What is the effect of aliasing on a digital oscilloscope when displaying a waveform?
Why A digital scope samples the input at discrete intervals; the Nyquist criterion requires the sample rate to be more than twice the highest frequency component present. If the signal exceeds that limit, the samples reconstruct a completely different, much lower frequency waveform that appears to wander or jitter on the screen. That ghost trace is aliasing, and it can look convincingly like a real signal if you do not check the timebase and sample rate.
Watch out Vertical accuracy, DC offset and blanking are all amplitude or display issues; aliasing is purely a time-axis sampling artifact and leaves the vertical calibration untouched.
Aliasing = undersampling. Too few samples makes a fast signal masquerade as a slow, jittery one (like wagon wheels in movies).