[time-nuts] Better quartz crystals with single isotope ?

[Richard (Rick) Karlquist]

On 4/22/2018 10:20 AM, Bob kb8tq wrote:

>> Do we know anybody in the quartz business who needs a really cool
>> research project ?
> 
> You could put it on the list with the 1 Kg quartz resonator proposal …..
> 
> https://tf.nist.gov/general/pdf/2638.pdf <https://tf.nist.gov/general/pdf/2638.pdf>
> 
> Also an offshoot of people thinking about the implications of all this as it relates to resonators.
> 
> 
> Bob
> 

The cited article "must be true" because of its authors, I guess, but it
makes no sense to me.  They seem to be assuming that the resonant
frequency is inversely proportional to mass?  We all know three things:

1.  Frequency is inversely proportional to thickness.  Not mass.

2.  Frequency aging is affected by stress relaxation in well built
resonators.  The old idea that mass is gradually evaporating from
the resonator to the enclosure (glass enclosures) or mass is gradually
evaporating from the enclosure (metal enclosures) to depositing
on the resonator is simply obsolete in terms of current technology.
Thus again frequency is not a proxy for mass.

3. Resonators can "jump" in frequency without jumping in mass.

Given these facts, I am lost as how this is supposed to work.
Surely, the authors are well aware of the 3 items above.

Also, why does the resonator have to be a whole kilogram anyway.
If it weighed exactly 10 grams, couldn't you still compare it
to a kilogram using 100:1 leverage?

Can anyone straighten me out?

Rick