Icom IC-R8500 Service Manual page 17

MAIN
unit,
IC18
Pin
number
Port
name
Description
4
WFM
Outputs
WFM
mode
select
signal.
5
FM
Outputs
FM
mode
select signal.
6
/WFM
Outputs
non-WFM mode
select
signal.
7
SSB Outputs
SSB mode
select
signal.
11
FIL3
Outputs 15
kHz bandpass
filter
select
signal.
12
FIL2
Outputs 6
KHz bandpass
filter
select
signal.
13 Fill
Outputs
2.4
kHz bandpass
filter
select
signal.
14
AM
Outputs
AM
mode
select
signal.
PLL
unit,
IC1
Pin
number
Port
name
Description
11
RST
:
Outputs
reset
signal.
PLL
unit,
IC2
Pin
number
Port
name
Description
4
STRB
Outputs
strobe signal tor the
expander
IC(ICI).
11
STDB
Outputs
strobe signal
tor
the
BFO
circuit
(IC13).
12
STP2
Outputs strobe
signal for
the 2nd
LO
PLL
1C (tCiO).
13
STDA
Outputs
strobe signal
for
the
1st
LO
PLL
circuit
(IC3).
14
STPI
Outputs
strobe signal
for
the
1
st
LO
PLL
1C
(ICS).
RF-A
unit.
IC3
Pin
number
Port
name
Description
4
B1
Outputs
0.1 to
0.49999
MHz
bandpass
filter
select signal.
5
B2
Outputs
0.5
to
1.59999
MHz
bandpass
filler
select signal.
6 B3
Outputs
1.6
to
1.99999
MHz
bandpass
filter
select signal.
7
B4
Outputs
2.0
to
3.99999
MHz
bandpass
filter
select signal.
11
B5
Outputs
4.0 to
7.99999
MHz
bandpass
filter
select signal.
12
B6
Outputs
8.0
to
10.99999
MHz
bandpass
filter
select signal.
13
B7
Outputs
1 1
.0 to 1
4.99999
MHz
bandpass
filter
select signal.
14
B8
Outputs
15.0
to
21
.99999
MHz
bandpass
filter
select signal.
RF-A
unit,
IC4
Pin
number
Port
name
Description
4
ANSW
Outputs [ANT2]
select signal.
5
AT20
Outputs 20
dB
attenuator
control
signal.
6
B9
Outputs 22.0
to
29.99999
MHz
bandpass
filter
select
signal.
7
PREF
Outputs
1
0
dB
attenuator control
signal.
"High":
While
[10
dB]
Is
ON.
13
HF5
Outputs
HF5 V
regulator
circuit
control
signal.
14
PREO
Outputs
1
0
dB
attenuator
control
signal.
•'High":
White
[10
dB]
is
OFF.
CONV
unit,
IC10
Pin
number
Port
name
Description
4
ICON
Outputs
switching relay control
signal.
"High":
While
RF
signals
above
1025
MHz
are received.
5
5MON
Outputs
divider
circuit
(IC8)
and
LPF
(L43-L45)
control signal.
"High";
While 1025-1199.99999
MHz
signals are received.
6
5MOF
Outputs divider
circuit
(IC8)
and LPF
(L47-L49)
control signal.
"High":
While
RF
signals
above
1200
MHz
are
received.
7
2ATF
Outputs 20
dB
attenuator
control
signal.
"High"
:
While
(20
dB)
is
OFF.
12
2ATN
Outputs 20
dB
attenuator control
signal.
"High":
While
[20
dB]
is
ON.
13
1ATF
Outputs 10
dB
attenuator
control
signal.
"High":
White
(10
dB]
is
OFF.
14 1ATN
Outputs 10
dB
attenuator
control
signal.
"High":
While
(10
dB)
is
ON.
4-10