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SERVICE
MANUAL
VHF TRANSCEIVER
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INTRODUCTION This service manual describes the latest service information for the at the time of IC-F50/IC-F51 VHF TRANSCEIVER publication. MODEL VERSION SYMBOL U.S.A USA IC-F50 General GEN IC-F51 Europe EUR To upgrade quality, all electrical or mechanical parts and internal circuits are subject to change without notice or oblig- ation. DANGER NEVER connect the transceiver to an AC outlet or to a DC power supply that uses more than 8 V. Such a connection could cause a fire or electric hazard. DO
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TABLE OF CONTENTS SECTION 1 SPECIFICATIONS SECTION 2 INSIDE VIEWS SECTION 3 DISASSEMBLY INSTRUCTIONS SECTION 4 CIRCUIT DESCRIPITON 4-1 RECEIVER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4-2 TRANSMITER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 4-3 PLL CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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SECTION 1 SPECIFICATIONS ‘ ‘ GENERAL • Frequency coverage : 136.000–174.000 MHz • Mode : FM • Type of emission : VERSION WIDE MIDDLE NARROW [USA], [GEN] 11K0F3E (12.5 kHz) 16K0F3E (25.0 kHz) [EUR] 14K0F3E (20.0 kHz) 8K0F3E (12.5 kHz) • Number of conventional channels : 128 ch, 8banks • Antenna connector : SMA type (50 Ω ) • Operating temperature range : –30 ˚C to +60˚C (–22 ˚F to +140˚F) [USA], [GEN] –25 ˚C to +55˚C [EUR] • Power supply requirement : 7.2 V DC nominal (negative ground) • Current
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SECTION 2 INSIDE VIEWS MAIN UNIT • TOP VIEW BOTTOM VIEW +5 Regurator Antenna (IC9: NJM2870) switching circuit S5 Regulator (D2,D5: 1SV307) Q23: 2SB1132 Power amplifier Q24: XP6501 (Q7: RD07MVS1) Q25: DTA144EU TX/RX APC amplifier T5 Regulator switch (IC2: TA75S01F) (Q21: 2SA1577) (D14,D15: MA2S077) VCO circuit R5 Regulator D/A converter (Q22: 2SA1577) (IC6: M62363FP) Analog switch (IC13: BU4066BCFV) IF amplifier Baseband IC (Q4: 2SC4215) (IC10: AK2346) IF IC Expander IC *Scrambler IC (IC1: TA31
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SECTION 3 DISASSEMBLY INSTRUCTIONS REMOVING THE CHASSIS UNIT REMOVING THE FRONT UNIT • • 1 Unscrew 1 nut A, and remove 1 knob B. 1 Unscrew 4 screws M. 2 Remove 1 washer c, and unscrew 1 screw D. 2 Unsolder 11 points N. 3 Unscrew 2 screws E, and remove 2 washers F. 3 Unplug the connector O from J402 on the Front unit. 4 Unscrew 2 screws G. 4 Take off the front unit in the direction of the arrow. 5 Take off the chassis unit in the direction of the arrow. M 6 Remove the cable H from the chassis uni
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SECTION 4 CIRCUIT DESCRIPTION The RF signals from the bandpass filter are mixed with the 4-1 RECEIVER CIRCUITS 1st LO signals, where come from the RX VCO circuit via the 4-1-1 ANTENNA SWITCHING CIRCUIT attenuator (R26–R28), at the 1st mixer circuit (Q3) to pro- (MAIN UNIT) duce a 46.35 MHz 1st IF signal. The 1st IF signal is passed The antenna switching circuit functions as a low-pass filter through a monolithic filter (FI1) in order to obtain selection while receiving and a resonator circuit wh
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4-1-5 AF AMPLIFIER CIRCUIT • CTCSS AND DTCS The tone squelch circuit detects AF signals and opens the (MAIN AND FRONT UNITS) squelch only when receiving a signal containing a matching The AF amplifier circuit amplifies the demodulated AF sig- subaudible tone (CTCSS or DTCS). When tone squelch is in nals to drive a speaker. This transceiver employs the base use, and a signal with a mismatched or no subaudible tone band IC which is composed of pre-amplifier, expander, is received, the tone squelch
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4-2-2 MODULATION CIRCUIT (MAIN UNIT) The power detector circuit (D1) detects the transmit power output level and converts it into DC voltage. The output volt- The modulation circuit modulates the VCO oscillating signal age is at a minimum level when the antenna impedance is (RF signal) using the microphone audio signals. matched at 50 Ω and is increased when it is mismatched. The AF signals from the D/A converter (IC6, pin 3) change The detected voltage is applied to the differential amplifier t
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4-4-2 FRONT UNIT VOLTAGE LINE 4-3-2 VCO CIRCUIT (MAIN UNIT) The VCO circuit contains a separate RX VCO (Q14, D19, LINE DESCRIPTION D20) and TX VCO (Q13, D16, D17). The oscillated signal is Same voltage as VCC line on the MAIN unit is amplified at the buffer amplifiers (Q10, Q12) and is then applied to the FRONT unit via the J401, pins 1, applied to the T/R switch (D14, D15). Then the receive 1st VCC 2 (FRONT unit). The voltage is supplied to the LO (Rx) signal is applied to the 1st mixer (Q3) an
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4-6 PORT ALLOCATIONS 4-5 OTHER CIRCUITS 4-6-1 EXPANDER IC (FRONT UNIT; IC410) 4-5-1 COMPOUNDER CIRCUIT (MAIN UNIT) IC-F50/F51 have compounder circuit which can improve S/N Pin Port Description ratio and become wide dynamic range to suppress the number name transmitting signal and to extend receiving signal. The circuit Outputs RX LED control signal. is composed of the base band IC (MAIN unit; IC10). 4 LEDR Low: Lights ON. (1) IN CASE OF TRANSMITTING Outputs TX LED control signal. 5 LEDT The audi
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4-6-2 MAIN CPU (FRONT unit; IC401) Pin Port Pin Port Description Description number name number name 1–11, SEG23– Input port for the PTT switch detection SEG13, signal. 45 PTT Output segment data to the LCD dis- Low:While the PTT switch is 13, SEG12, play. pushed. 15–25, SEG11– 46 KR1 Input ports for the key return A/D sig- SEG1 47 KR0 nals. Outputs serial data to the PLL IC Input port for the detect signal for con- 26 SO (MAIN unit; IC6, pin 8) and D/A con- 48 BATV necting battery pack’s voltag
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4-6-3 EXPANDER IC (FRONT UNIT; IC410) 4-6-5 EXPANDER IC (MAIN UNIT; IC12) Pin Port Pin Port Description Description number name number name Outputs RX LED control signal. Outputs the R5 regulator (Q22) control 4 LEDR Low: Lights ON. 4 R5C signal. Low: While receiving. Outputs TX LED control signal. 5 LEDT Low: Lights ON. Outputs the T5 regulator (Q21) control 5 T5C signal. Outputs back light LED control signal. Low: While transmitting. 6 LIGT Low: Back light is ON. Outputs the S5 regulator (Q23–
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SECTION 5 ADJUSTMENT PROCEDURES 5-1 PREPARATION When adjusting IC-F60/F61, the optional CS-F50 ADJ ADJUSTMENT SOFTWARE (Rev. 1.0 or later), *OPC-966 JIG CABLE (modified OPC-966 CLONING CABLE) are required. REQUIRED TEST EQUIPMENT EQUIPMENT GRADE AND RANGE EQUIPMENT GRADE AND RANGE Output voltage : 7.5 V DC Frequency range : 300–3000 Hz DC power supply Audio generator Current capacity : 5 A or more Output level : 1–500 mV Frequency range : DC–600 MHz Power attenuation : 40 or 50 dB FM deviation
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• SCREEN DISPLAY EXAMPLE CS-F50 ADJ Rev.1.0 File Option 2 COM 1: OPEN Connect Reload (F5) Disp para 1 [A / D] [D / A] 4 VIN : 203 : CBh : 7.96 V BPF T1 : 108 : 6Ch : 2.12 V 3 TEMPS : 190 : BEh : 32.23 'C T2/POW : 103 : 67h : 2.02 V 5 LVIN : 110 : 6Eh : 2.16 V REF : 137 : 89h : 2.69 V SD : 31 : 1Fh : 0.61 V MOD BAL : 0 : 00h : 0.00 % S MTR : Dev : 0 : 00h : 0.00 V CTCSS : 0 : 00h : 0.00 V SQL Lev : 100 : 64h : 39.22 % LVA : 136 : 88h : 2.67 V 6 CH No. : 01 RX Freq = 400.000000, TX =
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• CONNECTION Standard signal generator to the antenna connector 0.1 µ V to 32 mV (–127 dBm to –17 dBm) FM Attenuator deviation meter 40 dB or 50 dB CAUTION! DO NOT transmit while RF power meter to SSG is connected to 0.1–10 W/50 Ω the antenna connector Frequency counter Personal computer to an RS-232C port IC-F50/F51 Audio generator DB9 female plug SINAD meter (incl. level converter circuit) *OPC-966 RS-232C cable (straight) (JIG CABLE) Speaker (8 Ω ) • *OPC-966 (JIG CABLE) Add a jumper wire
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5-2 SOFTWARE ADJUSTMENTS (TRANSMITTING) Select an operation using [↑] / [↓] keys, then set specified value using [←] / [→] keys on the connected computer keyboard. MEASUREMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION PLL LOCK 1 • Operating CH : CH3 Soft Check the “LV” item on the CS- 3.5 V VOLTAGE • Receiving ware F50 ADJ’s display. [LV (RX LVA)] 2 • Operating CH : CH3 3.5 V [LV (TX LVA)] • Transmitting 3 • Operating CH : CH11 Soft Check the “LV” item on the CS- 0.9–1.5 V • Receiving
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SOFTWARE ADJUSTMENTS (RECEIVING) • Select an operation using [↑] / [↓] keys, then set specified value using [←] / [→] keys on the connected computer keyboard. • Need to adjust “S-METER ADJUSTMENT” after “RX SENSITIVITY ADJUSTMENT” is adjusted. Otherwise, “S-METER ADJUSTMENT” will not be adjusted properly. MEASUREMENT ADJUSTMENT ADJUSTMENT CONDITION VALUE UNIT LOCATION RX 1 • Operating CH : CH11 MAIN Connect a SINAD meter with an Minimum distortion SENSITIVITY • Connect a standard signal generato
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SECTION 6 PARTS LIST [VR BOARD] [FRONT UNIT] REF ORDER REF ORDER DESCRIPTION M. DESCRIPTION M. NO. NO. NO. NO. R601 7210003130 VARIABLE TP76N97N-13F-10KA-2497 T X401 6050011720 S.XTAL CR-764 (19.6608 MHz) T W601 8900012340 CABLE OPC-1260 T R401 7030005220 S.RESISTOR ERJ2GEJ 223 X (22 kΩ) T R402 7030005060 S.RESISTOR ERJ2GEJ 333 X (33 kΩ) T R403 7030005120 S.RESISTOR ERJ2GEJ 102 X (1 kΩ) T EP601 0910056532 PCB B 6034B R404 7030005120 S.RESISTOR ERJ2GEJ 102 X (1 kΩ) T R405 7030007340 S.RESISTOR ER
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[FRONT UNIT] [FRONT UNIT] REF ORDER REF ORDER DESCRIPTION M. DESCRIPTION M. NO. NO. NO. NO. R494 7030008010 S.RESISTOR ERJ2GEJ 123 X (12 kΩ) T C490 4030017460 S.CERAMIC ECJ0EB1E102K T R495 7030008010 S.RESISTOR ERJ2GEJ 123 X (12 kΩ) T C491 4030017460 S.CERAMIC ECJ0EB1E102K T R496 7030005050 S.RESISTOR ERJ2GEJ 103 X (10 kΩ) T C492 4030017460 S.CERAMIC ECJ0EB1E102K T R497 7030005050 S.RESISTOR ERJ2GEJ 103 X (10 kΩ) T C493 4030016930 S.CERAMIC ECJ0EB1A104K T R500 7030005090 S.RESISTOR ERJ2GEJ 104 X
