ADInstruments S7200 Operation Manual page 244

AD INSTRUMENTS S7200 TV Signal Analyzer Operation Manual
Control and spectrum calculation mode
The S7200 offers two spectrum calculation modes, FFT and DFT. The DFT is the
foundation of FFT, and the FFT is the fast algorithm of DFT. Every result calculated
with DFT represents a pixel point of the spectrum trace, while every result
calculated with FFT represents a segment of the spectrum trace. If a faster sweep
speed is required, the FFT mode is better suited for the task. In the digital
persistence mode introduced later, only the FFT mode can be used.
Spectrum hold mode
While in the spectrum analysis mode, tapping the soft button [BW/SWP] will
expose the Hold button. When the hold button is tapped, the spectrum trace will
be frozen on the screen, and the softkey button will highlight. Press the button
again to restart the live trace, the softkey button will turn back to normal status.
Figure 6-132 Auto Sweep Time
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