Icom IC-701 Instruction Manual page 18

for MARK. For WIDE SHIFT, they are 2975Hz for
SPACE and 2125Hz for MARK. Also turn the P. B. Tune
control fully clockwise for clear reception.
5-4-2 TRANSMITTING
For Keying of the FSK (Frequency Shift Keying) circuit,
insert a high speed relay's coil into the loop current circuit
of the teletypewriter and connect the relay contacts to Pins
8 and 9 of the ACC socket on the rear panel. The relay
contacts make during the SPACE and break during the
MARK.
When a high speed relay is used
ACC SOCKET
When a level converter for TTL level signals is used, connect
the output of the converter to Pins 8 (ground) and 9 of the
ACC socket. Apply HIGH level (5V) signals for the MARK
and LOW (OV) signals for the SPACE. When using an
AFSK generator that has 2125Hz for MARK and 2295Hz
(2975Hz in wide shift) for SPACE, connect the output
signals for the AFSK generator to the MIC connector on
the front pane! and turn the MODE Select switch to the
LSB mode. In this case, you can use the VOX operation
available in the SSB mode, so receive to transmit change
over is very easy.
TTY
MACHINE
SELECTOR
MAGNETS
KEYBOARD
LOOP CURRENT
POWER SUPPLY
When a level converter is used
ACC SOCKET RITY
TTY
DEMODULATOR
MACHINE
MAGNETS
POWER SUPPLY
4 BREAK
yr SWITCH
LEVEL CONVERTER
tani nn din da Rah