Something else I would test for now is variation of step response and bandwidth with signal level as this is a problem with the Rigol DS1000Z series which suffers from overload problems
All 'scopes suffer that if the signal goes wildly offscreen, the DS1054Z is no worse.
Not all oscilloscopes suffer signal distortion from overload; sampling oscilloscopes by the nature of how their sampling works are immune. Some oscilloscopes implement series, shunt, or feedback clamping to reduce or eliminate overload recovery time.
The DS1000Z series suffers from overload problems even for signals which are completely within its dynamic range and this explains the great variations in reported bandwidth but months ago I pointed out other evidence of overload caused by insufficient full power bandwidth.
Or maybe you're referring to abuse of the 'fine' vertical control - switch the vertical response to a range which is too low and crank the fine control to try and bring it back up again. I don't really see that as a problem despite it being used endlessly as a stick to beat Rigols with.
Whatever the detailed cause, better oscilloscopes do not suffer from it. The shape of a signal within the input range should never change with amplitude or position. Good oscilloscope manufacturers figured this out in the 1950s.
Sampling scopes collect a single sample per waveform and dither the time of the sample to form a sweep.
You mean older scopes do this. Modern scopes that can be used also for non-repetitive signals (can be important even for hobbyist to check various buses and transients) just take samples at regular intervals dictated by the sampling rate.
He means *sampling* oscilloscopes which sample before amplification. DSO stands for digital storage oscilloscope which whether modern or old, operates in a completely different way.
It is possible to to use random sampling and avoid aliasing entirely, but that is a *very* different topic called "compressive sensing". So far no one here has taken me up on a discussion of that publicly, though one person has in a PM revealed he understands the topic to some degree.
I am aware of it but do not find it that interesting because HP was the only one to implement it in DSOs that I know of:
https://www.keysight.com/upload/cmc_upload/All/exp66.pdfIt does not avoid aliasing entirely but instead converts the tones produced by aliasing into noise.