Before compensating, the probes had a slight up-tick/down-tick when changing edge:
https://i.imgur.com/Db9URoS.jpg
That is now gone, so I must have done something right:
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So I finally got around to compensate each probe (in their colour-coded connector, just in case that matters). Also auto-calibrated the scope; very straight-forward.
Before/after compensating:
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Re: Vevor SDS1104 4 channel scope
would your mains power be at 60Hz ?
richard Today, 12:07hint 16.667mS
the A B debounce looks very uneven between rising and falling edges. the unequal phase shifts so introduced will make R.E data interpretation...