User Manual

WiNRADiO G3XX User’s Manual
Scanning
The WiNRADiO G3XX application contains a comprehensive set of scan
functions to enable the user to search for stations which are currently on the
air. There are three basic types of scanning: Immediate Scanning
(Searching), Range Scanning and Memory Scanning. The scanning method
is selected using the appropriate button in the Scanning Control Panel:
Immediate Scanning (Searching)
This is the simplest scanning method. Click on the Search button to select
this scanning mode, then use the [>>] or [<<] buttons to scan either forward or
backward from the currently tuned frequency. To stop scanning, press the
Stop button (marked with a green square). To pause, press the Pause button
(marked with two vertical bars).
If you are using the Signal level type of squelch, then a signal is considered
‘found’ when the signal level becomes higher than the squelch level. If you set
the squelch level too low, scanning will stop even if there is no signal (the
background noise peaks will exceed the squelch level). On the other hand, if
the squelch level is set too high, then a useful signal may be missed because
it will fall short of the squelch level. Correct setting of the squelch value is
therefore essential for scanning. With a bit of trial and error, you will need to
adjust the optimum setting for the squelch level (usually a few dB above the
background noise floor).
With Noise squelch (which is especially recommended for use in FM mode),
the signal will be ‘found’ if the receiver finds a channel where the audio is less
noisy, i.e. when the audio has been quietened by receiving an FM modulated
signal and the noise level has fallen under the preset limit. The optimum
setting varies, depending on the IF bandwidth (the wider the bandwidth, the
higher will be the setting, because the noise on an unoccupied channel will be
also stronger).
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