4 - 7
4-6-2 FRONT CPU (FRONT UNIT; IC3)
Pin
number
Port
name
Description
7
RES
Input port for rest signal.
19–22
KR0–
KR3
I n p u t p o r t s fo r t h e 1 0 - k e y p a d .
(IC-F2800 series only)
28, 29
LIGT1,
LIGT2
Output control signals for LCD back-
light.
47
LEDT
Outputs control signal for the TX LED.
48
LEDR
Outputs control signal for the RX LED.
51, 52
DICK,
DIUP
Input ports for control signal from the
dial (S9). (IC-F2700 series only)
53, 54
KYUP,
KYDN
Input ports for control signal from [ ],
[ ] keys. (IC-F2800 series only)
57
HANG
Input port for the microphone hanger
detection signal.
Low:
While microphone on the
hanger.
58
PTT
Input port for the PTT switch of the
connected microphone.
59–63
KYP0–
KYP4
Input por ts for the programmable
function keys (P0–P4).
4-6-4 D/A CONVERTER (MAIN UNIT; IC30)
Pin
number
Port
name
Description
1
T1
Outputs the bandpass filters (D23,
D26, D68, D69) tuning signal.
2
T2
• While receiving
Outputs the bandpass filters (D17,
D18) tuning signal.
• While transmitting
Outputs the TX power control signal
which selects TX output power of
HIGH, LOW1 or LOW2. The output
signal is applied to the APC amplifi er
(IC37, pin 1).
3
TXLVA
Outputs TX VCO lock voltage.
4
RXLVA
Outputs RX VCO lock voltage.
4-6-3 D/A CONVERTER (MAIN UNIT; IC8)
Pin
number
Port
name
Description
2
SQL
Outputs AF signal to the squelch cir-
cuit (IC12, pin 8).
3
MOD
Outputs modulation signals to the
VCO circuit.
10
TENC
Outputs CTCSS/DTCS signals.
11
BAL
Outputs deviation balance control sig-
nal.
14
BEPV
Outputs beep audio signals to the
speaker via the AF amplifiers (IC34,
IC38).
15
SIGNAL
Outputs AF signals to the speaker via
the AF amplifi ers (IC34, IC38).
22
TONE
Outputs single tone signal.
23
REF
Outputs reference oscillator (X2) con-
trol signal.
LIGT1
LIGT2
LIGHT
HIGH
HIGH
DIM
HIGH
LOW
OFF
LOW
HIGH
ON
LOW
LOW
OFF
