8
1
PANEL DESCRIPTION
2001 NEW
D
DATA SOCKET
D
ACC SOCKETS
ACC (1)
PIN No. NAME
DESCRIPTION
SPECIFICATIONS
1
2
3
4
5
6
7
8
“High” level
: More than 2.4 V
1
RTTY Controls RTTY keying
“Low” level
: Less than 0.6 V
Output current
: Less than 2 mA
2
GND
Connects to ground.
Connected in parallel with ACC(2) pin 2.
Input/output pin.
(HF/50 MHz only)
Ground level
: –0.5 V to 0.8 V
3
HSEND Goes to ground when transmitting.
Output current
: Less than 20 mA
When grounded, transmits.
Input current (Tx)
: Less than 200 mA
Connected in parallel with ACC(2) pin 3.
4
MOD
Modulator input.
Input impedance
: 10 k
Ω
Connects to a modulator.
Input level
: Approx. 100 mV rms
AF detector output.
Output impedance : 4.7 k
Ω
5
AF
Fixed, regardless of [AF] position in
Output level
: 100–300 mV rms
default settings. (see notes below)
6
SQLS
Squelch output.
SQL open
: Less than 0.3 V/5 mA
Goes to ground when squelch opens.
SQL closed
: More than 6.0 V/100 µA
7
13.8 V 13.8 V output when power is ON.
Output current
: Max. 1 A
Connected in parallel with ACC(2) pin 7.
Control voltage
: –4 V to 0 V
8
ALC
ALC voltage input.
Input impedance
: More than 10 k
Ω
Connected in parallel with ACC(2) pin 5.
ACC (2)
PIN No. NAME
DESCRIPTION
SPECIFICATIONS
1
2
3
4
5
6
7
1
8 V
Regulated 8 V output.
Output voltage
: 8 V ±0.3 V
Output current
: Less than 10 mA
2
GND
Same as ACC(1) pin 2.
3
HSEND
Same as ACC(1) pin 3.
4
BAND
Band voltage output.
Output voltage
: 0 to 8.0 V
(Varies with amateur band)
5
ALC
Same as ACC (1) pin 8.
Input/output pin (144 MHz only)
Ground level
: –0.5 V to +0.8 V
6
VSEND Goes to ground when transmitting.
Output current
: Less than 20 mA
When grounded, transmits.
Input current (Tx)
: Less than 200 mA
7
13.8 V
Same as ACC(1) pin 7.
Rear panel view
Rear panel view
DATA
PIN No.
NAME
DESCRIPTION
1
2
3
4
5
6
1
DATA IN
Input terminal for data transmit. (1200 bps: AFSK/9600 bps: G3RUH, GMSK)
2
GND
Common ground for DATA IN, DATA OUT and AF OUT.
3
PTT P
PTT terminal for packet operation. Connect ground to transmit data.
4
DATA OUT Data out terminal for 9600 bps operation only.
5
AF OUT
Data out terminal for 1200 bps operation only.
Squelch out terminal. Becomes high (+8 V) when the transceiver receives a signal
which opens the squelch.
6
P SQL
• To avoid unnecessary TNC transmission, connect squelch to the TNC to inhibit trans-
mission when receiving signals.
• Keep audio output at a normal level, otherwise a “P SQL” signal will not be output.
Rear panel view
IC-746PRO.qxd 02.4.2 11:31 Page 8
Summary of Contents for i746PRO
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