Hi The full answer is always "that depends". The simple answer is that you will sacrifice Q as you make the resonator smaller, regardless of it's shape.
Bob On Mar 13, 2012, at 5:40 PM, ALAN MELIA <[email protected]> wrote: > Hi Bob thanks for that. In replying to Atilla's query I did hope to trigger > some responses that would update my knowedge as well. My experience of > resonators is some 40 years old. Do you know if the older more massive blanks > have a higher "Q" than these small bar ATs. All the high quality resonators I > have come across have been relatively massive. > > Alan > > --- On Tue, 13/3/12, Bob Camp <[email protected]> wrote: > >> From: Bob Camp <[email protected]> >> Subject: Re: [time-nuts] quartz crystal configuration in small cases >> To: "'Discussion of precise time and frequency measurement'" >> <[email protected]> >> Date: Tuesday, 13 March, 2012, 21:10 >> Hi >> >> The typical AT low cost crystal is an AT strip. It's >> rectangular rather than >> circular. It still resonates across the thickness dimension, >> just as the >> circular part does. >> >> A modern 32 KHz crystal is set up as a tuning fork. >> The resonance happens >> each "arm" along it's length. Long ago 32 KHz crystals were >> made as strips >> that resonated along the length of the strip. A part that >> resonates along >> it's length is often called a bar in the literature. >> >> Bob >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] >> On >> Behalf Of ALAN MELIA >> Sent: Tuesday, March 13, 2012 4:47 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] quartz crystal configuration in >> small cases >> >> hi Magnus the only "bar" resonators I have actually seen >> were NT flexural >> bar. Modern cuts probably include all sorts of resonator >> modes....but are >> these AT cuts? >> >> Alan >> >> --- On Tue, 13/3/12, Magnus Danielson <[email protected]> >> wrote: >> >>> From: Magnus Danielson <[email protected]> >>> Subject: Re: [time-nuts] quartz crystal configuration >> in small cases >>> To: [email protected] >>> Date: Tuesday, 13 March, 2012, 17:59 >>> On 03/13/2012 06:35 PM, ALAN MELIA >>> wrote: >>>> Hi Atilla, I dont have book availabe but AT cut is >> a >>> thickness-shear vibration mode so plate area may not be >> an >>> issue ?? Just harder to make :-)) >>> >>> One of the AT cut oscillators I use has a crystal bar >> rather >>> than a circular plate. Being mass-produced in bulk, >> etched >>> etc. It is just a different process. >>> >>> I'm sure the crystal oscillator folks here could point >> to >>> some good sources on that. >>> >>> 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. _______________________________________________ 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.
