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4
USING DIFFERENT OPERATING MODES
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Convenient functions for receive
q
Preamplifier and attenuator (p. 38)
The preamp amplifies received signals in the front end
circuit to improve the S/N ration and sensitivity. The at-
tenuator prevents a desired signal from distorting
when very strong signals are near the desired fre-
quency or when very strong electric fields, such as
from a broadcasting station, are near you.
w
Noise blanker (p. 39)
The noise blanker is used to reduce pulse-type noise
caused by vehicle ignition systems and key clicks from
strong CW signals on nearby frequencies.
e
Noise reduction (p. 40)
The noise reduction function reduces noise compo-
nents and picks out desired signals which are buried
in noise. This function digitally transposes receive
audio components to produce desired AF frequency
characteristics at the IF stage.
r
Twin PBT (passband tuning) (p. 41)
The PBT function electronically narrows the receiver’s
IF passband widths to reduce interference. Moving
both [TWIN PBT] controls to the same position shifts
the IF.
t
AGC (auto gain control) (p. 39)
The AGC controls receiver gain to produce a constant
audio output level even when the received signal
strength is varied by fading, etc.
y
1/4 function (p. 39)
Normally, one rotation of the tuning dial changes the
frequency by about 5 kHz (in 10 Hz tuning steps).
Using the 1/4 function sets the tuning dial so that one
rotation changes the frequency by about 1.25 kHz (in
10 Hz steps). This is convenient for critical tuning.
DSP
Summary of Contents for IC-746
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