INTRODUCTION This service manual describes the latest service information for the IC-F3GT and IC-F3GS at the time of publication. 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 16 V.
SECTION 1 SPECIFICATIONS Frequency coverage Type of emission Number of channels Power supply requirement at High at Low Current drain (approx.) rated audio stand-by Frequency stability Usable temperature range Dimensions (proj. not included) Weight (with BP-209) Output power Modulation system Max.
SECTION 2 • MAIN UNIT TOP VIEW Antenna swtching circuit (D1, D2, D8: MA77) Power amplifier (Q1: 2SK2974) Low-pass filter circuit IC3A: NJM2902V Q37: DTA144EU FM IF IC (IC2: TA31136FN(D)) IF amplifier (Q14: 2SC4215 O) Mic amplifier circuit PLL IC (IC1: PD3140GS) TX/RX switch (D3, D4: MA77)
SECTION 3 DISASSEMBLY AND OPTION INSTRUCTIONS 3-1 DISASSEMBLY INSTRUCTION • REMOVING THE CHASSIS PANEL 1 Unscrew 1 nut A, and remove 1 knob B. 2 Unscrew 2 screws C. 3 Take off the chassis in the direction of the arrow. 4 Unplug J6 to separate front panel and chassis.
3-2 OPTIONAL UNIT INSTALLATIONS 1 Remove the option cover. 2 Connect one of UT-96, UT-105, UT-108, UT-109, UT-110, and UT-111 optional unit to J5. 3 Replace the option cover to the chassis-hole. Option cover Option unit 3 - 2...
SECTION 4 CIRCUIT DESCRIPTION 4-1 RECEIVER CIRCUITS 4-1-1 ANTENNA SWITCHING CIRCUIT Received signals are passed through the low-pass filter (L1, L2, C1–C5, C8). The filtered signals are applied to the ⁄ type antenna switching circuit (D2, D8). The antenna switching circuit functions as a low-pass filter while receiving.
4-1-5 AF CIRCUIT AF signals from the FM IF IC (IC2, pin 9) are applied to the mute switch (IC4, pin 1) via the AF filter circuit (IC3b, pins 6, 7). The output signals from pin 11 are applied to the AF power amplifier (IC5, pin 4) after being passed through the [VOL] control (R143).
The signal output from the power detector circuit (D32, D33) is applied to the differential amplifier (IC3a, pin 2), and the “T4” signal from the expander (IC10, pin 11), controlled by the CPU (IC8), is applied to the other input for reference. When the driving current is increased, input voltage of the differential amplifier (pin 2) will be increased.
4-5 PORT ALLOCATIONS 4-5-1 CPU (IC8) Port Description number name Input port for battely voltage detection. RESET Input port for RESET signal. Outputs reference oscillator for the CSIFT CPU control signal. Outputs clock signal to the PLL IC (IC1), EEPROM (IC7), etc. •...
: 10 MΩ/V DC or better AC millivoltmeter STARTING SOFTWARE ADJUSTMENT q Connect IC-F3GT/GS and PC with the optional OPC-478 and the JIG cable. w Boot up Windows, and turn the transceiver power ON. e Click the program group ‘CS-F3G ADJ’ in the ‘Programs’...
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: Reload adjustment data : Receive sensitivity measurement : Connected DC voltage : PLL lock voltage : Operating channel select : RF output power ¥ JIG cable to IC-F3GT/GS [SP] jack Connect Reload (F5) [D / A] 7.73 V BPF T1 BPF T2 1.92 V...
• Connection Standard signal generator 0.1 V to 32 mV (–127 dBm to –17 dBm) CAUTION: DO NOT transmit while an SSG is connected to the antenna connector. Attenuator deviation meter 40 dB or 50 dB RF power meter 0.1–10 W/50 Frequency counter ¥...
5-2 PLL ADJUSTMENT ADJUSTMENT ADJUSTMENT CONDITIONS PLL LOCK • Operating frequency VOLTAGE 136.000 MHz (L-band) 146.000 MHz (H-band) • Receiving • Transmitting • MAIN unit RF power meter PLL lock voltage adjustment PLL lock voltage check point MEASUREMENT UNIT LOCATION MAIN Connect a digital multi meter to check point Bottom view...
5-3 SOFTWARE ADJUSTMENT Select an operation using [ ] / [ ] keys, then set specified value using [ ] / [ ] keys on the connected computer keyboard. ADJUSTMENT ADJUSTMENT CONDITION REFERENCE • Operating frequency: FREQUENCY [TXF] • High/Low switch •...
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SOFTWARE ADJUSTMENT – continued Select an operation using [ ] / [ ] keys, then set specified value using [ ] / [ ] keys on the connected computer keyboard. ADJUSTMENT ADJUSTMENT CONDITION 1 • Operating frequency: SENSITIVITY [BPF T1] – [BPF T4] •...
10-3 VOLTAGE DIAGRAM 13.77 V 10-4 BOARD LAYOUT 12.49 V 12.47 V 13.80 V R1 24 R5 10 k 2SB1201 S R2 24 11.82 V 11.80 V 13.63 V 12.46 V RN2404 DS1 TLG124A R4 10 k 0.23 V 1SS355 0.22 V 56 k RN1409...
SECTION 11 BLOCK DIAGRAM J5 AXN330C038 CR-664A [OTHER] CR-671A A, D (15.3 MHz) OPTION UNIT 2TONE or 5TONE MIC, AF, PTT, MMUT RMUT, AFONOP SIGOUT CONT Q17 UN911H Q15 2SB1132 R Q16 XP6501 AB D26 DAN202K IC5 TA7368F IC10 M62363FP-650C EXT.MIC MIC JACK Q31 DTC144TU...
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SECTION 12 VOLTAGE DIAGRAM AFOUT DISCIN AXN330C038 OPV1 OPV2 OPV3 CIRQ BUSY OPT3 OPT2 AFOUT OPT1 to Optional unit DISCIN SIGOUT RXMUTE RMUTE CPU5 MOWN BEEPOUT R131 BUSY AFONOP MICMUTE MMUTE MICIN MICOUT TX: 4.84 V UN911H PTTOUT RX: 0 V PTTIN C147 C154...
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AFOUT DISCIN VOLMIN — VOLMAX 3.31 V 7.23 V — 7.07 V TA7368F 2SB1132 R POUT TX: 0 V PWGND 4.62 V RX: 3.96 V PREGND PHASE 7 NF 6 R126 RIPPLE 94 V XP6501 AB 10 k R120 68 k R127 R122 2.7 k...
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4.03 V TX: 4.62 V 3.37 V RX: 0.04 V 0.1 H 0.001 4.7 k 0.1 H 3.3 k TX: 0.7 V 0.001 RX: 0.73 V 2SC5085 Y MA77 27 P 1.2 k MA77 82 nH TX: 0.8 V RX: 0 V C4215 O 27 K 68 A...
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SECTION 12 VOLTAGE DIAGRAM AFOUT DISCIN AXN330C038 OPV1 OPV2 OPV3 CIRQ BUSY OPT3 OPT2 AFOUT OPT1 DISCIN to Optional unit SIGOUT RXMUTE RMUTE R177 MOWN CPU5 C125 BEEPOUT C132 IC3C R266 0.0022 BU4066BCFV BUSY R131 15 k 0.0056 NJM2902V AFONOP TX: 3.69 V C217 C124...
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INTRODUCTION This service manual describes the latest service information for the IC-F4GT and IC-F4GS at the time of publication. 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 16 V.
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SECTION SPECIFICATIONS SECTION INSIDE VIEWS SECTION DISASSEMBLY AND OPTION INSTRUCTIONS DISASSEMBLY INSTRUCTION ..........3-1 OPTIONAL UNIT INSTALLATIONS .
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SECTION 1 SPECIFICATIONS Frequency coverage Type of emission Number of channels Power supply requirement at High at Low Current drain (approx.) rated audio stand-by Frequency stability Usable temperature range Dimensions (proj. not included) Weight (with BP-209) Output power Modulation system Max.
SECTION 3 DISASSEMBLY AND OPTION INSTRUCTIONS 3-1 DISASSEMBLY INSTRUCTION • REMOVING THE CHASSIS PANEL 1 Unscrew 1 nut A, and remove 1 knob B. 2 Unscrew 2 screws C. 3 Take off the chassis in the direction of the arrow. 4 Unplug J6 to separate front panel and chassis.
3-2 OPTIONAL UNIT INSTALLATIONS 1 Remove the option cover. 2 Connect one of UT-96, UT-105, UT-108, UT-109, UT-110, UT-111, and UT-113 optional units to J5. 3 Replace the option cover to the chassis-hole. Option cover Option unit 3 - 2...
SECTION 4 CIRCUIT DESCRIPTION 4-1 RECEIVER CIRCUITS 4-1-1 ANTENNA SWITCHING CIRCUIT The antenna switching circuit functions as a low-pass filter while receiving. However, its impedance becomes very high while D2 and D8 are turned ON. Thus transmit signals are blocked from entering the receiver circuits. The antenna switching circuit employs a ⁄...
4-1-5 AF CIRCUIT AF signals from the FM IF IC (IC2, pin 9) are applied to the mute switch (IC4, pin 1) via the AF filter circuit (IC3b, pins 6, 7). The output signals from pin 11 are applied to the AF power amplifier (IC5, pin 4) after being passed through the [VOL] control (R143).
The signal output from the power detector circuit (D32, D33) is applied to the differential amplifier (IC3a, pin 2), and the “T4” signal from the expander (IC10, pin 11), controlled by the CPU (IC8), is applied to the other input for reference. When the driving current is increased, input voltage of the differential amplifier (pin 2) will be increased.
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4-5 PORT ALLOCATIONS 4-5-1 CPU (IC8) Port Description number name Input port for battely voltage detection. RESET Input port for RESET signal. Outputs reference oscillator for the CSIFT CPU control signal. Outputs clock signal to the PLL IC (IC1), EEPROM (IC7), etc. •...
SECTION 5 ADJUSTMENT PROCEDURES 5-1 PREPARATION When you adjust the contents on page 5-5 or 5-6, SOFTWARE ADJUSTMENT, the optional CS-F3G ADJ (Rev. 2.0 or later), OPC-478 CLONING CABLE REQUIRED TEST EQUIPMENT EQUIPMENT GRADE AND RANGE Output voltage DC power supply Current capacity Measuring range RF power meter...
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CONNECTION Standard signal generator 0.1 V to 32 mV ( 127 dBm to 17 dBm) CAUTION: DO NOT transmit while an SSG is connected to the antenna connector. Attenuator deviation meter 40 dB or 50 dB RF power meter 0.1 10 W/50 Frequency counter DC POWER CABLE CONNECTIONS...
5-3 SOFTWARE ADJUSTMENT Select an operation using [ ] / [ ] keys, then set specified value using [ ] / [ ] keys on the connected computer keyboard. ADJUSTMENT ADJUSTMENT CONDITION REFERENCE • Operating frequency: FREQUENCY [TXF] • High/Low switch •...
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SOFTWARE ADJUSTMENT – continued Select an operation using [ ] / [ ] keys, then set specified value using [ ] / [ ] keys on the connected computer keyboard. ADJUSTMENT ADJUSTMENT CONDITION 1 • Operating frequency: SENSITIVITY [BPF T1] – [BPF T4] •...
10-3 VOLTAGE DIAGRAM 13.77 V 10-4 BOARD LAYOUT 12.49 V 12.47 V 13.80 V R1 24 R5 10 k 2SB1201 S R2 24 11.82 V 11.80 V 13.63 V 12.46 V RN2404 DS1 TLG124A R4 10 k 0.23 V 1SS355 0.22 V 56 k RN1409...
SECTION 11 BLOCK DIAGRAM J5 AXN330C038 OPTION UNIT 2TONE or 5TONE X4 CR-662 (15.3 MHz) MIC, AF, PTT, MMUT RMUT, AFONOP SIGOUT CONT Q17 UN911H Q15 2SB1132 R Q16 XP6501 AB D26 DAN202K IC5 TA7368F IC10 M62363FP-650C EXT.MIC MIC JACK Q31 DTC144TU AF OUT D27 RB706F-40...
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SECTION 12 VOLTAGE DIAGRAM AFOUT DISCIN AXN330C038 CPU5 OPV1 CPU5 OPV2 OPV3 CIRQ CPU5 OPT3 OPT2 AFOUT OPT1 Tx: 4.79 V to Optional unit DISCIN Rx: 0.00 V SIGOUT RXMUTE RMUTE MOWN BEEPOUT C554 BUSY 470 P AFONOP MICMUTE BUSY MMUTE R510 MICIN...
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AFOUT DISCIN CPU5 CPU5 AFON AF min 7.23 V AF max 7.03 V TA7368F 3.31 V 2SB1132 R POUT PWGND Tx: 2.20 V PREGND Rx: 2.21 V PHASE 7 AFON NF 6 R126 RIPPLE 3.96 V 10 k R127 R122 R120 2.7 k R178...
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C471 47 P 10 k R445 C670 470 P C472 47 P L411 10 nH C Tx: 3.64 V 27 nH B 12 nH J Rx: 0.19 V 15 nH F 22 nH [OTHER] 18 nH K 22 nH B 4.7 k 0.001 470 P...
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SECTION 12 VOLTAGE DIAGRAM AFOUT DISCIN AXN330C038 CPU5 OPV1 CPU5 OPV2 OPV3 CIRQ CPU5 OPT3 Tx: 2.19 V OPT2 Rx: 2.20 V AFOUT OPT1 Tx: 2.19 V 2.5 Vp-p to Optional unit DISCIN Tx: 4.79 V C556 4 Vp-p Rx: 2.20 V ( a)1 kHz, –1.5 kHz) SIGOUT Rx: 0.00 V...
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