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decides whether scanning is stopped at the signal or not.
Therefore You should test the various muting settings for various
signal strengths and get to know this function.
ASC Noise and Interference Reduction
While the Squelch opens and closes statically at a certain preadjusted signal
strength value of the incoming signal, not taking into account interference signals,
the ASC circuit works very smooth and dynamically. It measures the signal to noise
ratio and if interference signals suddenly appear, ASC automatically varies the
threshold point to a safer adjustment and returns to the old adjustment when
interferences are disappearing again.
An example:
You have adjusted the SQUELCH carefully to the most sensitive point while the
engine of Your car was still off. Now You start the engine and switch on the
windshield wiper the squelch circuit will immediately regard the interference of the
engine or wiper as a signal and will open, because the squelch cannot distinguish
between a wanted signal and an unwanted interference.
If You would have preset the ASC at switched-off engine before, the interference
coming from the wiper motor would be detected and the ASC circuit would shift the
threshold point so long automatically, until the interference will disappear.
The radio will remain muted, but stay on the highest sensitivity level during the whole
procedure studied in this example.
That means: in most cases You only need to adjust the ASC knob to Your needs only
once before starting. The setting will be maintained during travelling. The switching
point is no sudden on-off point like the squelch, but a more smooth gliding effect
between on and off. The best point is, where the background noise is just becoming
so weak, that it does no more disturb You. A small background noise may remain.
Please do not turn the ASC knob too much into full
clockwise direction. If You intend to suppress weaker
signals, which You do not like to hear, use the inner Squelch
knob for this purpose and not the ASC knob. A symptom for
too much closed ASC potentiometer is when weak speech still
comes through, but louder speech no more.
AM / FM mode switch
In the two programming modes 40/40 and 80 channels, FM modulation is available
on all channels, but AM-transmitting only on the 40 international CB channels. On all
channels you can switch between AM and FM using the function button AM/FM. The
display shows either AM or FM accordingly.
When You switch on the set the first time it operates on FM.
Please note that in 80 ch mode, on channels 41-80 the operation is limited on AM. To
receive AM-modulated signals on channels 41 to 80 is possible, but the AM-
transmitter is disabled for these frequencies. If Your radio is set to AM and You push
the PTT-button, the radio will show Er (error).
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