Hi
> On Jan 21, 2017, at 10:25 AM, jimlux <[email protected]> wrote: > > On 1/20/17 7:10 PM, Bob Camp wrote: >> Hi >> >> There are several other materials that you can make crystal resonators out >> of that >> are piezo electric. Some of them can give you much higher Q. This comes with >> a whole >> raft of other issues. Langesite is one of the more common materials you see >> people >> playing with. It is common enough that I’ve actually played with it myself. >> The simple >> answer is that when you look at cost, Q, and stability (aging, ADEV, >> temperature) — >> it is tough to beat quartz. If you have a few hundred thousand dollars, you >> can play >> with great big chunks of Sapphire. Toss in a bit of this and a bit of that >> and you can get a >> pretty amazing oscillator. That device may (or may not) be < $1,000,000 >> depending >> on how you do the accounting and how many parts you spread the costs over. > > > would not a true time nut grow their own sapphire? Or at the very least spend some quality time digging a 100 lb lump up out of the Australian outback …. > > Realistically, isn't it all about the crystal lattice.. SiO2 vs Al2O3 vs > Lanthanum Gallium Silicate vs Lithium Niobate > > WHat makes a "good" material? I would think the ability to grow a very > uniform crystal is part of it, but are certain crystal forms better than > others? Indeed you need a “well grown” crystal and figuring out how to grow them without adding a bunch of stress, contamination, and imperfections in the lattice is a very big deal. Past that, for Q you get into the acoustic loss properties of the material. Some materials are less lossy than others. It is no different than picking a microwave dielectric in that regard. Some of the fun and games involved is measuring the acoustic properties of all these materials. Bob > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
