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.