Björn Gabrielsson wrote: > On Fri, 2009-01-09 at 10:28 +1300, Bruce Griffiths wrote: > >> Richard Moore wrote: >> >>> On Jan 8, 2009, at 2:58 AM, [email protected] wrote: >>> >>> >>> >>>> Message: 6 >>>> Date: Thu, 08 Jan 2009 11:51:50 +0100 >>>> From: Magnus Danielson <[email protected]> >>>> Subject: Re: [time-nuts] GPSDO time constant >>>> To: Tom Van Baak <[email protected]>, Discussion of precise time and >>>> frequency measurement <[email protected]> >>>> >>>> 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 > > >
Björn My point was that measurements are required to establish the optimum for each individual OCXO not just for a given OCXO model. Bruce _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
