[time-nuts] AN/URQ13 reference AT cut crystal?

[Magnus Danielson]

Hi,

On 2021-02-18 12:53, Poul-Henning Kamp wrote:
> --------
> Bob kb8tq writes:
>
>> Turning an “idea” into a production capable part involves making many 
>> batches of test samples. Think in the thousands of batches and hundreds
>> of parts in each batch. You have a “search” process at the blank chopping
>> level. You also have a search at the resonator fabrication level. Getting the 
>> chopping part right is only a small part of the whole process….
> I realize this used to be a manual process, but today I would expect
> that you could automate a lot, of not most of it, if you wanted to ?
>
> It would still be a lot of work, and very expensive, but like
> biochemist trying out hundred of thousand compounds from their
> "libraries", robots really lower the cost.
>
> The real question must therefore be, if anybody reasonably expects
> there to be any superior "new" cuts to find in the first place ?
>
> What properties would you program a quartz-crystal-prototyping robot to search for ?
>
> Which parameter(s) of current crystal-cuts are "their weak point" ?
>
So, keeping a high Q*f product is one. Being able to find small shapes
for SC-like properties. That while retaining much of the benefits that
come from previous developments including reduced strain mounting etc.
etc. The G-sensitivity and vibration sensitivity has not really moved
much, and there is market for that.

Competition from MEMS is for sure becoming fiercer.

I'm sure Bob can mention more stuff, but these are some from my horizon.

I can't recall seeing much SC-cut in 5x7 mm, and that is consider HUGE
these days. OCXO? Not so much. Going the SC-cut route without OCXO seems
rare to say the least. There is the MCXO using the C-mode resonance, but
that's not directly volume product.

Cheers,
Magnus