> Here are the results I got using your suggestion. The numbers may be a bit > different than last night as I'm not sure I'm using the same cable.
> A+, B+ = 18.9 ns > A-, B- = 19.4 ns > Obviously there is some difference in delay between the A and B channels. > Otherwise, the two numbers would have been identical - correct? ... > If I take the average of the two readings, I get 19.05 ns, which is more > precise than the readings I'm taking. I'm rounding to the nearest 0.1 ns on > the readings. There are several possibilities for asymmetry. The input signal could have other than a 50/50 high/low ratio. The trigger levels could be set at other than the half-way point. Do you have a scope? There are probably second order problems with different rise/fall times. > A+, B- = 5014.6 ns > A-, B+ = 5023.5 ns > If I take the average of these two readings and subtract out the 5 us for > 1/2 period of the 100 KHz square wave, if get 19.15 ns. This agrees > very closely with the above average. I read that as everything mostly works. The question is how well does it work and/or what can you do to get more/better data? You can get another set of numbers by swapping the A and B inputs so the signal goes from B to A rather than A to B. Some of the errors might be more obvious if you deliberately offset the trigger levels. NB: That's for all 4 modes: A+ to B+ will be slightly less than a whole cycle. A+ to B- will be slightly less than a 1/2 cycle. ... -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
