Math FFT
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TDS1000/2000-Series Digital Oscilloscope User Manual
Normally, the display compresses the FFT spectrum horizontal ly into
250 points, but you can use the FFT Zoom function to e xpand the
FFT spec trum to more clearly see the frequency components at each
of the 1024 data poi nts in the FFT spectrum.
NOTE. The oscilloscope vertical response rolls off slowly above its
bandwidth (60 MHz, 100 MHz, or 200 MHz, depending on the model,
or 20 MHz when the Bandwidth Limit option is set t o ON). Therefore,
the FFT spectrum can show valid frequency information higher than
the oscilloscope bandwidth. However, the magnitude information
near or above the bandwidth will not be accurate.
Displaying the FFT S pectrum
Push the MATH MENU button to display the Math Menu. Use the
options to select the Source channel, Wi ndow algorithm, and FFT
Zoom factor. You can display only one FFT spectrum at a time.