Aaronia SPECTRAN HF-2025, Руководство пользователя

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7.5 VBW (Video filter)
The so-called Video filter is intended for optical smoothing of the signal. The
lower the Video filter setting, the broader and “smoother” the display of the sig-
nal becomes. Using this filter, you can mostly suppress unwanted noisefloors,
harmonics or sporadic peaks. However, with a low
Video filter setting, the dis-
play can become less meaningful. In our example, there might be three sepa-
rate signals present. However, the low video filter straightens these signals out
to become
one single “smooth” signal. The alleged noise band around the sig-
nal has also been “smoothed out”. Thus, when dealing with weak signals, the
Video filter should be used only at a higher setting.
7.6 SpTime (Sampletime)
Sets the time per sample . As a measurement consists of several samples, the
time needed for a complete sweep will thusly increase, too. The higher the
sampletime , the more accurate the measurement, but the longer it will take,
too. Sampletime is measured and set in seconds (from 0.05 to 9.999).
Attention: Please note that special digital communication standards, like
e.g. cell phones, often might not be recognized well or at all with wrong
sampletimes as the “hit rate” will then greatly decrease. Here, you
should always work with the sampletime 0.5 seconds and a small SPAN.
Also note the optimized settings in our free “LCS” PC-Software.
7.7 Reflev (Reference level)
The so-called Reference level sets the position of the signal display relative to
the upper display border. The smaller the setting, the closer you get to the so-
called noise floor and the greater the amount of visible interference. The
Refe-
rence level thus can be used, for example, for optically suppressing distracting,
weak signals. The higher the Reference level , the smaller the amount of weak
signals that get displayed. Only the “peaks” of the strongest signals will be
shown, the rest is “cut off”. Like this, you can, for example, achieve a clearer dis-
play of an interesting, strong signal. Though, for the first measurement, the
Reference level should be set as low as possible to find even the weakest sig-
nals properly.
7.0 The main menu
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VBW =Full VBW =100KHz