Rtty Terminal Unit - Icom ic-751a Instruction Manual

5-4 RTTY TERMINAL
UNIT When
operating
RTTY,
connect
the
ACC CONNECTOR
pin
9 and
pin
8 (ground)
via a
high speed
relay
or
through
a level
converter for
conversion to
TTL
level
to
your
teletypewriter.
The
audio tones
for
your terminal
are available
from
pin
4 and
pin 8 (ground).
The
AF
output
level
is
about
300mVp-p
for an
S9
signal.
•USING
A
HIGH SPEED
RELAY
•USING
A
LEVEL
CONVERTER
•
USING
AN
AFSK GENERATOR
•
An
RTTY
Terminal Unit
for
AFSK
operation can
also be con-
nected
easily.
NOTE: Some
RTTY
Terminal
Units
may
require the use of
a
20dB
audio
preamplifier
between
pin
5 on
the
ACC
SOCKET
and
the
AFSK
signal
output from the Terminal
Unit to provide enough
drive for
full
RF
output
power
from
the transceiver.
The
pin
5
input
must
be approxi-
mately
150mV
rms.
Check your
RTTY
Terminal Unit Instruction Manual.
•
The
AFSK
signal
may
be
connected
to the
IC-751A
front panel
MIC
CONNECTOR
pin
1
instead of the
ACC CONNECTOR
if
the
Terminal Unit
output
is
not high enough.
An
extra stage
of
amplification
is
provided
in
the
transceiver
when
using the micro-
phone
connector.
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20
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