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: [email protected] [mailto:[email protected]] 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 -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
