Hi Typo…
Sorry Bob On Nov 30, 2012, at 9:49 PM, Bob Camp <[email protected]> wrote: > Hi > > A few more possibilities: > > 1) Slip the clock by one cycle per second rather than 10 at once. > 2) Take the pps off of a 100 MHz source sync'd to the 10 MHz and slip by less > than 100 ns per step > 3) Take the pps off of a DDS and fine tune the slip however slowly you might > wish. > > In practice, the approach is "get back to +/- 100 ns as soon as you can". The > system majority of specs care about being at the right time, and not so much > how you get there. There are a few specs that prefer a frequency slew to > bring the pps in from microseconds of error, but not many. > That should have been milliseconds of error. A microsecond is a ppm off for a second, that you commonly see corrected with a frequency slew. > Bob > > On Nov 30, 2012, at 9:10 PM, Hal Murray <[email protected]> wrote: > >> >> Does anybody know what happens in a TBolt or Z3801? (or any other boxes?) >> >> >> Suppose your system goes into holdover for long enough to be interesting. >> Suppose for discussion that the clock drifts so that the PPS if off by a >> mircosecond. >> >> I can see two ways to recover. One is to jump the 10 MHz clock by 10 >> cycles. >> The other is to adjust the frequency so that the PPS slews back to on-time. >> >> The first approach gives you a second with the wrong number of cycles. The >> second approach has your clock frequency off for a while with a trade off >> between how far off and how long it's off. >> >> Are there any other approaches? >> >> >> -- >> These are my opinions. I hate spam. >> >> >> >> >> _______________________________________________ >> 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. _______________________________________________ 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.
