Icom IC-751A Instruction Manual page 15

@MULTIFUNCTION METER
@NOISE BLANKER TIMING SWITCH
[NB WIDE]
vox
COMP
NB WIDE
ICJI
ICJI ICJI
GAIN-VOX-DELAY . NB LEVEL
o,b O 0
KEY SPEED FULL · . OFF
@SPEECH COMPRESSOR SWITCH
[COMP] .
•SEMI BREAK-IN,
FULL BREAK-IN OPERATION
®)vox
GAIN CONTROL
GAIN-VOX-DELAY
lncreases
@ @
keying speed.
O F ~
~
Longer delay.
KEY SPEED FULL
®vox
DELAY CONTROL
(VOX time constant)
@)NOISE BLANKER LEVEL CONTROL
[NB LEVEL]
NB WIDE
ICJI
NB LEVEL
0
OFF
ln the receive mode, the IC-751 A front panel meter acts as an
S-meter (signal strength meter). ln the transmit mode, the meter
has six different functions as stated in ltem@METER SWITCH.
The blanking time of the noise blanker circuit may be set for
NORMAL or WIDE with this switch. Use this switch in conjuncti.9n
with the NOISE BLANKER LEVEL CONTROL described in Item
®·
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.
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. ln CW, semi break-in or full break-in opera-
tion is possible.
Semi break-in operation refers to automatic switching of the
transceiver. betweeri 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.
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 contrai so
the VOX circuit activates with a normal speech level.
• When operating in the CW mode, this contrai turns the electranic
keyer unit ON and OFF, plus varies the speed (5-45 wpm) of the
unit. When the contrai is OFF, manual CW operation is possible.
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.
This contrai varies th'e threshold level of the noise blanker. Adjust
to remove the noise without adding distortion to the received signal.
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