Bob, I think you're missing the point here. This is not the quest for utimate standards of accuracy/precision/resolution, it Is not about economic viability, or even attainability, let alone being "worth the trouble.".
It is about a fun project. Fun even if it comes to nothing. Is that difficult to understand? On Sunday, January 8, 2017, Bob Camp <[email protected]> wrote: > Hi > > > On Jan 8, 2017, at 11:21 AM, Dr. David Kirkby (Kirkby Microwave Ltd) < > [email protected] <javascript:;>> wrote: > > > > On 8 January 2017 at 15:22, Bob Camp <[email protected] <javascript:;>> > wrote: > > > >> Hi > >> > >> I guess the question then would be: > >> > >> Is a H Maser that runs 6.6 x 10^-12 at 1 second worth the trouble? > >> > >> With 100 KHz / C temperature coefficients running around, getting > >> good stability in a real world setting at 1 day will be “interesting”. > >> > >> Just for reference: The MH-2010 data sheet shows 1.5x10^-13 at > >> 1 second for the “cheap” version and 8x10^-14 at one second for > >> the low noise version. Data showing the 5065 Rb at 1x10^-12 at > >> 1 second is running around on various web sites. > >> > >> The NIST paper suggests that they made several prototypes before > >> they got one good one working. That’s a lot of “fun and games” with > >> ceramic machine lathes and Rb magnetometers….. > >> > >> The punch line being - would the same effort / cost / many years of time > >> be more > >> fruitful (ADEV wise) doing a large package Rb (like a 5065) ? Based on > >> the number of people making them in volume over the years, Rb’s appear > to > >> be the easier item to debug, design, and build. > >> > >> Bob > >> > > > > If you build a H2 maser, you would learn a lot more than building a bunch > > of rubidiums. That sounds a good enough reason to me. > > > I’m not sure I agree with that. Both have their own issues. Much of the > learning > in both cases involves fiddly mechanical and machining details. Working > each > out by a lot of trial and error would be useful for that particular > standard. It’s hard > to see how it would be useful for much else …. Yes, there is a bunch of > obscure > physics involved in each, but again it’s very use specific stuff. > > Bob > > > > > I've been contemplating buying one of the older HP 5061A or 5061B cesium > > frequency standards from eBay. Almost all are sold as "for spares or > > repair", and are probably not going to be economically viable to get > > working due to the fact the tubes are probably useless. But I'd sure > learn > > a lot from playing around inside one of the older ones. > > > > Dave > > _______________________________________________ > > time-nuts mailing list -- [email protected] <javascript:;> > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] <javascript:;> > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > -- If you gaze long into an abyss, your coffee will get cold. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
