[R-390] 17 MHz Crystal

[Barry]

Is that ratio expressed correctly?  It seems that should be a diameter to thickness ratio > 100 (or it's Wednesday and I'm not thinking clearly...).

Thanks,
Barry - N4BUQ

> Hi
> 
> In a crystal like the one shown the frequency is determined by the
> thickness. That's generally true of any crystal in the > 1 MHz
> frequency range. To make things work ( Q / resistance / trim range)
> you need a thickness to diameter ratio > 100. That all gets
> impractical as you go down in frequency, so you go to cuts that
> resonate in other ways.
> 
> Bob