Hi Scott, The 20 bits span about 6 volts. The EFC range spans about 8Hz (+/-4Hz). I don't do these calculations every day, but that's about 4.5PPT? Bob ----------------------------------------------------------------- AE6RV.com
GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Scott Stobbe <scott.j.sto...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Saturday, November 5, 2016 8:38 PM Subject: Re: [time-nuts] Thermal impact on OCXO I think that's a nice plot, it looks like you have stepped 160 LSB over 7 days or roughly 1 LSB per hour. With a 20bit dac you are trimming maybe 1 ppt/LSB to 4 ppt/LSB? In allan devation terms, the case of 1ppt/LSB, solely due to drift, you're at 1E-12 at 3600*sqrt(2) = 5000 s, in the case of 4ppt/hour your at 1E-12 at 1280 s. Seems reasonable. On Sat, Nov 5, 2016 at 2:47 PM, Bob Stewart <b...@evoria.net> wrote: Oh dear. I attached the wrong file. Here's the correct one. ----------------------------- ------------------------------ ------ AE6RV.com 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.