Hi > On Jan 8, 2017, at 11:21 AM, Dr. David Kirkby (Kirkby Microwave Ltd) > <drkir...@kirkbymicrowave.co.uk> wrote: > > On 8 January 2017 at 15:22, Bob Camp <kb...@n1k.org> 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 -- 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.