Hi For the $50 to $100 cost it's tough to beat a Thunderbolt. It's overkill for the application, but easy to find.
Bob On Jul 2, 2010, at 6:45 AM, Paul Nicholson wrote: > David Partridge wrote: > > Is this a timing GPS receiver, or a generic fast start > > navigation receiver? > > Just an ordinary nav GPS, Garmin model GPS16HVS intended > I think for marine/vehicle applications. Spec says cold > boot 45 seconds, warm boot (position unchanged) 38 seconds. > Measured warm boot is about 25 seconds. > > I haven't sent any setup commands to the thing, it is just > running with out-of-the-box defaults. > > The 1PPS is specified at +/-1uS accuracy, which is fine for > this application if the error averaged to zero (which it > probably does) and was randomly distributed (which it > appears not to be). > > My target for VLF phase error is +/- a few degrees at 77.5kHz, > ie about +/- 0.1uS accuracy, and naively I thought I could > reach this by a moving average of 100 seconds to smooth out > the quoted 1uS jitter of the PPS. But that assumes random > jitter! > > But this 50 minute cycle of about +/- 1.5uS is a bit of a > show stopper. Pity, the GPS16 is a nice unit in every > other respect. > > I'm trying to avoid using any specialised, hard to obtain, > GPS. Will have to order some other types and hope they > have different, better behaved, chip sets. Recommendations > welcome. > -- > Paul Nicholson > http://abelian.org > -- > > _______________________________________________ > 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.