Hi The big deal with the BVA is that the blank is “isolated” from the mount by a set of slots in the blank edge. That lets them achieve single plane stress isolation. The intent is to reduce the impact of holder stress as part of aging. Moving the electrodes off of the blank is intended to reduce the stress effects of the thermal mismatch between the electrode and the quartz.
There are still *plenty* of reasons for the resonator to age, so no, this does not take aging out of the picture. Bob > On Dec 8, 2017, at 2:05 PM, Tom Knox <[email protected]> wrote: > > Happy Holidays Magnus! What I was wondering was that the BVA is somewhat > unique since other oscillators have metal directly deposited over the quartz > resonator, where the BVA is capacitive coupled. I was wondering if that made > the quartz age less if at all. > > Cheers; > > Thomas Knox > > > > ________________________________ > From: time-nuts <[email protected]> on behalf of Magnus Danielson > <[email protected]> > Sent: Friday, December 8, 2017 11:32 AM > To: [email protected] > Cc: [email protected] > Subject: Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3 > > Hi, > > There is sources of drift all over the place. > > The crystal has drift in it, the oscillator core has sources of drift. > > Already within a crystal there is a bunch of sources. Some can > compensate each other. > > Improvements in production have reduced effects, but there is always > something that drifts, somewhat. > > Cheers, > Magnus > > On 12/08/2017 06:27 PM, Tom Knox wrote: >> Hi All; >> >> Is the "Aging" generally related to the quartz, or other components? >> >> Happy-Merry; >> >> Thomas Knox >> >> >> >> ________________________________ >> From: time-nuts <[email protected]> on behalf of Bob kb8tq >> <[email protected]> >> Sent: Friday, December 8, 2017 9:58 AM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3 >> >> Hi >> >> One risk is that the oscillator may have drifted further than one can easily >> adjust it by >> just changing a select cap. That seems silly when we are talking about < 1 >> ppm, but >> the 8600 is an unusual OCXO. The electrodes BVA is not your run of the mill >> crystal. >> The “air gap” (actually a gap in vacuum) puts a pretty small capacitance in >> series with >> the normal crystal equivalent circuit. That cuts the practical tuning range >> down quite >> a bit…. >> >> Bob >> >>> On Dec 8, 2017, at 11:44 AM, Magnus Danielson <[email protected]> >>> wrote: >>> >>> Hi, >>> >>> Many include a EFC offset pot, but when you go out of range on that, as I >>> have for one of mine, here is no real option execept pop the lid and >>> potentially find a cap or change a cap. I have not seen any as I recall, >>> but should maybe take a look. >>> >>> However, the value for me is not to have it as sharp 5 MHz source, but very >>> low phase noise and high stability source as reference for measurement. The >>> offset error is less of a concern then, so that is why I have not spent >>> quality time to fix it. >>> >>> Cheers, >>> Magnus >>> >>> On 12/08/2017 04:52 PM, paul swed wrote: >>>> I took a quick look at the spec sheet. >>>> It appears coarse adjustment is an option M and would actually be a pot. >>>> That speaks to another tuning diode for coarse? Or a pot on pot >>>> arrangement. >>>> That sounds ugly. >>>> Regards >>>> Paul >>>> WB8TSL >>>> On Fri, Dec 8, 2017 at 10:17 AM, Bob kb8tq <[email protected]> wrote: >>>>> Hi >>>>> >>>>> It is quite possible that nothing is actually broken and that the crystal >>>>> has simply drifted >>>>> outside the tuning range. It should be pretty easy to spot the coarse >>>>> tuning device once >>>>> the package is open. I would bet you will find a selected capacitor across >>>>> the coarse tune or in >>>>> series with the coarse tune. Changing the value of that cap should bring >>>>> things back on >>>>> frequency. I would avoid changing caps across the EFC tuning diode. >>>>> >>>>> Bob >>>>> >>>>>> On Dec 8, 2017, at 8:05 AM, Ulf Kylenfall via time-nuts < >>>>> [email protected]> wrote: >>>>>> >>>>>> >>>>>> Gentlemen, >>>>>> We have an Oscilloquartz OCXO 8600-3that cannot any longer be adjusted >>>>> into 5,000,000 Hz.It is about 1 Hz out of 5 MHz and turning >>>>> coarse/fineadjustment potentiometers cannot bring the frequencyinto its >>>>> specification. >>>>>> Oven temperature is about + 80C accordingto the thermistor and the >>>>> operating voltageis at 24 VDC. >>>>>> Have Googled but the only thing that turns upis datasheets w/o any >>>>> details. >>>>>> Before I take it apart and start lookingfor obviously broken components, >>>>> isthere anyone that has a CLIP on this unit? >>>>>> 73 >>>>>> >>>>>> Ulf Kylenfall - SM6GXV >>>>>> _______________________________________________ >>>>>> 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 > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > >> time-nuts Info Page - American Febo >> Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > >> www.febo.com<http://www.febo.com> > American Febo Enterprises<http://www.febo.com/> > www.febo.com > Welcome to American Febo Enterprises! Welcome to American Febo Enterprises, a > proud subsidiary of International MultiGeek. AFE is an intergalactic > consultatorium ... > > >> time-nuts is a low volume, high SNR list for the discussion of precise time >> and frequency measurement and related topics. To see the collection of prior >> postings to ... >> >> >>>> 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 > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > >> time-nuts Info Page - American Febo >> Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > >> www.febo.com<http://www.febo.com> > American Febo Enterprises<http://www.febo.com/> > www.febo.com > Welcome to American Febo Enterprises! Welcome to American Febo Enterprises, a > proud subsidiary of International MultiGeek. AFE is an intergalactic > consultatorium ... > > >> time-nuts is a low volume, high SNR list for the discussion of precise time >> and frequency measurement and related topics. To see the collection of prior >> postings to ... >> >> >>> 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 > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > >> time-nuts Info Page - American Febo >> Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > >> www.febo.com<http://www.febo.com> > American Febo Enterprises<http://www.febo.com/> > www.febo.com > Welcome to American Febo Enterprises! Welcome to American Febo Enterprises, a > proud subsidiary of International MultiGeek. AFE is an intergalactic > consultatorium ... > > >> time-nuts is a low volume, high SNR list for the discussion of precise time >> and frequency measurement and related topics. To see the collection of prior >> postings to ... >> >> >> 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 > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > >> 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 > time-nuts Info Page - American Febo > Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > www.febo.com > time-nuts is a low volume, high SNR list for the discussion of precise time > and frequency measurement and related topics. To see the collection of prior > postings to ... > > > 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.
