3 - 14
13
14
15
16
17
18
19
Outputs strobe signals for the out-
put expander ICs (RF-B unit; IC301,
IC302).
Outputs the antenna connector
([ANT1] or [ANT2]) select signal.
High :
When the [ANT2] is selected.
Outputs strobe signals for the output
expander (CTRL-A board; IC11).
Outputs strobe signals for the D/A
converter (IC3751).
Outputs strobe signals for the output
expander ICs (IC3752, IC3753).
Outputs control signal for the AF mute
switch (IC331).
High :
When the [AF] control is set to
maximum counter clockwidth.
Outputs squelch mute control signal,
applied to the squelch gate (IC301).
High : When squelch is closed.
BSTB
ANTS
FSTB
ASTB
MSTB
AFMS
SQLS
Pin
Port
Description
number
name
12
13
14
15
16
17, 18
Outputs squelch control signal for the
[MIC] and [ACC1] connectores.
High :
Squlch opend. (RX LED ON)
Outputs control signal for the internal
speaker ON/OFF select relay (RL351).
High : Internal speaker is ON.
Outputs strobe signals for the optional
UT-102 SPEECH SYNTHESIZER.
Outputs chip select signal for the
audio recoder (IC3001).
Outputs external antenna tuner (AH-3)
start signal.
Low :
When the [TUNE] switch is
pushed.
Outputs control signal for the DSP IC
(DSP-A board; IC2001).
SQSS
SPS
SSTB
VCS
ESTA
DSFR,
DSFW
Pin
Port
Description
number
name
4
6
7
12
14
Outputs control signal for the noise
blanker switch (Q3751, Q3752).
High :
When the [NB] switch is ON,
except in FM mode.
Outputs audio select signal for the TX
monitor function.
High :
During monitoring in SSB or
RTTY mode.
Outputs audio select signal for the TX
monitor function.
High :
During monitoring in AM or FM
mode.
Outputs analog switch (IC3005) con-
trol signal for the audio recoder’s
(IC3001) output.
High :
When the audio recoder’s out-
put to the AF circuit.
Outputs analog switch (IC3002) con-
trol signal for input of the microphone
amplifier (IC461).
High :
Except the microphone input is
selected.
NBS
MSL1
MSL2
VOSL
MISL
Pin
Port
Description
number
name
4
5
6
7
11
14
Outputs AM mode select signal for
the AGC and APC circuit.
High : When AM is selected.
Outputs HF band RF power control
signal.
High :
When 0.03–29.999999 MHz
band is selected.
Outputs 50 MHz band RF power con-
trol signal.
High :
When 30–60 MHz band is
selected.
Outputs 2nd IF filter (FI131 or FI133)
select signal.
High :
When transmitting in AM or FM
mode. (FI131 is ON)
Outputs reset signal for the DSP cir-
cuit and etc.
Outputs FM deviation control signal.
High : When FM-N is selected.
AMS
PHFS
P50S
MODS
DSRS
FMNS
Pin
Port
Description
number
name
(8) MAIN-A unit; IC3653
(10) MAIN unit; IC3752
(9) MAIN-A unit; IC3654
(11) MAIN-A unit; IC3753
