Hi There are a number of GPS errors that turn into “long period” disturbances. A normal OCXO (even a good one) runs with a fast enough loop that they do appear in the output of the GPSDO. One (of many) sources of this sort of error is the 12/24 hour cyclical nature of GPS orbits. Another is the 24 hour cycle the ionosphere goes through …..
Bob > On Oct 25, 2019, at 2:09 AM, Adam Kumiszcza <[email protected]> wrote: > > Hi! > > Thanks for all the responses. As I wrote, the chip can use only 1 > constellation, and I'm not sure it can use Galileo at all, so I'm sticking > to GPS only. As I understand it, GPS errors here smooth out anyway while > disciplining internal OCXO, so it's not so important to have the best chip > available. I guess u-blox zed-f9t with a bad ocxo would be worse than > normal u-blox 7 with a better ocxo? I intend to run it 24h/day BTW. > > As for FreeBSD, I like this system a lot, too. Especially for proper native > ZFS support. I use it mainly for NAS now, but experimented with different > versions before, so I guess I'll go this route. Does Lady Heather compile > on FreeBSD? And is it possible to run it together with NTP for the same > rs232 port? I found this: > https://www.febo.com/pipermail/time-nuts/2010-February/044476.html – but > it's for thunderbolt and at "very early, rough stage". I would like to > attach a small monitor and have LH run there constantly. > > BTW, Fiorenzo Cattaneo, I did not get the picture of your set with > pcengines box. Probably got cut by mailing list. > > Best regards, > Adam Kumiszcza > > On Fri, Oct 25, 2019 at 2:01 AM Charles Steinmetz <[email protected]> > wrote: > >> Bob wrote: >> >>> The “ideal” solution (at least to me) would be a setup that let you >> estimate the time based >>> on each system independently. Even things like survey locations vary a >> bit system to system. >>> Give each one the “fix” that it thinks is best and go from there. Then >> report the output PPS time >>> offset for each of them. Let “higher authority” decide what to make of >> the results. >> >> Well, heck, if you can count on divine guidance, what do you need the >> GPSDOs for? ;-) >> >> Best regards, >> >> Charles >> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
