Zero. But the answer is also zero for a Rb or Cs cell!
On Thu, Nov 3, 2016 at 8:59 PM, Bob Camp <kb...@n1k.org> wrote: > Hi > > Ok, how many full performance Hydrogen Masers can you build (size is not > an issue) and > deliver for < $10,000 (2X Bert’s number) ? > > Bob > > > On Nov 3, 2016, at 8:55 PM, Tim Shoppa <tsho...@gmail.com> wrote: > > > > It would obviously be larger than a homebrew Cs, but why not a homebrew > > Hydrogen Maser Frequency standard? > > > > The commercial Cs units always seemed objects of pure miniaturized > hi-tech > > materials science magic, while the Hydrogen Masers I've seen seem much > > larger-scale\ and more a matter of vacuum plumbing. Obviously the > materials > > cost for the copper microwave cavity will be very large, and I'm sure > > Teflon-coating a quartz chamber is an art, but the pumps and magnets are > > very familiar from my years in grad school working with plasma kettles > and > > mass spectrometers. > > > > Tim N3QE > > > > > > > > > > > > On Thu, Nov 3, 2016 at 4:07 PM, Bert Kehren via time-nuts < > > time-nuts@febo.com> wrote: > > > >> > >> Over the past there has been talk about building from scratch high > >> performance references. I think consensus was that it is out of reach. > In > >> the mean > >> time Corby is reworking an active maser which takes a lot of know how. > But > >> let us look at his work on the super HP5065. It is able to outperform a > >> passive maser in the below 100 second range! Long term a proper GPSDO > >> should > >> be possible to step in. We are working on it including pressure and > >> temperature control. To make full use of it you also need to have the > >> capability > >> to monitor, record and analyze on a continuous basis preferably with out > >> tying up expensive equipment. We have the pieces in place and looking > >> forward > >> of combining all the pieces and compare with Corby’s active Maser. We > are > >> back to the GPSDO after being distracted by Tbolt performance. A third > >> party > >> is working combining the GPSDO data stream with the data from the unit > >> that > >> generates frequency, pressure and temperature data along with time to a > >> USB stick, while also be able to monitor with a PC. > >> I know it is considered by some heresy but our lack of a Maser and in > >> Juerg > >> ’s case no access to one, we try to overcome it with a GPSDO tailored > for > >> Rb and Cs and control our Cs’s C field . > >> There was a time that I did have a HP5065A but got rid of it when I got > >> some Cs’s. My best counter was A HP5345 and even with a Tracor 527 1 > >> second > >> performance was not an issue. That changed when Corby introduced me to > >> time > >> nuts and frankly it was the first time I learned about ADEV. But the > >> HP5065A was gone. Now I have a cell that Corby has plotted and time > >> permitting > >> may become a project. > >> Let me get to the real issue. There are not enough HP5065A’s out there > and > >> not affordable for all time nuts. Most are being kept and are not for > >> sale. But if a combined effort by many time nuts it MAY be possible to > >> recreate > >> the guts of the HP5065A. The key word is MAY. 200 time nuts be willing > to > >> invest $ 5000 each may get us there. The market does not justify such > an > >> effort but time nuts keep bringing up discussions. All the other ideas > >> kicked > >> around in the past will cost more. There are some among us that know > what > >> it cost and who can make the key elements like lamps, cells, filters > etc. > >> Just a thought outside the box and hopefully may turn in to a limited > >> constructive dialog. We will continue on our path, which include > >> FRK/M100, HP5065 > >> and Cs. > >> We would not be capable to contribute technically on the physics > package > >> but I would be willing to contribute financially and with monitoring > >> equipment even if I would not be around when finished. > >> Bert Kehren > >> _______________________________________________ > >> 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. > > _______________________________________________ > 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.