How does one tell the difference between "early" and "later" ?
S/N, Rev # ?? 73, Dick, W1KSZ Sent from Outlook<http://aka.ms/weboutlook> ________________________________ From: time-nuts <time-nuts-boun...@lists.febo.com> on behalf of Bob kb8tq <kb...@n1k.org> Sent: Monday, February 4, 2019 7:23 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 10 mhz accuracy for a satellite system Hi One thing to watch on the TBolts - the ocxo’s used in them got better as the years went by. An early one likely will not do quite as well as a later one. They also updated the firmware as time went by, same basic issue - later is probably better …. Bob > On Feb 4, 2019, at 8:51 PM, Richard Solomon <w1...@outlook.com> wrote: > > There have been some Trimble Thunderbolts over on that auction site > that were being sold for $80 each (not surplus Telcom ones). > I grabbed two and they work. > > My antenna was a "hockey puck" style antenna sitting on the window > sash, facing South. > > 73, Dick, W1KSZ > > Sent from Outlook<http://aka.ms/weboutlook> > ________________________________ > From: time-nuts <time-nuts-boun...@lists.febo.com> on behalf of Grant Hodgson > <gr...@ghengineering.co.uk> > Sent: Monday, February 4, 2019 11:15 AM > To: time-nuts@lists.febo.com > Subject: Re: [time-nuts] 10 mhz accuracy for a satellite system > > Paul > > The keyword is GPSDO - GPS disciplined oscillator. The vast majority of > these will give a 10MHz output. The long term accuracy is the same as > the GPS navigation system, which for most purposes is similar to that of > national standards. GPSDOs are more stable than most rubidium standards > in the long term, and GPSDOs are extremely common in most laboratories. > > The Trimble Thunderbolt is very common and available on the surplus > market, as is the HP Z3801A. James Miller (G3RUH) used to sell an > excellent GPSDO. There are other home-brew designs available if you > want to build. These have all been extensively characterised if you > want the details. > > If you want to buy new, then there are products such as the Fury and > Firefly from Jackson Labs; , U-Blox have many offerings (not sure if > they do a GPSDO though). > > Google GPSDO or GPS frequency standard, or check the leapsecond.com > website for more information - there's loads out there, it's just a case > of using the right term in the search engine. > > regards > Grant > >> Date: Sun, 3 Feb 2019 23:43:10 -0000 >> From: "Paul Bicknell" <p...@bicknells.f2s.com> >> To: "'Discussion of precise time and frequency measurement'" >> <time-nuts@lists.febo.com> >> Subject: [time-nuts] 10 mhz accuracy for a satellite system >> Message-ID: <D1F28D64EDD440EC834753538090F381@precision380> >> Content-Type: text/plain; charset="iso-8859-1" >> >> >> Dear all >> I currently use a 198 Khz off air standard but I can no longer use 600 khz >> since it moved from Rugby >> I have herd a lot about varies frequency references that use satellites >> This technology has improved immensely & become more affordable over the >> past 5 years >> >> So can a standard locked to a satellite be as good as a Rubidium ? >> >> What accuracy can I achieve for a satellite system below ?800 as I am not >> familiar with the latest that are on offer? >> >> Regards Paul Bicknell South Coast UK >> >> > > _______________________________________________ > 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. _______________________________________________ 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.