R&S FSH
Spectrum Analyzer Mode
Configuring Spectrum Measurements
Operating Manual 1309.6275.12 - 14
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Press the FREQ key.
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Press the "Freq Offset" softkey.
The R&S FSH opens an input field to set the frequency offset.
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Enter the frequency offset you need.
The R&S FSH adds the frequency offset to the center frequency you have set. A
red dot at the center frequency display indicates that a frequency offset has been
set.
2.2.1.4 Defining a Start and Stop Frequency
Defining a start an stop frequency is best suited for example for measurements on
harmonics or signals whose exact frequency is unknown.
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Press the FREQ key.
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Press the "Start Freq" softkey.
The R&S FSH opens an input field to define the start frequency.
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Enter the start frequency you need.
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Set a stop frequency with the "Stop Freq" softkey.
The R&S FSH adjusts the horizontal axis according to your input, beginning with
the start frequency and ending with the stop frequency.
If you have entered a stop frequency that is outside the maximum frequency range,
the R&S FSH sets the stop frequency to the possible maximum.
The label of the horizontal axis changes from "Center" and "Span" to "Start" and
"Stop".
2.2.1.5 Setting the Span
The span is the frequency range around the center frequency that a spectrum analyzer
displays on the screen. The span you should select depends on the signal and the
measurement that you are performing. A rule of thumb is that it should be at least twice
the bandwidth occupied by the signal.
The span for frequency domain measurements for the R&S FSH4 is between 100 Hz
and 3.6 GHz and for the R&S FSH8 between 100 Hz and 8 GHz.
If you set a span of 0 Hz (zero span), the R&S FSH performs measurements in the
time domain.
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Press the SPAN key.
When you press the SPAN key, the R&S FSH automatically opens an input field to
define the span. If the input field is inactive, you can open it with the "Manual
Span" softkey.
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Enter the span you need.
The R&S FSH adjusts the span of the horizontal axis.
