Output Expander Ics - Icom IC-821H Service Manual

CPU (DISPLAY UNIT, IC1; continue)
MAIN unit, IC10
Pin
Port
number
name
Description
Pin Port
number name
Description
79 EKEY Output port for electronic keyer signal.
81 MET
Outputs meter signals with a PWM
wave form.
82,83
DIUP,
Input ports for the main dial using
pulse signals.
4 NB
Outputs noise blanker control signal.
"High": Noise blanker activates.
5 SATL
Outputs control signal for satellite
mode.
EDOT,
Input ports for electronic keyer,
84,85
EDSH
"EDOT" for dot and "EDSH" for dash
signal.
Outputs audio select signal.
6
MSC
"High": MAIN band's audio signals
are selected.
90
ADSSM
Input port for SUB band's S-meter
signal.
11 SDOFF
Outputs PTT disable signal to ignore
SEND input from the ACC connector.
91 ADSCM
Input port for SUB band's center
indicator signal.
92 ADSMS
Input port for MAIN band's S-meter
signal.
93
ADMCM
Input port for MAIN band's center
indicator signal.
94 ADSNO
Input port for SUB band's noise level
signals.
Outputs UHF transmitter circuit control
12 BT8
signal.
"High": Transmitting on UHF.
Outputs both VHF and UHF receiver
13 R8
circuit control signals.
"High": Receiving on VHF/UHF.
Outputs VHF transmitter circuit control
95 ADMNO
Input port for MAIN band's noise level
signals.
14 AT8
signal.
"High": Transmitting on VHF.
96
ADRF Input port for Tx RF level signal.
97 ADALC Input port for ALC level signal.
98 ADPTT
Input port for [PTT) switch.
99
ADMIC
Input port for up/down signal from the
microphone.
MAIN unit, IC24
Pin Port
number name
Description
~54
OUTPUTEXPANDERICs
4
SCWN
Outputs CW-N mode select signal for
SUB band.
MAIN unit, Ica
5 SCW
Outputs CW mode select signal for
SUB band.
Pin Port
number name
Description
6 SSSB
Outputs SSB mode select signal for
SUB band.
4 MCWN
Outputs CW-N mode select signal for
MAIN band.
Outputs AGC time constant control
7 SAGC
signal for SUB band.
"High": AGC fast is selected.
5 MCW
Outputs CW mode select signal for
MAIN band.
11 SSCN Outputs scan signal for SUB band.
6 MSSB
Outputs SSB mode select signal for
MAIN band.
12 TSFM
Outputs switching signal of tone
squelch filter for SUB band.
Outputs AGC time constant select
7 MAGC
signal for MAIN band.
13 /SFM
Outputs FM mode select signal for
SUB band.
"High": AGC fast is selected.
11 MSCN Outputs scan signal for MAIN band.
14
SFM
Outputs non-FM mode select signal
for SUB band.
12 TSFM
Outputs switching signal of the tone
squelch filter for MAIN band.
13 /MFM
Outputs non-FM mode select signal
for MAIN band.
14 MFM
Outputs FM mode select signal for
MAIN band.
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