Hi
> On Mar 26, 2016, at 2:49 PM, Alex Pummer <a...@pcscons.com> wrote: > > I am perhaps to late now,I found the e-mail recently: > " >> sockets can be an issue. With wire leads, you are asking for trouble. >> >> Functionally, there is little there is little difference between a glass > > package crystal > >> and a metal package. About the only real one is the obvious - one has a metal > > shield > > you can (but sometimes don’t) ground. > > Bob > > > " > > > the glass packed ones will have much better vacuum, therefore higher Q > I still have some KVG glass envelope crystals [116MHz overtone] from the 60 > -ties That may have been true in the 1950’s but once modern cold weld packages came along it quickly became a non-issue. The Q dependance of crystals to atmosphere is a function of frequency. A 118 MHz crystal shows much less impact from a given level of “air” than something like a 2.5 MHz 5th overtone. Bob > 73 > KJ6UHN > Alex > > On 2/2/2016 2:37 PM, Bob Camp wrote: >> Hi >> >> I think you will find that the Russian versions were used without ovens for >> a long time. In the US, the only >> use for the glass packages past the mid 1960’s was in ovens. >> >> Bob >> >> >>> On Feb 2, 2016, at 1:43 PM, iovane--- via time-nuts <time-nuts@febo.com> >>> wrote: >>> >>> I think that these crystals were designed to be placed in an oven, which >>> worked >>> as a shield too. I have a similar crystal made by Racal in the 60's, and in >>> my >>> case it is fitted with the classic octal tube-type plug. It was housed >>> (still >>> is) in a heavy massive shimmering chrome-plated cylindrical brass >>> enclosure, a >>> beauty to see, It was the timebase of a tube-type synthesizer with lots of >>> tubes. Themperature control was achieved by means of a mercury thermometer >>> in >>> which mercury actuated a contact when reaching a wire crossing the capillary >>> tube. >>> >>> Antonio I8IOV >>> >>>> Da: Bob Camp <kb...@n1k.org> >>>> Data: 02/02/2016 13.15 >>>> A: "Discussion of precise time and frequency >>>> measurement"<time-nuts@febo.com> >>>> Ogg: Re: [time-nuts] Glass Envelope Quartz Crystals >>>> >>>> Hi >>>> >>>> Since the 25 MHz crystal has already been soldered into a circuit, putting >>>> it >>> in a >>>> socket is probably not a real good idea. It’s also a leaded part. Even with >>> fat pins >>>> sockets can be an issue. With wire leads, you are asking for trouble. >>>> >>>> Functionally, there is little there is little difference between a glass >>> package crystal >>>> and a metal package. About the only real one is the obvious - one has a >>>> metal >>> shield >>>> you can (but sometimes don’t) ground. >>>> >>>> Bob >>>> >>>> >>>>> On Feb 1, 2016, at 9:58 PM, Daniel Watson <watsondani...@gmail.com> wrote: >>>>> >>>>> Hi, >>>>> >>>>> I purchased a pair of interesting glass envelope crystals for a project. >>>>> Here are some pictures: >>>>> >>>>> http://syncchannel.blogspot.com/2016/02/glass-envelope-quartz-crystals.html >>>>> >>>>> Does anyone have an idea about what mount/socket I should buy for these? I >>>>> read a previous thread on the list about Bliley crystals using a B7G >>>>> mount, >>>>> but I'm not sure if that type might work here. >>>>> >>>>> Also, when building up a circuit to make these oscillate, are there any >>>>> specific differences about crystals in this package that I should keep in >>>>> mind? >>>>> >>>>> >>>>> Thanks much, >>>>> >>>>> Dan W. >>> >>> _______________________________________________ >>> 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. >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2016.0.7497 / Virus Database: 4545/11889 - Release Date: 03/26/16 > > _______________________________________________ > 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.