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©MULTIFUNCTION METER
In
the
receive
mode,
the
IC-751A
front panel
meter
acts as
an
S-meter
(signal
strength meter).
In
the transmit
mode,
the
meter
has
six
different
functions
as
stated
in
Item
(3)
METER
SWITCH.
©NOISE
BLANKER
TIMING SWITCH
[NB WIDE]
The
blanking
time
of the noise blanker
circuit
may
be
set
for
NORMAL
or
WIDE
with
this
switch.
Use
this
switch
in
conjunction
with
the
NOISE
BLANKER
LEVEL
CONTROL
described
in
Item
©SPEECH
COMPRESSOR
SWITCH
[COMP]
.
This switch turns the
RF
speech
compressor
circuit
ON
and
OFF.
The
circuit
provides
greater talk
power by
improving the
intelligi-
bility
of the transmitted
signal
over long
distances.
©VOX
SWITCH
This switch turns the
VOX
circuit
ON
and
OFF.
The
automatic
T/R
switching
VOX
circuit
functions
in
the
PHONE
and
CW
modes
when
the switch
is
IN.
In
CW,
semi
break-in or
full
break-in opera-
tion
is
possible.
•
SEMI BREAK-IN,
FULL
BREAK-IN
OPERATION
Semi
break-in
operation
refers
to
automatic
switching of the
transceiver
between
the transmit
and
receive
modes
in
unison
with the
operator's
speech or the
closing
and opening
of the
CW
telegraph key.
Full
break-in operation, usable
only with
CW,
is
the
same
except
the
transceiver
switches even
more
rapidly
after
each element of
an
individual
letter
is
sent.
Full
break-in
operation
closely
simulates
full
duplex communication.
©VOX
GAIN
CONTROL
GAIN—
vox—
DELAY
Increases
keying speed
KEY SPEED
This control
increases
and
decreases the
sensitivity
of the
VOX
circuit.
When
operating
in
the
CW
mode,
iambic keyer operation
is
possible.
•
When
operating
in
the
SSB,
AM
or
FM
mode,
adjust the control so
the
VOX
circuit activates
with
a
normal speech
level.
•
When
operating
in
the
CW
mode,
this
control turns the electronic
keyer
unit
ON
and
OFF,
plus
varies
the speed (5-45
wpm)
of the
unit.
When
the control
is
OFF,
manual
CW
operation
is
possible.
©VOX
DELAY CONTROL
(VOX
time
constant)
This control
changes
the transmit to
receive
switching time. Adjust
it
so transmit to receive switching occurs
during pauses
in
your
speech or
CW
transmission.
©NOISE BLANKER
LEVEL
CONTROL
[NB
LEVEL]
NB
WIDE
NB
LEVEL
OFF
This control
varies
the threshold
level
of the noise blanker.
Adjust
to
remove
the noise
without adding
distortion to
the received
signal.
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