Newbie Scope: Things that aren't square...

[tooki]

Someone in a related topic gave an advice of switching your probes to x10 and wrapping the switches over with insulation tape to make them stay in that position, and that's a good advice.
I would only add that it's better to use a heat shrink tube for this: it looks better and does not leave a sticky residue.

Yep. Or just replace them with fixed x10 probes! (For example, the basic x10 probes from Testec only cost about €15 and are way nicer than Rigol’s probes.)

[PA0PBZ]

It's a rainy Saturday here so I created your circuit and measured twice: 500MHz bandwidth and 20MHz bandwidth, see pictures and note the difference.
I didn't have (didn't want to search too long) a 18MHz crystal so I used a 16MHz one, shouldn't matter.

500MHz:



20MHz:

[NivagSwerdna]

Very nice.

Comparing those with my pictures from post#17...


https://www.rigol-uk.co.uk/product/rigol-ds1052e-50mhz-digital-oscilloscope/

So my scope is allegedly

50MHz

and it was 'tweaked' with some firmware hack to be '100MHz'...

I would have thought my pictures would look better?

[tggzzz]

If you can see  a 3.5ns risetime, then it is 100MHz.

If you can see a 7ns risetime, then either it is 50MHz or you are seeing the signal's risetime.

[ebastler]

Someone in a related topic gave an advice of switching your probes to x10 and wrapping the switches over with insulation tape to make them stay in that position, and that's a good advice.
I would only add that it's better to use a heat shrink tube for this: it looks better and does not leave a sticky residue.

Yet another way to implement this: On many low-cost probes (including the ones from Rigol which I have), you can simply pop out the little "grip" piece of the slide switch. That leaves you with a nicely recessed switch which can still be moved to 1x with a small screwdriver in the rare situations where you need that -- but otherwise can't be moved inadvertently.

[IDEngineer]

I suspect you have a (probe) connection issue at work too. I believe I can see your top, yellow trace riding on what looks to be a sine-ish lower frequency. I'd double check your physical connections. Can't accurately diagnose a signal until you're sure it's ONLY that signal you're looking at!