On 2012-05-24, Dave Hart <[email protected]> wrote: > On Thu, May 24, 2012 at 4:24 PM, Chris Albertson ><[email protected]> wrote: >> Lots of good discussion here but I found an easy way to stay "on-time" >> while the Internet is down and GPS is not available. ?There are some >> people on eBay selling Rubinium oscillators for about $40. ?They have >> a pulse per second output. ? ?These Rb clocks will keep NTP within >> reasonable specs for a LONG time. ?It does required some effort to set >> up. ?Just wanted to point out one more option. > > ntpd requires reference clocks provide time, not just frequency. How > do you discipline the Rb PPS to occur at the top of the UTC second (or > a fixed offset from the top)?
Well, you could measure it while your ntp is up, and then use it as a flywheel while other sources are down. Ie, run the rubidium, examine the offset of the rubidium on a well controlled clock (eg by GPS) and then run the rubidium as a source with a known offset. > > Cheers, > Dave Hart _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
