After keeping an old EFOS 2 H maser running the last couple or three years here are a few bits of advice.
-The triple magnetic shields are VERY important. The first time I removed the top shield to access the RF section the Maser stopped oscillating! Replacing the shield restored oscillations! -The cavity does not have to be machined to "super precise levels", in this Maser once the coarse setting (mechanical at factory) is made, the medium tuning is done by adjusting the cavity temperature. The fine is done with the cavity varactor. This cavity is aluminum. -from a cold start it takes about 1 week for the ovens to come up to operating temp.! -this maser has two vacuum sections, an outer that enclosed the cavity and thermally insulates it. This allows the cavity temperature to be regulated to within .001 degree C. The inner chamber keeps the cavity evacuated so all you have in it is the H atoms. -Making a homebrew collimator (at the discharge bulb output) might be hard, google it and you will see it's tricky. -As stated the electronics are pretty easy these days. Main points are a low Insertion loss, high isolation circulator on the cavity output, a low noise figure RF amp and a low noise downconvertor. I have, somewhere, a scan of the two manuals. There is lots of theory and full schematics. Might be a good read if you are serious in trying to homebrew one. I'll dig them up and see if anyone could host them on a website. (Files are quite large!) Corby Dawson ____________________________________________________________ 1 Tip for Losing Weight Cut down 2 lbs per week by using this 1 weird old tip http://thirdpartyoffers.juno.com/TGL3141/4c7ac2d3136f9d283cm04duc _______________________________________________ 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.