HP 54540 Series - Page 177

Math/FFT Menu
FFT Softkeys
Peak Search Softkey
You can use the peak search softkey to measure the amplitude and
frequency of peaks on the display generated by the FFT function. To qualify
as a peak, the amplitude of the peak must be at least one display division,
chalf a division in the splitscreen mode), and the peak must also be greater
than the search level specified.
The peak search softkey also turns on the markers. The markers are set to
the selected peaks in the peak search field. Markers xl and y1 are set on the
first peak specified, and markers x2 and y2 are set on the second peak
specified. You can select peak numbers from 1 to 99.
To remove the markers from the display.
Press the Shift key. Then, pressthe Clr meas key.
A peak search for both peaks is performed every time the peak search
softkey is pressed. If a peak is not found, a message is displayed, the vertical
marker is set to the right side of the waveform area, and the horizontal
marker is set to the bottom of the waveform area.
For maximum frequency accuracy when using peak search, turn on the FFT
horizontal magnify function, and use both the center freqand# of
points softkeys to isolate the peak of interest.
Search Level Softkey
The search level softkey sets the minimum search level for the peak
search.
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