Rohde & Schwarz FSH4, Руководство по эксплуатации

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R&S FSH Spectrum Analyzer Mode
Performing Spectrum Measurements
Operating Manual 1309.6275.12 - 14 71
M Press the "Spectrogram Settings" softkey.
M Select the "Spectrogram Reference Level" menu item.
The R&S FSH opens an input field to enter the spectrogram reference level.
The reference level should be near the maximum level that has been measured
while the spectrogram was running. In the example, the reference level should be
at about -60 dBm.
M Enter the reference level you need.
The R&S FSH now shifts the reference level of the spectrogram to the value you
have entered.
Note that the spectrogram reference level does not affect the spectrum result
display, as well as the spectrum reference level ("Amplitude" menu) does not affect
the spectrogram. In the screenshot the spectrum trace is therefore exactly the
same as in the previous picture.
The result however, still does not
show signal differences in detail.
The only thing that happened is
that the colors have shifted, in the
example to yellow, because the
color that corresponds to the
reference level has shifted from
green to yellow. All other colors
that are part of the color scheme
are still unused, because the
spectrogram level range is still the
same (150 dB).
M Press the "Spectrogram Settings" softkey.
M Select the "Spectrogram Level Range" menu item.
The R&S FSH opens an input field to enter the spectrogram level range.
In the example, the level range of the signal is from about -60 dBm to about
-100 dBm.
M Therefore set the level range to
40 dB to get the whole signal.
As the level range is now adjusted,
the R&S FSH is able to map its
complete color range to the level
range of the signal.
This means that signal parts with a
low amplitude are in a shade of
green while signal parts with a
high amplitude are yellow.