[time-nuts] M12 100 Hz vs. 1PPS measurements

[Ulrich Bangert]

Warren,

if you consider Stanford Research as a producer of a "better GPSDO" you
can download their PRS10 manual from their web pages. It contains all
the math that you are asking for.

Best regards
Ulrich

> -----Ursprungliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von WarrenS
> Gesendet: Samstag, 6. Dezember 2008 16:04
> An: Discussion of precise time and frequency measurement
> Betreff: Re: [time-nuts] M12 100 Hz vs. 1PPS measurements
> 
> 
> 
> Tom, 
> This is great work and Information to see.
> I do think that this will inspire, and make if not a giant 
> leap, at least a small step to better GPSDO performance. 
> 
> 1st question:
> Does anyone have or can they tell me where to get a copy of 
> the actual raw data Tom used for these plots? 
> http://www.leapsecond.com/pages/m12-adev/
> 
> The Link on his leapsecond site to the raw data seems to be 
> missing. www.LeapSecond.com/logs/ - Logbook and raw data (ask) 
> A request to Tom, so far has gone unanswered.
> 
> 2nd question 
> Can anyone provide me with the filter formula or algorithm or 
> any information 
> regarding that is used by any of the better GPSDO units to 
> calculate the ECV 
> Dac output voltage.
> 
> I know about the simple basic 1st order averaging  filter 
> used in some of the units, 
> and the even more basic but effective over under check to 
> increment / decrement 
> an accumulator.  BUT it would seem to me there has got to be 
> filters that give much 
> better result than either of these available and being used out there.
> 
> Allan deviation (ADEV) and Modified Allan deviation (MDEV) 
> http://www.mail-archive.com/time-nuts@febo.com/msg07211.html
> 
> 
> 
> 
> I'm looking for just the basic formula used to process the 
> phase error data before 
> being applied to the DAC. I am not looking for anything 
> secrete or with all the extra 
> things some use to verify that the data is valid or 
> appropriate before being applied 
> or thrown away.
> 
> Thanks, for any information you can provide me.
> WarrenS
> 
> **********************
> 
> 
> ----- Original Message ----- 
> From: "Tom Van Baak" <tvb at LeapSecond.com>
> To: "Discussion of precise time and frequency measurement" 
> <time-nuts at febo.com>
> Sent: Friday, December 05, 2008 12:32 AM
> Subject: [time-nuts] M12 100 Hz vs. 1PPS measurements
> 
> 
> >I know a number of you have been waiting for the results of  
> this M12 
> >experiment. I compared the performance of a 100 Hz  output 
> vs. a 1PPS 
> >output vs. a 1PPS with sawtooth correction.
> > 
> > http://www.leapsecond.com/pages/m12-adev/
> > 
> > I think it came out quite well and it may surprise some of you.
> > 
> > /tvb
> > 
> > 
> > 
> > 
> >
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts
> and 
> follow the instructions there.
>