R&S FSH
Spectrum Analyzer Mode
Configuring Spectrum Measurements
Operating Manual 1309.6275.12 - 14
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2.2.1.2 Defining a Frequency Step Size
If you set the center frequency with the rotary knob or the cursor keys, the distance of
each step that you take depends on the span. With the rotary knob, the smallest
possible step is a pixel. As the trace consists of 631 pixels, each step is equal to 1/630
of the span. With the cursor keys, the step is 10% of the span or one division of the
grid.
You can set another step size.
M
Press the FREQ key.
M
Press the "CF Step Size" softkey.
The R&S FSH opens a submenu that contains possible step sizes.
-
0.1 x Span
The step size equals 10% of the span or 1 division of the horizontal axis.
-
=Center
The step size equals the center frequency.
This step size is ideal for measurements on harmonics. When you increase or
decrease the center frequency, the center frequency automatically moves to
the next harmonic.
-
Manual…
Define any step size you want.
This step size makes it easy to investigate a spectrum with frequencies at
constant intervals.
M
Select the step size you need from the menu.
The R&S FSH adjusts the step size accordingly.
If you set the step size to 10% of the span or to the center frequency, the R&S FSH
sets the step size internally. Manually defining the step size opens an input field to
define the step size.
2.2.1.3 Setting a Frequency Offset
For measurements on frequency converters such as satellite downconverters, it is
often convenient to reference the results to the frequency prior to conversion. For this
purpose, the R&S FSH offers a frequency offset that arithmetically shifts the center
frequency to higher or lower frequencies. Thus, the R&S FSH displays the input
frequency of the DUT.
Positive frequency offset is possible in the range from 1 Hz to 100 GHz, in steps of
1 Hz. The maximum negative frequency offset depends on the start frequency you
have set. The start frequency, taking into account the frequency offset, is always
X
0 Hz.
