMP R118 R124 390 (RIT) /ATT) 1.5k R125 390 (PHONE) DLC-8309YBGF (F-1) (SHIFT) PRED...
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• MAIN UNIT MAIN (1) 4.6 V 40.0—59.999999 MHz 11.6V 2.0—3.999999 MHz 4.6 V 22.0—29.999999 MHz 11.6 V 4.0—7.999999 MHz 4.6 V 8.0—14.999999 MHz 4.6 V D351 0.03—1.999999 MHz J101 DAN221 15.0—21.999999 MHz 4.6 V L195 D191 L197 C193 C195 L194 R194 30.0—39.999999 MHz...
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¡ ¡ MAIN UNIT ¡MAIN UNIT MAIN (2) MAIN UNIT (1) WFM: 4.2 V WFM: 4.2 V WFM: 0.95 V C501 L501 C503 L503 C506 L602 L603 AT13 L435 4.7uH D500 WFM: 0 V WFM: 1.25 V R619 AT13 1SV308 0.56uH 0.56uH 0.0047...
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• MAIN UNIT MAIN (3) MAIN UNIT (2) DRIV DRIV HFOR HFOR VFOR VFOR UFOR UFOR AMS8 HREF HREF WFMB VREF VREF UREF UREF STRT STRT C899 R912 R913 D772 R772 CIVE CIVE 0.001 100k IC811b MA2S111 D732 FSKK BAND FSKK UMC3N DASH...
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MAIN UNIT (4) AMS8 WFM8 5.9 V FMS8 D732 UMC3N UNF8 D721 FI671 3.9 V C662 C571 MA862 FL-272 0.0047 0.0047 5.8 V C741 6.1 V 0.0047 C722 R722 5.6k L741 L731 D672 D671 LS-516 LS-516 MA862 MA862 Q721 2SC4081 R673 Q731 2F23...
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• MAIN UNIT MAIN (3) MAIN UNIT (2) DRIV DRIV HFOR HFOR VFOR VFOR MAIN UNIT (4) UFOR UFOR AMS8 HREF HREF WFMB VREF VREF UREF UREF STRT STRT AMS8 WFM8 C899 R912 R913 D772 R772 CIVE 5.9 V CIVE 0.001 100k IC811b...
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• FILTER UNIT CP101 C189 C190 LA-246 LA-236 4.0~7.999999 M MAIN (1) LR-216 LR-216 7MHz CONNECT:4.2 2SC4081 J101 NO CONNECT DTA114EE 0.75p 1SV312 MA2S111 C184 C185 AG20B44 MZ-12D-K 100uH MZ-12D-K 100p 30.0~59.99 CONNECT NO CONN C6 0.0047 100uH C16 0.0047 50MHz 2SC4081 1SS302...
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C136 0.68 HOUT [ANT1] 4.0~7.999999 MHZ CONNECT:4.2 V 7MHz 2SC4081 NO CONNECT:0 V LR-391 30.0~59.999999 MHZ CONNECT:4.2 V NO CONNECT:0 V 50MHz 2SC4081 1SS375 1SS375 22.0~29.999999 MHZ CONNECT:4.2 V NO CONNECT:0 V 470p 470p 24MHz 2SC4081 28MHz ATT ON:11.5 V ATT OFF:0 V 8.0~14.999999 MHZ CONNECT:4.2 V...
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• FILTER UNIT CP101 C136 0.68 C190 C189 HOUT LA-246 LA-236 [ANT1] 4.0~7.999999 MHZ MAIN (1) LR-216 LR-216 CONNECT:4.2 V 7MHz 2SC4081 J101 NO CONNECT:0 V DTA114EE 0.75p 1SV312 C184 C185 100uH MA2S111 AG20B44 MZ-12D-K MZ-12D-K 100p LR-391 30.0~59.999999 MHZ CONNECT:4.2 V C6 0.0047 100uH...
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