Icom IC-751A Instruction Manual

®PREAMP/ATT
(Attenuator)
SWITCH
(§)MONITOR/MARKER
SWITCH
(§)MARKER
CALIBRATOR
(0MONITOR
LEVEL
CONTROL
(§)ANTI-VOX
CONTROL
This
switch
selects
the
RF
preamplifier to amplify
weak
receive
signals
or
the
RF attenuator
to
prevent overloading
of the
receiver.
Refer
to
SECTION 7
-
14 for
more
Information.
This
switch
turns
the
MONITOR or
MARKER
circuit
ON
or
OFF,
•
Vary
the
monitor
level with the
MONITOR
LEVEL
CONTROL.
•
A
calibration
marker is
generated
every
10kHz when
the
circuit is
activated.
This
control
varies
the marker
frequency.
Use
an accurate
standard
_
frequency
source
such
as
radio
station
WWV/WWVH
to
calibrate
the
marker generator.
See
SECTION
12-3
(2)
for more
information.
This
control
changes
the
audio
level of the
CW
sidetone
or SSB
monitor
circuit
when
the
MONITOR SWITCH
on
the top
panel is
turned
ON.
Adjust
the
control for
the
desired monitor
volume.
When
using
the
VOX
function,
sound
from
the
speaker may
cause
unwanted
switching
of the
T/R
relay.
Adjust
this control
in
con-
junction with
the
VOX
GAIN
CONTROL so
the T/R
relay
switches
only from
the
operator's
voice
and
not
from the
speaker
audio.
3-4
REAR
PANEL
©
#
@ANTENNA
CONNECTOR
Connect a
50
ohm
impedance
antenna to
this connector.
The con-
nector
mates
with
a
PL-259
plug.
®T/R
CONTROL
JACK
[RELAY]
(§)
EXTERNAL
ALC
JACK
[ALC]
(§) RECEIVE
ANTENNA
OUTPUT
[RECEIVE ANT OUT]
An output
signal
from this
jack
controls
the
transmit/receive
switch-
ing of
an
external
amplifier or
transverter.
NOTE:
DO NOT attempt
to
switch
greater
than 50
volts,
0.5
ampere.
This
jack accepts
an
automatic
level
control
signal
from an
external
amplifier or
transverter.
The ALC
voltage must
be
in the
range
of
0
volts to
—4
volts.
The receive
signals
from
the
ANTENNA
CONNECTOR pass
through
the
transmit/receive
antenna
switching
circuit
to
this jack.
Normally,
the
receiver
IN
and
OUT
jacks are
connected
together
with a
jumper.
The
ANTENNA
OUTPUT
JACK is
useful
when
operating
with
a
separate
receiver or an
external
preamplifier.
-
13
-

Icom IC-751A Specifications

General

Brand	Icom
Model	IC-751A
Category	Transceiver
Language	English