Input Expander Allocations - Icom IC-756PROIII Service Manual

3-7-4 INPUT EXPANDER ALLOCATIONS

(1) DISPLAY board; IC411
Pin Port
number name
Input port for the [RIT], [∆TX] and
KI4
1
[CLEAR] switches.
Input port for [UP] and [DN] switches
MUDK
5
of the connected microphone.
Input port for the [DUALWATCH],
KI3
12
[CHANGE], [V/M] and [M/S] switches.
I n p u t p o r t f o r t h e [ T U N E R ] ,
KI0
13
[MONITOR], [NB] and [NR] switches.
Input ports for the multi-function
KI1, KI2
14, 15
switches.
(2) MAIN-A unit; IC3652
Pin Port
number name
CTFL Input port transmission status for CW
11
RTDT Input port for RTTY decode data.
12
Input port for the KEY signal from the
EKEY connected AH-3.
13
Low : While tuning or tune NG
Input port for AH-3 connection detec-
TCON tion.
14
High : When AH-3 is connected.
Input port for interrupting signal
VINT
16
from audio recoder.
Input port for address clock signal
VRAC
17
from audio recoder.
Input por t for busy signal from
SBSY t h e i n s t a l l e d U T- 1 0 2 S P E E C H
18
SYNTHESIZER.
3-7-5 OUTPUT EXPANDER ALLOCATIONS
(1) PLL unit; IC1
Pin Port
number name
Outputs strobe signals to DDS IC
PST1
4
(IC101) for the 1st LO PLL A circuit.
Outputs strobe signals to PLL IC
PST2
5
(IC381) for the 1st LO PLL A circuit.
Outputs strobe signals to DDS IC
PST3
6
(IC401) for the 1st LO PLL B circuit.
Outputs strobe signals to PLL IC
PST4
7
(IC681) for the 1st LO PLL B circuit.
Outputs strobe signals to DDS IC
PST5
12
(IC701) for the 3rd LO PLL circuit.
Outputs strobe signals to PLL IC
PST6
13
(IC901) for the S2 LO PLL circuit.
Outputs strobe signals to DDS IC
PST7
14
(IC801) for the S3 LO PLL circuit.
Description
Description
Description
(2) PLL unit; IC101
Pin Port
number name
MAKS
66
PAMT
68
PAFS
70
VA4S
71
VA3S
73
VA2S
74
VA1S
75
(3) PLL unit; IC401
Pin Port
number name
PBMT
68
PBFS
70
VB4S
71
VB3S
73
VB2S
74
VB1S
75
3 - 12
Description
Outputs the marker mute switch
(IC192) control signal.
High : When the marker ON is select-
ed.
Outputs LO mute switch (Q361) con-
trol signal.
Low : Muted
Outputs bandpass filter select switch
(Q351) control signal.
High : When less than 8 MHz is dis-
played on the main band.
Outputs the LO switch (Q121) control
signal.
High : While 45.0–60.0 MHz band is
displayed on the main band.
Outputs the LO switch (Q122) control
signal.
High : While 20.0–44.999999 MHz band
is displayed on the main band.
Outputs the LO switch (Q123) control
signal.
High : While 8.0–19.999999 MHz band
is displayed on the main band.
Outputs the LO switch (Q126) control
signal.
High : While 0.03–7.999999 MHz band
is displayed on the main band.
Description
Outputs LO mute switch (Q661) control
signal.
Low : Muted
Outputs bandpass filter select switch
(Q651) control signal.
High : When less than 8 MHz is dis-
played on the main band.
Outputs the LO switch (Q421) control
signal.
High : While 45.0–60.0 MHz band is
displayed on the main band.
Outputs the LO switch (Q422) control
signal.
High : While 20.0–44.999999 MHz band
is displayed on the main band.
Outputs the LO switch (Q423) control
signal.
High : While 8.0–19.999999 MHz band
is displayed on the main band.
Outputs the LO switch (Q426) control
signal.
High : While 0.03–7.999999 MHz band
is displayed on the main band.