LeCroy Digital Oscilloscopes, Manual

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Note: Several different types
of FFT results, windows and
sources can be selected from
the “FFT result” menu, shown
here. See Appendix C of the
Operator’s Manual for details.
On this screen, “
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” has been
selected for characterizing
spectra containing isolated
peaks.
FFT information listed in the
box beneath the grid includes:
Nyquist frequency — the
input signal must have
components of a frequency
lower than that of the Nyquist
in order to avoid aliasing;
∆
f — the distance in hertz
between the center
frequencies of two
neighboring FFT bins, where
∆
f =
1
Time / Div 10
×
;
500 pts — the total number of
FFT points.
Then press the to select “FFT” from the “Math
Type” menu.
Now press to turn on TRACE A.
The screen will now display:
7LSV
: To enable any Math function to use more of the
acquired data, press MATH SETUP and set “for Math use
Math points” to the maximum value — 10 million. The
scope will use all of the acquired data. Calculations will be
slower but more accurate. In this example, the FFT is
performed on all 500 points of acquired data.