34
2.
Measure FFT Frequency
1)
Press the CURSOR button.
2)
Press the “Cursor Mode” button to select “Manual”.
3)
Press the “Type” option button to select “Time”.
4)
Press the “Source” option button to select “FFT”.
5)
Press the “Cur1” option button, turn the “Universal” button to move Cursor 1 to
the highest position of the FFT waveform.
6)
The value of Cur1 displaying on the top of the left screen is FFT highest
Frequency. This frequency should be the same as input signal frequency.
Picture 2.6-12
NOTE
：
●
The FFT of a waveform that has a DC component or offset can
cause incorrect FFT waveform magnitude values. To minimize
the DC component, choose AC Coupling on the source
waveform.
●
To display FFT waveforms with a large dynamic range, use the
dBVrms scale. The dBVrms scale displays component
magnitudes using a log scale.
●
The Nyquist frequency is the highest frequency that any real-time
digitizing oscilloscope can acquire without aliasing. This
frequency is half that of the sample rate provided it is within the
analog bandwidth of the oscilloscope. Frequencies above the
Nyquist frequency will be under sampled, which causes aliasing.
Summary of Contents for SDS1000 Series
Page 146: ...138 Coupling DC...
