Rick, On 03/03/2018 03:30 PM, Richard (Rick) Karlquist wrote: > I asked the CBT manager at Microsemi about this > rumor and he disavowed any knowledge of this. > He told me they were making 8 a week (not clear > if this is just 5071A's, or includes replacement > CBT's). I don't remember the production ever > being anywhere near this level. The reason > for the relatively brisk sales is that the risk > of GPS spoofing means that various military and > 3 letter agencies need to own dedicated 5071's. > With a large installed base of 5071's, there will > be a guaranteed market for replacement tubes. > The US government considers the 5071A to be of > great strategic importance and would be certain > to "encourage" its continued production in case > of any business reorganization. > > When we designed the 5071A twenty five years ago, > it seemed that there were two safe bets: > > 1. Working Cs standards (outside the lab) would > obsoleted by what HP called "smart clocks" running > off of GPS.
We sure have seen more or less "smart" clocks being put into use an decommissioned for hobbyists delight. > 2. Magnetic state selection, as used in the 5071A, > would be replaced by optical pumping. Len Cutler > was heartbroken that HP/Agilent management wouldn't > fund this effort. Interestingly enough, Oscilloquartz claim to have one, showcasing it etc. but it's been "coming real soon" for a bit of a time now. I do not know how that progresses. > It turns out that, even now in 2018, optical pumping > is not ready for prime time in a working standard > because the lasers drift over time. Moving a technology from the lab environment into production is indeed a challenge. > The 5071A's claim to fame is that you turn it on and it just > works ... until it runs out of cesium. That is > another reason the 5071A isn't going away any time soon. It belongs clearly to the moderns cesiums which just operates and trims up itself well. In my basement I currently have two where one had a workiing CBT and failing electronics while the other had failed CBT and working electronics. So I got to long-time borrow them to swap tubes and use them. :) Cheers, Magnus _______________________________________________ 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.
