Internal jitter in DSO4202C oscilloscope

TMG

Hi Sead

What high frequency do you mean?

You can check if probe cable are straight not twisted with others or create coil turns. If you touch by hand cables also you can affect signal that you observe.
If you are able to use probe from Keysigh/HP scope with Hantek? Check if is better or not.

I've checked DSO4254C with TDS 620A and can't see significant differentials. Only when i touch cables or twist them. Test frequency 25 MHz. I don't have that big jitters as you but i don't know what was you signal frequency.