Tektronix SPECMON3 Manual page 38

Operating Your Instrument
1. Select File > More presets > Application.
2. When the preset's displays and settings have all been recalled and acquisitions are running, adjust the
center frequency and span to capture the signal of interest.
3. Set the Reference Level to place the peak of the signal approximately 0-10 dB down from the top of
the Spectrum graph.
4. If the signal is transient in nature, you might need to set a trigger to capture it. For more information
on triggering in the time and frequency domain, see
When the signal has been captured, the spectrogram shows an overview of frequency and amplitude
changes over time. To see frequency transients in greater detail, use the Frequency vs. Time display.
The Time-Frequency Analysis preset sets the analysis period to 5 ms. The Spectrum Span is 40 MHz. The
RBW automatically selected for this Span is 300 kHz. For a 300 kHz RBW, the amount of data needed for
a single spectrum transform is 7.46 μs. A 5 ms Analysis Length yields 671 individual spectrum transforms,
each one forming one trace for the Spectrogram to display as horizontal colored lines. This preset scales
the Spectrogram time axis (vertical axis) to -2, which means that the Spectrogram has done two levels of
time compression, resulting in one visible line for each four transforms. This results in 167 lines in the
Spectrogram for each acquisition, each covering 29.84 μs.
Creating User Presets
You can add your own presets to the list that appears in the User Presets dialog box. Configure the analyzer
as needed for your application and create a Setup file in C:\SPECMON Files\User Presets. The name you
give the file will be shown in the User Presets list on the Presets tab of the Options control panel. For
instructions on how to save a Setup file, see
Configuring How Presets Are Recalled
Recalling Presets results in either of two actions. One action is to immediately execute a Preset. The
second action displays a list of Presets from which you select the Preset you want to recall. You specify
which action occurs when you recall a preset using the Presets tab on the Options control panel.
Configuring how a preset is recalled.
1. Select File > More presets > Preset options This displays the Presets tab of the Options control panel.
2. Select the Preset type from the drop-down list that you want to configure. For each type listed there
are unique presets that appear in the Presets box.
3. Select the Preset action from the drop-down list.
26
Triggering
Saving Data (see page
To configure how a preset is recalled:
379).
SPECMON3 & SPECMON6 Printable Help
Presets