Hi The dielectric constant of water is also highly temperature dependent. If it's a direct dielectric thing, it should show up as a secondary temperature effect.
Bob On Mar 2, 2010, at 6:30 PM, Joseph M Gwinn wrote: > [email protected] wrote on 03/02/2010 04:51:15 PM: > >> From: >> >> "Bob Camp" <[email protected]> >> >> To: >> >> "'Discussion of precise time and frequency measurement'" <time- >> [email protected]> >> >> Date: >> >> 03/02/2010 04:55 PM >> >> Subject: >> >> Re: [time-nuts] Vremya-ch Hydrogen Masers >> >> Sent by: >> >> [email protected] >> >> Hi >> >> Without doing a lot of digging, I doubt we'll find out just what they > did >> (or didn't) find and fix. They certainly started with a "from scratch" >> design. They may have multiple points of departure from the US approach. >> >> Then again, it may just be a better brand of coating they spray on the >> boards. > > It does not take much moisture absorption in printed circuit boards and > conformal coats to cause significant variation in electrical delay with > variation in humidity, given that the dielectric constant of water is > about 80. The solution may be no more complex than use of only > low-absorption materials surrounded by hermetic metal enclosures also > containing a cloth bag of moisture absorbing chemical granules. > > Joe > > >> Bob >> >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf Of Magnus Danielson >> Sent: Tuesday, March 02, 2010 3:05 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] Vremya-ch Hydrogen Masers >> >> Bob Camp wrote: >>> Hi >>> >>> I hear that the US ones look better than the Russian ones when you > have >> them >>> spinning around on a frozen pond. Nether one does a very good >> triple axle >>> jump though. At least that's what I read on the internet.... >>> >>> --------------- >>> >>> There's always been a *lot* of debate about exactly what the source of >>> humidity impact on the US built masers is. It's been talked >> about for at >>> least 30 years. It's not real surprising if somebody >> somewhere has found >> the >>> answer and fixed it. >> >> Rather, what did the Russians figure out and fixed? >> >> 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. >> >> >> >> >> _______________________________________________ >> 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. > > > _______________________________________________ > 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. > _______________________________________________ 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.
