Receiver Controls; And Switches - Icom IC-725 Instruction Manual

4
PRE-OPERATION
4-4 RECEIVER
CONTROLS
AND
SWITCHES
Adjust the following controls
and switches
on
the front
panel
for
optimum
reception.
SQUELCH CONTROL
Mutes the speaker. Signals
and noises that are stronger
than the squelch threshold
level
open
the squelch
and
audio
is
emitted
from
the speaker.
AF GAIN
CONTROL
Varies the audio
output
level
from
the speaker.
Clockwise
rotation increases the volume.
RIT
CONTROL
Used
for fine tuning stations
which
call
off
frequency
or for
compensating
for
frequency
drift.
Shifts the receive frequency
up
to
±1
kHz
from
the
displayed
frequency without
shifting
the transmit
frequency.
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CW/N SWITCH
By
installing
an optional
CW
narrow
filter.
The
transceiver
has better
receive selectivity in
CW
mode.
AGC
SWITCH
Out
position:
AGC
slow
Normally
used
when
operating
in
SSB
or
AM
mode.
In position:
AGC
fast
Normally used
when
operating
in
CW
mode.
Note
that the
AGC
switch
does not function
in
FM
mode.
PREAMP SWITCH
Used
when
receiving
weak
signals.
Push
[PREAMP]
to the
IN position
to
improve
the
S/N
ratio
and
sensitivity.
Especially useful during
DX
operation.
ATTENUATOR
SWITCH
Used
when
the received
sound from
the speaker
is
distorted
by
very strong
signals.
Push
[ATT]
to the IN position to
activate
the
20
dB
attenuator.
NOISE
BLANKER SWITCH
Reduces
pulse-type noise
such
as
that generated
by
auto-
mobile
ignition
systems.
Note
that
the noise blanker
function does not function
in
-AM
and
FM
modes and
may
not
work
well
when
strong
signals are
on
nearby frequencies or
when
noise
is
con-
tinuous rather
than
pulse-type.