Hi The only thing that the 5 MHz 3rd crystal is “optimum” for is a holder that will accept a 0.55” max diameter blank.
Bpb On Nov 2, 2013, at 6:06 PM, Tom Knox <act...@hotmail.com> wrote: > Mike I think we must be talking to the same smart people. I think 5MHz was > adopted over 3MHz simply because 5MHz multiplies to other commonly used > frequencies with greater ease. I think the top frequency standards have > evolved to 5MHz Third Overtone SC cut crystals for a reason. The evolution > has gone on from the days of Tesla and improved greatly during the glory days > of Quartz in the years leading up to atomic standards with countless hours of > experimentation and research. Those lessons learned are constantly examined > through the lens of the latest science. I may be wrong, but I have not > heard of any extreme design prototype quartz oscillator with superior Phase > Noise and Stability. Our house standard F1 a cesium fountain is used roughly > one month every few months to characterize roughly 12 5071A cesium standards > steering about 5 MHM 2010 cleaned up with a number of 8607 option 08 > oscillator. (The equipment choices are not a recommendation or endorsement, > and there are po > ssibly m > any product that could meet or exceed the performance of these fine > products.) But the oscillators selected are 5MHz third Overtone SC cut. > > Thomas Knox > > > >> From: mfe...@eozinc.com >> To: n1...@alum.dartmouth.org; time-nuts@febo.com >> Date: Sat, 2 Nov 2013 09:50:50 -0400 >> Subject: Re: [time-nuts] The 5MHz Sweet Spot >> >> Exactly - I mentioned this on here about 3 years ago and all of the >> self-proclaimed geniuses poo-pooded it. I was told early in my engineering >> career in the early 70's, by a very smart man, when I thought I had all of >> the answers, that considering all of the trade-offs regarding performance, >> around 3 MHz for a crystal is best, operating in the 3rd overtone mode, >> hence the slow progression from the 1 and 5 MHz standards to 10 MHz. Now, >> getting close to 70, I just see what I can learn from all the "smart" people >> on here, and keep quiet most of the time. Regards - Mike >> >> Mike B. Feher, EOZ Inc. >> 89 Arnold Blvd. >> Howell, NJ, 07731 >> 732-886-5960 office >> 908-902-3831 cell >> >> -----Original Message----- >> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >> Behalf Of David McGaw >> Sent: Saturday, November 02, 2013 1:30 AM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] The 5MHz Sweet Spot >> >> This all seems to be forgetting that the crystals are usually operated at >> 3rd or 5th harmonic. The crystal in a 10811A is 10 MHz/3rd overtone. A >> high quality 5 MHz/5th overtone crystal is really a 1 MHz fundamental, a >> large piece of quartz. Running at a harmonic greatly reduces the influence >> of the package. >> >> David >> >> >> _______________________________________________ >> 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. _______________________________________________ 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.
