R&S FSH
Spectrum Analyzer Mode
Performing Spectrum Measurements
Operating Manual 1309.6275.12 - 14
74
M
Position the time line by entering a number or moving it with the rotary knob.
Entering 0 sets the time line marker on the most recent frame. The maximum value
that you can enter is 1024 (the maximum number of frames the R&S FSH can
store in its memory).
Note that not all frames are visible on the screen. If a frame is part of the history
outside the visible area, the time line is also not visible and you have to scroll
through the spectrogram to be able to see it again.
The upper window will display the spectrum of the frame at the time line position. By
moving the time line you can thus browse through the history of spectra stored in
memory.
In the marker information field, the R&S FSH shows the time stamp of the time line.
The time stamp of the first time line T1
is always referred to the top-most
frame (e.g. a time stamp of
00:00:50:000 means that the data was
measured 50 seconds prior to the top-
most frame).
M
Press the "Select Time Line"
softkey again.
The R&S FSH opens an input field
to define the position of the
second time line (T2).
M
Enter a number with the number keys, the rotary knob or the cursor keys.
The R&S FSH positions the second time line on the selected frame. Again it shows
the time stamp of the time line in the marker information field (
U
T value). For the
second time line (T2), the information is relative to the first one (T1). This means
that the time stamp of the second time line can be negative, if you have set it on a
frame above the first time line.
If you scroll the time line through the frames of the spectrogram with the rotary knob or
the cursor keys, the R&S FSH will show the spectrum corresponding to the selected
frame in the upper window of the display.
You can use the spectrogram playback for a detailed analysis of the signal levels over
time and compare signal details in the spectrum result display, e.g. with the help of
markers.
In addition to the time line (horizontal marker), you can also use (vertical) markers in
the spectrogram.
With the help of the marker and the time line, you are able to find the exact moment
when a specific event has occurred in the spectrum.
