R&S FSH
Spectrum Analyzer Mode
Configuring Spectrum Measurements
Operating Manual 1309.6275.12 - 14
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Enter the reference level you require.
If you change the reference level, the R&S FSH adjusts the position of the trace as
you make the changes.
By default, the reference level corresponds to the grid line at the top of the diagram.
You can also change the position of the reference level to another grid line if you have
a signal that would otherwise overlap with the top of the diagram area. The R&S FSH
indicates the current reference level position with a triangle at the corresponding grid
line on the vertical axis (
).
M
Press the AMPT key.
M
Press the "Range / Ref Pos" softkey.
The R&S FSH opens a submenu.
M
Select the "Ref Position 10…" menu item.
The R&S FSH opens an input field to define the reference position.
M
Enter the number of the grid line you want the reference level at.
The range is from 0 to 10. "0" corresponds to the lowest grid line, "10" corresponds
to highest grid line.
2.2.2.2 Setting a Display Range
The display range determines the scaling or resolution of the vertical axis. In the
default state, the display range is a logarithmic scaling over a 100 dB. This
corresponds to 10 dB per grid division. The R&S FSH provides other display ranges
that either increase or decrease the resolution of the vertical axis.
However, increasing resolution does not increase the accuracy of, for example, the
marker level readout, but only makes it easier to read values off the trace.
You can also select a linear scale for the vertical axis. In that case, the power levels
are expressed as a percentage of the reference level. Linear scaling is useful to
display AM modulated carriers in the time domain, for example.
M
Press the AMPT key.
M
Press the "Range / Ref Pos" softkey.
The R&S FSH opens a submenu to select the display range.
M
Select the display range you need.
The R&S FSH adjusts the vertical axis accordingly.
2.2.2.3 Selecting the Display Unit
By default, the vertical axis (and therefore the reference level) is scaled in dBm.
However, the units dBmV, dB
Y
V, Watt and Volt are also available. Selecting the right
unit is relevant for the marker level display because the unit of the marker level is the
same as that of the reference level.
