Ic-F4/S; Main Unit - Icom IC-F3 Service Manual

2-2 IC-F4/S

• MAIN UNIT

Low-pass filter circuit
APC control circuit
Microphone amplifier
circuit
Antenna switching
circuit (D1: MA77)
FM IF IC
(IC2: TA31136FN)
1st mixer circuit
(Q13: 3SK241 R)
Expander IC
(IC10: M62354GP)
PLL IC
(IC1: µPD3140GS)
Mute switch
(IC4: BU4066BCFV)
T/R switching
circuit (D3: MA77)
Power amplifier
(Q1: 2SK2595)
TOP VIEW
2 - 2
BOTTOM VIEW
Current detector circuit
RF amplifier
(Q12: 3SK239)
T/R switching circuit
(D4: MA77)
Crystal filter
(FI1)
PLL reference oscillator
(X1: 15.3 MHz)
VCO circuit
CPU (IC8)
EEPROM (IC7)