Icom IC-751A - Page 15

©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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