Yes, it is: the CW12 has the PPS derived from the 100MHz clock and that's why you have that PPS granularity with no need for a sawtooth correction.
On Thu, Mar 29, 2012 at 7:18 PM, paul swed <paulsw...@gmail.com> wrote: > OK been only slightly paying attention. > But I see in the US several sellers for a operational board at $84-89. > Maybe I have the wrong unit but it does say 5ns or less timing error > Regards > Paul > WB8TSL > > On Thu, Mar 29, 2012 at 11:50 AM, Ed Palmer <ed_pal...@sasktel.net> wrote: > > > On 3/29/2012 12:54 AM, Ulrich Bangert wrote: > > > >> Thomas, > >> > >> The sawtooth error on the Motorola M12+ is about +/- 25ns, while the > >>> CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the > >>> sawtooth error is not as critical with the CW12-TIM. > >>> > >> The first claim > >> > >> The sawtooth error on the Motorola M12+ is about +/- 25ns > >>> > >> is correct but are you absolutely sure that the second claim is correct > >> too????? > >> > >> It would mean a factor>10 improvement of the CW12-TIM against the M12 > >> which > >> is hardly believeable. > >> > > > > Believe it. I've made multiple test runs where I use an HP 5372A to > > measure 1000 pulses of the CW12. The Standard Deviation is always < 5 ns > > with a max-min range of < 30 ns. That's without any type of error > > correction - straight from the GPS receiver to the 5372A. A clue to the > > performance is a line in the datasheet that says the clock speed is "up > to > > 120 MHz". Maybe not fast enough to justify +/- 2 ns., but in the ball > park. > > > > I am rather surprised that they're adding sawtooth correction. This unit > > has been around for some years. The Motorola firmware isn't even a > > standard offering anymore. You have to ask for it. It'll be interesting > > to see what they come up with considering that the datasheet says that > the > > resolution on the 1 PPS signal is "< 5 ns". There doesn't seem to be > much > > room for correction there. > > > > Ed > > > > > > Best regards > >> Ulrich Bangert > >> > >> -----Ursprungliche Nachricht----- > >>> Von: time-nuts-boun...@febo.com > >>> [mailto:time-nuts-bounces@**febo.com <time-nuts-boun...@febo.com>] Im > >>> Auftrag von Tom Knox > >>> Gesendet: Mittwoch, 28. Marz 2012 20:42 > >>> An: Time-Nuts > >>> Betreff: [time-nuts] CW12-TIM vs M12M and the world > >>> > >>> > >>> > >>> I spoke with Navsync about some of the issues we are > >>> discussing and this was their response. I just received mine > >>> and will try to test it over the weekend. 1. Is CW12-TIM > >>> compatible with Motorola M12 ?>> The CW12 is designed to be > >>> compatible with the M12 although there are > >>> some differences. The main hardware differences are listed > >>> on page 7 of the CW12 User Manual > >>> (http://www.navsync.com/docs/**cw12-tim_um.pdf< > http://www.navsync.com/docs/cw12-tim_um.pdf>). > >>> 2. According > >>> to the customer, M12 has a Sawtooth Correction Error& > >>> Hanging Bridge Error? Does CW12 have a solution for these type of > >>> errors? How these errors are taken care of in CW12?>> > >>> The Hanging Bridge Error is a pattern seen in the sawtooth > >>> error that > >>> occurs as the local clock frequency changes. The standard Motorola > >>> Binary software for the CW12-TIM does not have the sawtooth > >>> correction > >>> field in the @@Hn command implemented, but NavSync is currently > >>> developing this and it will be available in future standard releases. > >>> The sawtooth error on the Motorola M12+ is about +/- 25ns, while the > >>> CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the > >>> sawtooth error is not as critical with the CW12-TIM. > >>> > >>> Thomas Knox > >>> > >>> > > ______________________________**_________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/** > > mailman/listinfo/time-nuts< > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.