Icom IC-F50 Service Manual Addendum page 32

4-6-3 EXPANDER IC (FRONT UNIT; IC410)
Pin Port
number name
Outputs RX LED control signal.
4 LEDR
Low: Lights ON.
Outputs TX LED control signal.
5 LEDT
Low: Lights ON.
Outputs back light LED control signal.
6 LIGT
Low: Back light is ON.
Outputs audio control signal.
7 AFON Low: Outputs audio signals from
• Outputs CTCSS/DTCS switching
signal when transmitting.
High: Selected DTCS.
• Outputs Min. VR switching signal
when receiving.
11 DUSE
Low: Select Min VR.
NOTE: Audio signals are prior to
Outputs microphone select signal.
High: While the internal microphone
12 MCON
Outputs shift signal for reference
13 CSFT
oscillator's frequency.
Outputs the internal speaker control
signal.
14 SPON
High: T h e i n t e r n a l s p e a ke r i s
4-6-4 D/A CONVERTER IC (MAIN UNIT; IC6)
Pin Port
number name
Outputs the modulation balance level
11 BAL control signal. The signal is applied to
the buffer amplifier (IC16, pin 2).
• Outputs the bandpass filter tuning
signal. The output signal is applied
14 T2 to the bandpass filters (D9, D10).
• Outputs the TX power control signal.
The output signal is applied to the
APC amplifier (IC2, pin 1).
Outputs the bandpass filter tuning
15 T1 signal. The output signal is applied to
the bandpass filters (D4, D8).
Outputs the PLL lock voltage control
22 LVA signal. The output signal is applied to
the buffer amplifier (IC16, pin 5).
Outputs the reference oscillator
23 REF correcting voltage. The voltage is applied
to the buffer amplifier (IC16, pin 3).
Description
speaker.
transmitting.
is used.
selected.
Description
4-6-5 EXPANDER IC (MAIN UNIT; IC12)
Pin Port
number name
4 R5C
5 T5C
6 LIGT
7 AFON
11 MUT2
12 MUT1
13 PMFM
14 TMUT
4 - 7
Description
Outputs the R5 regulator (Q22)
control signal.
Low: While receiving.
Outputs the T5 regulator (Q21) control
signal.
Low: While transmitting.
Outputs the S5 regulator (Q23–Q25)
control signal.
Low: While the S5 regulator outputs
5 V voltage.
Outputs audio control signal.
Low: Outputs audio signals from
speaker.
Outputs the analog switch (IC13,
pins 5, 6) control signal to control the
scrambler unit.
High: While the scrambler function is
ON.
Low: While the microphone mute or
AF mute is ON.
Outputs the analog switch (IC13, pins
12, 13) control signal to control the
scrambler unit.
High: While the scrambler function is
ON.
Low: While the microphone mute or
AF mute is ON.
Outputs the FM/PM modulation
switching signal to the FM/PM switch
(IC11, pin 5).
High: PM is selected.
Outputs the transmitting mute switch
control signal to the mute switch (D25).
High: While muting.