HP 54750A, Руководство пользователя, Страница: 279 / 478

General Purpose Oscilloscope Menus
FFT Menu
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Y-Scale
The Y-Scale function uses software expansion to set the vertical scaling of
the FFT function. It does not aect the hardware settings in the plug-ins .
The scaling units are in dB per division. F or example , if the scale is set to
10 dB/div , and a peak is two divisions high, you know that the amplitude of
the frequency peak is 20 dB .
K ey Path 4
FFT
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FFT Scaling
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Y-Scale
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Y-Offset
The Y-Oset function uses software expansion to move the FFT function
vertically on the screen. Oset is the value at the center of the graticule
area. If you adjust the oset so that a peak is at the vertical center of the
graticule area, then you know that the peak magnitude is the oset value . F or
example , if the peak of the spike is at the vertical center of the graticule area
and the oset reading is 016.2 dBm, then you know that the peak magnitude
is 016.2 dBm.
K ey Path 4 FFT 5
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Display On
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FFT Scaling
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Y-Offset
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