[time-nuts] Bye-Bye Crystals

[Attila Kinali]

On Mon, 13 Mar 2017 15:01:39 +0000
Adrian Godwin <artgodwin at gmail.com> wrote:

> What minimal equipment would you need to make your own crystals ?

The equipment is quite minimal:

* A diamond precision saw to cut the crystals
* Some tool to check the accuracy of the cut (orientation and thicknes)
* a lapping/grinding machine
* an electroplating machine (usually sputtering) for the electrodes.
* either some machine to produce the crystal holder yourself or buy them
* vacuum system to evacuate the crystal holder and to bake everything
* something to (cold) weld the case close


All of this can be put in a (relatively) small workshop.
The difficulty is also not producing quartz crystals
in holders. The difficulty controlling the whole process
to such an degree that you get high quality crystals
at the frequency you want.

If you managed to do that, you can further improve
your system by using a BVA[1,2] like geometry, where
the electrodes are not on the resonator itself but
on the surrounding crystal, which acts at the same
time as holder.
But be warned, many attempted to re-create the BVAs
but few succeeded... and none but Oscilloquartz ever
managed to produce a economically viable product.


			Attila Kinali

[1] http://www.nature.com/articles/srep02132/figures/1
[2] http://www.nature.com/articles/srep02132/figures/2

-- 
It is upon moral qualities that a society is ultimately founded. All 
the prosperity and technological sophistication in the world is of no 
use without that foundation.
                 -- Miss Matheson, The Diamond Age, Neil Stephenson