Hi If you go back in the list archives, there is a lot of info on doing this and that with the F9P and the F9T. For a while, there was speculation that the price on them would come down quite a bit. So far that does not seem to be happening.
Bottom line is that both the F9P and F9T have roughly a +/- 4 ns sawtooth range. The sawtooth error correction information out of the device will take this down a bit, but not quite as far as some of us hoped. Since both devices are dual band, you can easily post process the data against various services. I put out some plots suggesting a pretty good level of performance doing this. (sub nanosecond at short tau). I have not revisited the project since then. As far as either device tagging an input to better than 4 ns …not so much. Same thing with the PPS doing better than that. At the moment, the Furuno modules have the smallest sawtooth window that I know of. Bob > On Jan 6, 2020, at 8:56 PM, Tim S <tim.strom...@gmail.com> wrote: > > Hi, first time poster, just getting into the time rabbit-hole. > > I'm looking at building my own 10MHz double-oven + Rubidium standard > for home-lab use, and I wanted to investigate GPS disciplining. I read > some remarkable work using Jupiter engines and a simple N/1000 and PLL, but > with those receivers becoming much more outdated and higher precision GPS > receivers now fairly cheap - I thought I'd try something new from uBlox to > not repeat prior efforts. I've gone all through every resource I can find > online and on the uBlox forums, but there is a general lack of public > information about the time and clock features of the u-Blox F9 engine. > > Suffice it to say, there is a section in the integration manual where > they elude the 1PPS signal is set to the closest one of 1023 edges - which > seems to suggest a possible sawtooth phase noise creation. Talking with a > person "clive1" on the uBlox forum it sounds like the internal GPS engine >>> MAY<< now running at 384MHz there sounds like a possibility to align a > 1PPS edge to a much finer resolution clock which is closer tied to the GPS > solution and thus less digital divider phase noise might be possible. > > Does it sound like I'm way out in left field here? Anyone have the > luxury of more insight into the construction of the uBlox F9 GPS engine? I > don't mind spending a few grand on some factory new components to get a > decent 10MHz standard, but I'm less interested in doing so if I'm not going > to understand what's going on inside. > > Thanks in advance for responses, > > -Tim Strommen > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.