On Fri, 2009-01-09 at 10:28 +1300, Bruce Griffiths wrote: > Richard Moore wrote: > > On Jan 8, 2009, at 2:58 AM, time-nuts-requ...@febo.com wrote: > > > > > >> Message: 6 > >> Date: Thu, 08 Jan 2009 11:51:50 +0100 > >> From: Magnus Danielson <mag...@rubidium.dyndns.org> > >> Subject: Re: [time-nuts] GPSDO time constant > >> To: Tom Van Baak <t...@leapsecond.com>, Discussion of precise time and > >> frequency measurement <time-nuts@febo.com> > >> > >> For ThunderBolt owners it is pretty straightforward to adjust the > >> TC and > >> damping, which is very nice. Use this oppertunity! > >> > > > > So, Magnus (and Tom), what damping factor do you suggest for a TBolt? > > I'm running a verrry long TC now. If 1.2 is not actually critically > > damped, what value would be? Any guesses? BTW, I really like that > > plot of Tom's that tracks the oven and then gets better from the GPS... > > > > Dick Moore > > > > > Richard > > As always, the problem is how do you know that the time constant you are > using is anywhere near optimum? > > > Bruce
So what is optimum... from control theory we learn, that with an even better model of your system, you can push performance to the edge! But you always loose robustness in doing that. So what is the implication of a to large TC here? Nothing going instable in the control loop? We are just following the "freerunning" OCXO curve past the point where GPS goes downhill? -- Björn _______________________________________________ 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.