Hi Ed,
Looks kind of reasonable. Signal level and slow phase-drift can
illustrate some interesting properties which is sometimes hidden.
You have cross-talk and that can interact in interesting ways. You
mention low signal levels, and well, this would be consistent with that.
You should square the signal up using gain, stage. See the Wentzel
approach, as being used at the clock input of the TAPR TADD-2 for instance.
Cheers,
Magnus
On 05/30/2017 04:54 AM, Ed Palmer wrote:
I was comparing my Sulzer 2.5 to my Efratom FRT and saw something very
odd. I don't know if my PM6681 has developed a fault or if I'm just
measuring two oscillators that are good enought to show oddities in my
measurement system.
When the phase of the two signals drifts through zero, the measurement
gets noisy. The levels are very low as you can see in the attached
graph. Without the averaging, you can barely see anything. But the
degradation is significant.
I've checked my counter and can't find anything wrong. Power supplies
are clean. I've worked through the voltage tests and adjustments in the
service manual. Nothing was out of adjustment and nothing improved.
Does this look like a fault or is it just another reason to avoid phase
wraps and the dead zone around zero degrees?
Thanks,
Ed
_______________________________________________
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.
_______________________________________________
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.
