Sweep frequency equals test signal frequency
If the pattern is not stationary, the method described is not valid and
cannot be used with accuracy. It is easy to stop a scope waveform display by using
these controls if the frequency of the waveform under investigation is within the
frequency limits of the scope.
Now let's consider a couple of sawtooth sweep frequencies that are lower than
the frequency of the waveform applied to the vertical input terminals.
a. Consider an input sinewave signal with a frequency of 60 Hz, and the
resultant stationary display on the scope showing two complete cycles of the input
In this case the time base
sweep is slow enough to display two cycles of the input wave, each one lasting
1/60th of a second. The sweep time is now a total of 2/60 second (30 Hz)(fig 2-7).
Sweep frequency lower than test signal frequency