Thanks Bob and Attila, This problem with the Cs kind of brought the whole question of noise and what ADEVs mean into focus for me. Like most newbies, I had read about the ever increasing stability of time standards and wondered how they could actually know that they were better. I've seen the term 3-cornered hat bandied about, but I didn't really grock it until now. Bob ----------------------------------------------------------------------------------- GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info
From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, June 30, 2016 4:27 PM Subject: Re: [time-nuts] The Nature of Noise Hi If you are measuring noise, then C is the bad one in the group. If you are measuring something else, then it is possible that you are getting bad information. This is a classic argument about comparing devices from the same lot of parts. They might both have a very similar warmup curve or temperature or pressure coefficient. Bob > On Jun 30, 2016, at 2:30 PM, Bob Stewart <b...@evoria.net> wrote: > > With my recent Cs problems, I've been wondering about the subject of noise > generation and measurement. Specifically, my question is this: Let's say > that I have 3 disciplined oscillators: A, B, and C. So, I use the same 5370 > to create a 1000 second ADEV and discover that the 1s noise value between A > and B is low, while the 1s noise between A and C, as well as B and C is high. > Can I then say that both A and B are low noise devices? Or is it possible > that even though I'm measuring 1000 points, both A and B are high noise > devices, but somehow are noisy in the same exact way, and it's actually C > that's the low noise oscillator? > > Bob - AE6RV > ----------------------------------------------------------------------------------- > GFS GPSDO list: > groups.yahoo.com/neo/groups/GFS-GPSDOs/info > _______________________________________________ > 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. _______________________________________________ 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.