So far, I’ve been configuring my 53220A for frequency measurements with a 500 msec gate time, and using the external reference and one input.
If instead I send the two devices into inputs A and B, and ask for the time interval between the two and give that to Timelab, my results look quite a bit worse. At the moment, I’m doing that with a pair of 5680As. The ADEV at 100s is reasonably close to the spec at 1.83E-12, but the tau at 10s is what it’s *supposed* to be at 1s: 1.43E-11. At 1s, it’s 1.42E-10. The line is quite linear between those points, but the slope is way off the spec. The frequency difference graph supports this view - it shows a ±2E-10 “haze.” I don’t have any reason to believe either oscillator is misbehaving to an extent that would explain this. I’m fairly sure I’m making some kind of fundamental newbie mistake and the test setup is introducing some sort of error, or I’m inside of the uncertainty of the 53220A and that’s why it’s showing poorly at low tau. My money is on the former. :) The behavior I see suggests that how Timelab works with the 53220A is that it sends a command to obtain a single measurement over and over again. Thus, the network latency figures into the measurement timespan, I think. I’m sure there’s a way to record measurements in the 53220A internally and then export that file into Timelab, but I haven’t figured that out yet. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
