The f9p is about 3 times better than the ublox m8t. Will post a plot later..
Cheers Michael On Tue, 19 Mar 2019 at 9:00 am, Bob kb8tq <[email protected]> wrote: > Hi > > ….. and here I was wondering if it had ever gone out :) Glad it made it. > > No, I did not run any single frequency units beside it. It is much better > than any similar plot > I’ve done in the past on an L1 only part. > > Indeed, as long as you just look at the first ~ 100 seconds, the > “reference standard” is less of an issue. > A fairly typical OCXO will hang in there at 2 ppt or so out to a couple > hundred seconds. > You can get a very good idea of what’s what simply by going out that far. > Indeed you might spend > some “quality time” finding a working example of something like a MT-260. > That’s part of the fun …. > Some of the better parts will be 5 MHz units. A HP 5335 can come in handy > to turn 5 MHz into > 10 MHz ….. there are a lot of ways to get that done. > > Yes LH and a TAPPR TICC would also help in the process …. still need those > 25 orders :) > > Bob > > > On Mar 18, 2019, at 3:29 PM, Dan Kemppainen <[email protected]> > wrote: > > > > Bob, > > > > I recalled the plot you posted a few days ago. Nice plot on the F9P, > BTW. Thanks for posting that. > > > > I don't supposed you happened to be recording a similar plot with a L1 > only Ublox part at the same time by chance, did you? I think it would be > interesting to compare a 6T or M8 part to the F9P. (I lack a standard good > enough to compare them to...) > > > > Thanks! > > Dan > > > > > > > > > > On 3/18/2019 1:00 PM, [email protected] wrote: > >> Message: 2 > >> Date: Mon, 18 Mar 2019 12:26:55 -0400 > >> From: Bob kb8tq<[email protected]> > >> To: Discussion of precise time and frequency measurement > >> <[email protected]> > >> Subject: Re: [time-nuts] Frequency Ensemble > >> Message-ID:<[email protected]> > >> Content-Type: text/plain; charset=utf-8 > >> Hi > >> There are a variety of GPS devices that put out a PPS. uBlox makes > some, there > >> are a number of other companies that do so. The PPS comes out modulo > the local > >> timebase. On a precision part, there is a ?sawtooth correction? message > that also > >> comes out to further quantify the best guess time of that pulse. > >> Noise wise, even with correction you are lucky to get a one second ADEV > in the > >> 1 to 2 ppb range with a typical L1 receiver. With a L1 / L2 device like > the F9P, > >> you might do a bit better than that. > >> The ADEV of your other sources at short tau will be much better than > the GPS PPS > >> noise. As you average out over long periods, the GPS will win the race. > >> Bob > > > > _______________________________________________ > > 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.
