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1110003870 S.IC NJM2058M-T1 IC-7400 MAIN UNIT 5 pieces 6. DO NOT transmit power into a signal generator or a BiH M3 × 8 ZK IC-7400 8810005770 Screw Top cover 10 pieces sweep generator. Addresses are provided on the inside back cover for your 7.
SECTION 3 DISASSEMBLY AND OPTION INSTALLATIONS • Opening the transceiver’s case Follow the case and cover opening procedures shown here when you want to install an optional unit or adjust the internal units, etc. CAUTION: DISCONNECT the DC power cable from the transceiver before performing any work on the transceiver.
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• CR-338 HIGH STABILITY CRYSTAL UNIT By installing the CR-338, the total frequency stability of the transceiver will be improved. Shield cover q Remove the bottom cover as shown on the previous page. Earth spring w Remove the 4 screws from the shield cover of the RF unit, (CHASSIS) and disconnect P2 (CHASSIS) from J761 (MAIN unit), then lift up the shield cover.
SECTION 4 CIRCUIT DESCRIPTION • Used RF filter 4-1 RECEIVER CIRCUITS Frequency Control Input 4-1-1 RF SWITCHING CIRCUIT Filter component range signal diode (CTRL, RF AND PA UNITS) 0.03–1.6 MHz L11, L12, R11–R13, C12–C14, C17 The RF switching circuit leads receive signals to bandpass 1.6–2 MHz L21–L23, C21–C25 filters from an antenna connector while receiving.
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4-1-4 1ST MIXER AND 1ST IF CIRCUITS (RF UNIT) (Q204, Q205). The DC amplifiers function as an AGC circuit to reduce average noise. Therefore, the noise blanker func- The 1st mixer circuit mixes the received signals with the 1st tion shuts off pulse-type noise only. LO signal to convert the received signals into a fixed 64.455 MHz 1st IF signal.
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4-1-10 TWIN PBT CIRCUIT (DSP UNIT) 4-1-13 AF AMPLIFIER CIRCUIT (MAIN UNIT) General PBT (Passband Tuning) circuit shifts the center fre- The AF amplifier amplifies the audio signals to a suitable dri- quency of IF signal to electronically narrow the passband ving level for the speaker.
4-2 TRANSMITTER CIRCUITS The modulated IF signal from the DSP IC is applied to the D/A converter section in the CODEC IC (IC501) to convert 4-2-1 MICROPHONE AMPLIFIER CIRCUIT into the analog IF signal. Also the signal is level-shifted 3.3 (MAIN UNIT) V to 5V at the level converter section in the IC (IC501).
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The operating (transmitting) frequency is produced at the 1st When the FOR or VFOR signal exceeds the POCV voltage, IF mixer circuit (RF unit; D271) by mixing the 1st IF and 1st ALC bias voltage from the comparator controls the IF ampli- LO signals.
4-2-9 TEMPERATURE PROTECTION CIRCUIT 4-3-2 1ST LO PLL CIRCUIT (RF UNIT) (MAIN AND RF UNITS) The 1st LO PLL contains a main and reference loop as a dual loop system. The cooling fan (CHASSIS; MF1) is activated while transmit- ting or when the temperature of the power amplifier exceeds The reference loop generates an approximate 10.8 MHz fre- the preset value.
4-3-4 3RD LO CIRCUIT (RF UNIT) 4-4-2 DETECTOR CIRCUITS (CTRL UNIT) The DDS IC (IC1601) generates a 10-bit digital signal using (1) SWR detector the 32 MHz system clock. The digital signal is converted into Forward and reflected power are picked up by a current an analog wave signal at the D/A converter (R1601–R1620).
(1) CPU and EEPROM (CTRL unit) 4-5 POWER SUPPLY CIRCUITS The antenna tuner CPU (IC5) controls the tuning motors via 4-5-1 PA UNIT the motor driver circuit (Q211–Q218) and tuning relays di- Line Description rectly, and memorizes the best preset position in 100 kHz The voltage from an external power supply via steps.
SECTION 5 ADJUSTMENT PROCEDURES 5-1 PREPARATION BEFORE SERVICING I REQUIRED TEST EQUIPMENT EQUIPMENT GREDE AND RANGE EQUIPMENT GREDE AND RENGE Output voltage : 13.8 V DC Frequency range : 300–3000 Hz DC power supply Audio generator Current capacity : 30 A or more Measuring range : 1–500 mV Measuring range...
5-2 PLL ADJUSTMENTS ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST • Displayed freq. : Any Connect an RF volt- Maximum level L1903, REFERENCE FREQUENCY • Preset R1032 (RF unit) to the cen- meter to the check (0 dB or more) L1904, ter position.
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R1032 Reference frequency adjustment P1901 Reference frequency check point CP1500 1st LO outoput level check point CP1601 L1904 Reference 3rd LO output level L1901 frequency check point L1902 adjustment L1903 C1268 VCO lock C1248 voltage C1228 adjustment C1208 CP1801 (LV2) VCO lock voltage check point C1303...
5-3 TRANSMITTER ADJUSTMENTS ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST • Displayed freq. : 14.100000 MHz Connect an ammeter +2.5 A IDLING CURRENT • Mode : USB between the power (for driver) • [MIC GAIN] : Max.CCW supply and the IC- •...
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L251 C202 Idling current adjustment TX peak adjustment for HF/50 MHz bands final amplifier R204 Idling current adjustment for 144 MHz band Idling current adjustment final amplifier for driver J151 TX peak check point L330 L271 TX peak adjustment L251 TX peak adjustment L252...
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TRANSMITTER ADJUSTMENTS—continued ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST • Displayed freq. : 14.10000 MHz Rear Connect 100 W MAIN R306 HF BANDS OUTPUT • Mode : RTTY panel power meter POWER • [RF POWER] : Max. CW [ANT1] connector.
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R306 HF bands output power adjustment R311 L251 Residual AM 50 MHz band output power adjustment L252 adjustment R317 144 MHz band output power adjustment R320 AM carrier power adjustment SWR detector adjustment SWR detector check point CP1 (SETI) SWR detector pre-setting 5 - 7...
5-4 RECEIVER ADJUSTMENTS ADJUSTMENT MEASUREMENT POINT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION UNIT ADJUST • Displayed freq. : 14.100000 MHz Rear Connect an AC milli- Maximum audio output L252, RX PEAK • Mode : USB panel volt meter to [EXT level L251, •...
5-5 ADJUSTMENT MODE ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION ENTERING • Enter the adjustment mode: Push [F1 ( )] or [F2 ( )] to select D163E 0.70-0 q Turn power OFF. ADJUSTMENT each adjustment mode. 1.40-0 MODE w Terminate the [REMOTE] jack Once enterring adjustment mode, with a 3.5(d) mm mini-plug.
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ADJUSTMENT MODE—continued ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION Push [F5 ( )] to set and to step ADJUSTMENT next. chk SET DRIVE HF/50M Push [F5 ( )] to set and to step next. chk SET DRIVE 144M Push [F5 ( )] to set and to step next.
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ADJUSTMENT MODE—continued ADJUSTMENT ADJUSTMENT CONDITION DISPLAY OPERATION • Connect an SSG to [ANT 144M] Push [[F5 ( )] to tune the “BPF- Tuned BPF-1 ADJUSTMENT connector and set as: 1”, and to step next. chk SET Frequency : 108.021500 MHz Level : 3.2 µV (–97 dBm) Modulation...
[CTRL UNIT] [CTRL UNIT] ORDER ORDER DESCRIPTION DESCRIPTION 4030011340 S.CERAMIC C1608 CH 1H 471J-T-A 6910009670 S.CHECK P HK3-S-T 4030011600 S.CERAMIC C1608 JB 1E 104K-T-N 4030011600 S.CERAMIC C1608 JB 1E 104K-T-N 4030009990 S.CERAMIC C1608 CH 1H 200J-T-A 6510007020 CONNECTOR TMP-J01X-V6 4030009990 S.CERAMIC C1608 CH 1H 200J-T-A 6510007020 CONNECTOR TMP-J01X-V6...
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[DSP UNIT (MAIN UNIT EP2)] [DSP UNIT (MAIN UNIT EP2)] ORDER ORDER DESCRIPTION DESCRIPTION 1130010010 S.IC TC7WHU04FU R321 7030003520 S.RESISTOR ERJ3GEYJ 472 V (4.7 kΩ) ERJ3GEYJ 470 V (47 Ω) 1130010540 S.IC SN74AHC74PWR R322 7030003280 S.RESISTOR 1130010540 S.IC SN74AHC74PWR R323 7030003560 S.RESISTOR ERJ3GEYJ 103 V (10 kΩ) IC51...
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[DSP UNIT (MAIN UNIT EP2)] [DSP UNIT (MAIN UNIT EP2)] ORDER ORDER DESCRIPTION DESCRIPTION C164 4510004630 S.ELECTROLYTIC ECEV1CA100SR 7030003860 S.JUMPER ERJ3GE JPW V C171 4030011600 S.CERAMIC C1608 JB 1E 104K-T-N 7030008240 S.JUMPER ERJ12YJ0R00U C172 4030011600 S.CERAMIC C1608 JB 1E 104K-T-N 7030003860 S.JUMPER ERJ3GE JPW V C173...
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SECTION 7 MECHANICAL PARTS [FRONT UNIT] [MIC BOARD] REF. NO. ORDER NO. DESCRIPTION QTY. REF. NO. ORDER NO. DESCRIPTION QTY. 0880000950 Sensor EX-2500 #01 6510000190 Connector FM214-8SS (P) 6450001230 Plate HLJ0999-01-480 6450001230 Plate HLJ0999-01-480 8210018280 2072 front panel (A)-1 [7400] [PBT BOARD] 8210018270 2072 front panel (B)-1...
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• BOTTOM VIEW (DSP UNIT) MAIN unit J1001 J901 J902 MAIN unit J1000 DRIF DSPI1 DRES GND1 DRES KEYIN UNLK DSKY DSST DTAF DSPI2 GND1 GND1 OUT7 OUT8 OUT5 OUT6 VSQL DCBY OUT3 OUT4 TOFF RTDT MONI DAGC AGC2 AGC1 OUT1 OUT2 CTFL...
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9-11 RF UNIT • TOP VIEW J1001 J1601 to MAIN to MAIN unit J160 to MAIN unit J100 unit J400 P261 to MAIN unit J250 W254 from CTRL unit J2 from PA unit J1 P601 from PA unit J601 9 - 11...
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9-12 CTRL UNIT • TOP VIEW to TUNER unit J5 PAFE PAFE TUIN from TUNER unit J3 to CHASSIS to MAIN to RF unit J1 unit J741 T14V to TUNER unit MF2 T14V to TUNER unit MF1 C14V C14V C14V CT8V SETI C-8V...
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9-14 PA UNIT • TOP VIEW J202 to FILTER J201 unit EP5 V-B2 to VARISTOR-C to VARISTOR-D P601 board V-B1 board to RF unit J121 PPWS PDRS PFSB PMDT PMCK PH5V THML PT8V PVRF PVFR PGND PICL PICH P14A P14A P14V P14V P14V...
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9-15 FILTER UNIT 9-17 VARISTOR-A BOARD 9-19 VARISTOR-C BOARD • TOP VIEW • TOP VIEW • TOP VIEW to PA unit EP6 to CHASSIS P1 V-A2 V-B2 V-A1 V-B1 CHASSIS to PA unit EP7 9-16 DRV BOARD 9-18 VARISTOR-B BOARD 9-20 VARISTOR-D BOARD •...
12-5 PA UNIT, FILTER, DRV AND VARISTOR BOARDS PA UNIT J502 HPAO P501 FILTER BOARD MEASURMENT CONDITIONS CHASSIS 13.8V CT IN frequency:14.1MHz USB R702 RX(RF: no input) to CTRL L510 LA-551 L509 LA-481 TX(AF: no input) C237 144M TX: 0.68V 50MHz from/to RF 18/21MHz...
12-6 CTRL AND TUNER UNITS TUNER UNIT CTRL UNIT 100µH MP28GA R9 1M T14V T14V Q211 NY-12W-K-IE C1 2p from IC1b 13.6V CTIN DTC114EU 10µH PA unit NJM4558M J502 220k C3 20p Q212 13.6V DTC114EU MEASUREMENT CONDITIONS frequency: 14.1MHz USB T14V T14V RX(RF: no input)
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