[time-nuts] The 5MHz Sweet Spot

[Richard (Rick) Karlquist]

On 11/1/2013 8:28 PM, Bob Camp wrote:
> HI
>
> If you doubled the diameter of the blank each time you cut the frequency in half, all sorts of nice things might happen. If you start with a 1/2” blank in at 10 MHz that goes to 1” at 5 MHz and 2” at 2.5 MHz. Around 1 MHz you would get to a 5” blank.
>
> Good luck finding high grade quartz bars to cut 5” (or even 1”) blanks out of. You are going to have to go back to the autoclave fixtures at the very least. Since growth is (at best) linear you cost of quartz will scale with the size of the blank. I’d bet it scales a bit more than that if you want to keep the material at a high level of performance.

You've explained the excuses vendors give for not making full
size crystals.  But the question is, given these realities,
does this reduce the theoretical advantage of the lower frequency
and by how much?

Rick Karlquist N6RK