One might also do some trials based on comparing ADEV results between a clean carrier signal and ones corrupted with varying degrees of FM (for example), to get a feel for the problem. If nothing else, one ought to be able to get some feel for the sensitivities involved.
Dana K8YUM On Mon, Aug 6, 2018 at 8:17 AM, jimlux <jim...@earthlink.net> wrote: > On 8/5/18 11:22 PM, Poul-Henning Kamp wrote: > >> -------- >> In message <84a802ff-88f1-5f50-1f79-71d8ba3c4...@rubidium.dyndns.org>, >> Magnus D >> anielson writes: >> >> What does exists is a formula for how a single sine spur would produce >>> ADEV. A FM deviation with low enough modulation index creates two >>> side-bands of opposite sign but same amplitude. >>> >> >> I find the easiest way to wrap my head around this is to think >> about measuring Adev by timing zero-crossings. >> > <snip> > >> Depending on the modulation signal, there may be moments where the >> zero-crossing is "where it should be", for instance if the modulation >> is sine or triangular, but not if it is a signed square wave. >> >> > > > What about doing some sort of fit to the measurement data before > calculating the ADEV? Similar to removing a linear ramp. > > basically you'd solve for the three sine parameters (f, phase, > amp/deviation), then remove that from the data, then run the ADEV > calculation. > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/ > listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.