When your measurement reference is not at least a couple of orders of magnitude better than the device you're trying to test, it's difficult to tease out how much of the result is the responsibility of each device. Fortunately, there's a way you can try to tease this out... by adding a third device.

With three devices, you make a triangle of three test runs with each combination of two devices. You then ask TimeLab to give the n cornered hat plot.

With the n cornered hat, TimeLab will attempt to isolate the ADEV of each device given the performance impact it had on the other two.

It's imperfect, of course, because the runs won't be simultaneous, but if you're trying to measure things that are in the 10^-12 neighborhood and you don't have a Cesium reference, it's the best you can do.

OH is an OH300 based GPSDO, FE is an FE-5660A with a GPS discipline board and TB is a Thunderbolt GPSDO.

The samples aren't terribly long, so the right side should be taken with a healthy grain of salt, but really the interesting portions are up to around 10^2. The thunderbolt shows an ADEV somewhat better than expected results, but that's probably (at least somewhat) because I've lengthened the PLL time constant on mine to 3x10^2.

The short tau results for the FE are consistent with manufacturer expectations. The OH300 results are consistent with previous results and are better than the manufacturer's spec at 10^0 (there isn't much guidance other than that).

It does sort of confirm the results I've gotten all along - up to around 5 seconds, the OH300 is more stable, but past that, the Rubidium oscillators are better.