I'm not familiar with the E1938, but the 10811, I believe is one of the small "hi stab" units that HP put into their higher end counters. It uses a single oven where the 103 and 107 used double ovens. Incidentally, the 103 uses a 1 MHz rock and the 107 uses a 5 MHz rock. -Mike-
At 03:27 PM 2/19/2008, you wrote: >Mike Fahmie wrote: > > Somewhere, I have a NASA pub that describes a technique using Gamma Rays > > to > > accelerate aging so that later aging is much reduced, can't seem to find > > it > > now. I would guess that the radiation cause the stresses to relax. NASA > > was > > evidently interested because satellites experience a lot more radiation > > than we receive here on the surface and it probably caused a rapid > > frequency shift in otherwise unradiated crystals. > >I remember some of the crystal gurus talking about this. >I suspect it didn't pan out or everyone would be doing it. >I also remember them saying that radiation causes "color centers" >to appear. > > > I have two HP quartz oscillators that I've been running and logging for > > well over a decade. They run 24/7 and are on battery backup. The HP-103 > > shows about 6 parts in 10^-12/day and the HP-107 about 2 parts in > > 10^-13/day. I attribute this to steady temperature and solid mounting in a > > heavy rack. > > > > -Mike- > >That's incredible Mike. I've never seen a 10811 or E1938 within a >factor of 10 of the first number you gave, let alone the second. >The second rate would be very respectible for a Rb standard. >I believe those antique oscillators you have are using non-HP >made xtals at 1 MHz (or 5 MHz at the most) in glass packages. >While a steady temperature and solid mounting is great, it takes >more than that to put up these kind of numbers. Congratulations, keep >taking good care of those old war horses. I wish Len Cutler were >still around to tell about it. He proudly keep a 107 prototype >in his office. Len couldn't bring himself to design anything that wasn't >a doomsday machine. > >Rick Karlquist, N6RK > > >_______________________________________________ >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.
