Icom IC-A24 Service Manual

1 - 2
4-5 PORT ALLOCATIONS
4-5-1 CPU (LOGIC unit; IC1)
Pin
number
Port
name
Description
1 PCON
Outputs control signal for the 5 V
regulator (IC16, Q4, Q6, Q7, D10).
2 VORS Input port for the 30 Hz phase signal.
3 VORC
Input port for the VOR 30 Hz standard
signal.
4 BPCPI
Outputs the bias control signal for a
type of battery.
5 LIGHT Input port for [LIGHT] switch.
6 CLIN Input port for the cloning signal.
7 CLOUT Outputs the cloning signal.
10 EDATA
I/O port for data signal from/to the
EEPROM (LOGIC unit; IC7)
11 ECK
Outputs clock signal to the EEPROM
IC (LOGIC unit; IC7).
12 POWER Input port for [POWER] switch.
13 PTT
Input port for [PTT] switch.
High: While [PTT] switch is
pushed.
14 UNLK
Input port for the PLL unlock signal.
Low: PLL is unlocked.
17 DCC
Input port for the external DC connec-
tion detection.
25 RESET Input port for the CPU reset signal.
28 VORD
Input port for the VOR signal detec-
tion.
29 RSSI Input port for the receive signal level.
30 RFDETV
Input port for the power detection of
power amplifi er (RF unit; Q2).
31 THRMC
Input port for the transceiver's internal
temperature.
32 SBATT
Input port for the battery type detec-
tion.
34 VIN
Input port for the battery voltage de-
tection.
38 BEEP Outputs BEEP audio signals.
109 PSTB
Outputs strobe signal to the PLL IC
(RF unit; IC3).
110 PDATA
Outputs data signals to the PLL IC (RF
unit; IC3).
111 PCK
Outputs clock signal to the PLL IC (RF
unit; IC3).
112 TXC
Outputs control signal to the T5 regu-
lator circuit (Q7, Q8, D8).
115 JACKDET
Input port for external SP jack con-
nection detection.
High: While external SP jack is
connected.
119, 120
DICK,
DIUD
Input ports for [DIAL].
4-5-2 EXPANDER (RF unit; IC5)
Pin
number
Port
name
Description
4 AFC
Outputs control signal to the AF out
controller (Q35, Q36) for AF amplifi er
(IC6).
5 ALCC
Outputs control signal to the ALC con-
troller (Q52).
6 R5C
Outputs control signal to the R5V
regulator (Q20).
7 ANLC
Outputs control signal to the ANL
switch (Q21).
11 MMUT
Outputs control signal for MIC mute
switch (Q51).
12
DET-
MUT
Outputs detector mute signal to the
AM/FM switch (IC2, pin 2).
13 SHIFT
Outputs shift control signal to the
VCO switch (Q57).
14 WXC
Outputs AM/FM (WX ch) select signal
to the AM/FM switch (IC2, pin 5).
4-5-3 EXPANDER (RF unit; IC17)
Pin
number
Port
name
Description
2, 3,
10, 11
T1–T4
Outputs the bandpass filter tuning
control signal.
14 MOD70
Outputs modulation control signal to
the buffer-amplifi er (IC18).
15 MOD30
Outputs modulation control signal to
the ALC amplifi er (IC19).
23 VOL
Outputs AF volume control signal to
the AF amplifi er (IC6).

Icom IC-A24 Specifications

General

Brand	Icom
Model	IC-A24
Category	Transceiver
Language	English