User Manual

WiNRADiO G3XX VHF/UHF Receiver
To set up spectrum sweeping, enter the Start and End frequencies to specify
the start and end of the sweeping range, respectively. Alternatively, you may
enter the Center and Span frequencies.
Next select the RBW (Resolution Bandwidth), which determines how detailed
the spectrum will be (the lower the RBW, the finer the detail). The finest RBW
is 15.625 Hz. The RBW has a proportional effect on the spectrum sweeping
speed, i.e. the greater the RBW, the faster speed, but at the expense of detail.
The VBW (Video Bandwidth) is a low-pass filter which is applied to the
resulting “video” trace of the signal and makes it possible to smooth the trace.
The lower the VBW, the smoother the trace. This setting has the same effect
as the Video Filter in the demodulator panel.
The spectrum analyzer, when activated, disables the AGC. This is in order to
have a uniform gain for the entire scanning range – if the gain was changing
due to the AGC action, the spectrum trace would be distorted (stronger signals
would appear weaker, and weaker signals would appear stronger). The Gain
control (adjustable from 0 to 99 dB) is used to set the IF gain for the spectrum
analyzer.
Note that if the gain is set too high, the receiver may overload in the presence
of strong signals and the trace will be distorted around these signals. On the
other hand, if the gain is too low, some weak signal peaks may be missed.
The sweeping is controlled using a set of buttons similar to an audio recorder:
The Start button (with a triangle) starts sweeping. The Stop button (with a
square) stops sweeping, while the Pause button (with two vertical lines)
pauses it:
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