Icom IC-M73, Service Manual

Page: 13 / 35

4 - 5
Pin
No. Port
Name
Description I/O
106
MIC1/
SPCTRL
• While transmitting:
MIC gain controller (Q450 and Q451)
control.
( T h e m i c r o p h o n e s e n s i t i v i t y i s
determinded by the combination of
output voltage of "MIC1
− MIC3.")
• While receiving:
Analog switch (IC430, pins 6, 12) control.
O
107
MIC2/
AFVCTRL
• While transmitting:
MIC gain controller (Q450 and Q451)
control.
• While receiving:
AF amplifi er power supply circuit (Q230,
Q231, Q401 and Q540) control.
O
108
MIC3/
BPCTRL
• While transmitting:
MIC gain controller (Q450 and Q451)
control.
• While recseiving:
AquaQuake function control.
"Low": AquaQuake function is activated.
O
109 SQL
Input port for the [SQL] key (RF UNIT:
S250).
"Low": While the [SQL] key is pushed.
I
110 UP
Input port for the [ ] key (MAIN UNIT:
S321).
"Low": When the [ ] key is pushed.
I
111 DOWN
Input port for the [ ] key (MAIN UNIT:
S322).
"Low": When the [ ] key is pushed.
I
112 CH/WX
Input por t for the [CH/WX] key (MAIN
UNIT: S324).
"Low": When the [CH/WX] key is pushed.
I
113 16
Input port for the [16/C] key (MAIN UNIT:
S320).
"Low": When the [16/C] key is pushed.
I
114 SCAN
Input port for the [SCAN] key (MAIN UNIT:
S324).
"Low": When the [SCAN] key is pushed.
I
115 H/L
Input port for the [H/L] key (MAIN UNIT:
S329).
"Low": When the [H/L] key is pushed.
I
117 VOXM
AF mute switch (IC430, pin 5) control.
"High": While transmitting.
O
119 UNLK
PLL unlock signal from the PLL IC (IC1,
pin 5).
"High": While the PLL is unlocked.
I
• D/A CONVERTER (RF UNIT: IC190)
Pin
No. Port
Name
Description
2 MODC Deviation adjustment.
3 FCON Reference frequency adjustment.
10 PCON Transmit power setting voltage.
11 ATTS
Attenuator (RF UNIT: D94) switching signal.
"High"= The attenuator (RF UNIT: D94) is acti-
vated.
15 LOW
Transmit power setting signal.
"High"=TX power [High] or [Mid] is selected.
"Low"=TX power [LOW] is selected.
22
TCON/
LOW
• While receiving:
BPFs (RF UNIT: D130, L96, C110, C112 and
D131, L97, C114, C115) tuning voltage.
• While transmitting:
Transmit power setting voltage.
• CPU (MAIN UNIT: IC360) (continued)