Rise time measurements counter/timer vs Oscope?

Is the 10/90% on the counter rise time or duty cycle?A sking because the UOM is %, and that's more common for the duty cycle.

2nd check: input impedance of scope vs counter. Are they both 50 Ohm, both high impedance, or is one different from the other?

Ok, yes, It's a time interval parameter, not a duty cycle.

My understanding is the 10-90% is the time interval it takes the signal to go from 10% to it's final value of 90% of it's final value.

It is an adjustable parameter but I thing the 10/90 is most commonly used.

Using 50 ohms input impedance on both.

dc2daylight said:

I thing the 10/90 is most commonly used

Yes, you are correct.

I didn't think counters measured rise-time. At least mine doesn't but then mine isn't the same instrument. It's unusual (or maybe it is a very modern counter?). 

Normally a 'scope is used for this as far as I'm aware - there may be specialized equipment in some industries perhaps, but the general instrument would be the 'scope. And the 'scope should be set to 50 ohm usually, as Jan says (at least most signal generators would expect the load to be 50 ohm).

This one has the rise time functionality. It's a rather advanced (and expensive) instrument.

The 53220A isn't a time-stamping or zero-dead-time counter. So there is a minimum delay needed between start and stop triggers on time interval measurements. The rise time of a fast edge wouldn't satisfy the setup time needed by the counter. 

Is the source clock 50% duty cycle? Perhaps the counter is triggering on the next edge (if the source was 40% duty cycle)

Interesting, nice feature. 

I suppose one other thing to rule in or out, could be, has it ever worked, or is it in some lab and no-one knows if it works. I only say this because people do end up damaging anything RF related, I've seen several destroyed spectrum analyzers, and my counter came destroyed too, fortunately, that was an easy fix. I think people like plugging in transmitters.

If there's another way to verify it works (on all channels if it is a multi-channel instrument, or run diagnostics) could be good to confirm.

Thanks for the response.  I think your on to something there.  I am still finding my way around all the settings on this unit. 

Yes, the duty cycle is set at 50%. Gate and trigger settings have many options including time and delay settings. 

A different path could be to ask the question on EEVBlog: https://www.eevblog.com/forum/testgear/.
There is always someone who has exactly the same instrument as you. It's where the instrument addicts hang out :).