Ulrich Thanks, I'd forgot about that, I'll certainly check it out better this time. The PSR10 being a Rb and not a OCXO, I would expect the best type of tracking filter used there to be somewhat different, and I mean in more ways than just a longer time constant. Last I looked, I thought that I saw was that they just set their simple filter to about 20 hrs.
WarrenS ************** ----- Original Message ----- From: "Ulrich Bangert" <[EMAIL PROTECTED]> To: "'Discussion of precise time and frequency measurement'" <[email protected]> Sent: Saturday, December 06, 2008 9:06 AM Subject: Re: [time-nuts] M12 100 Hz vs. 1PPS measurements > 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: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] 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/[email protected]/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" <[EMAIL PROTECTED]> >> To: "Discussion of precise time and frequency measurement" >> <[email protected]> >> 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 -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts >> and >> follow the instructions there. >> > > > > _______________________________________________ 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.
