Is it possible to tune the crystal frequency by varying the driving components?

See the first diagram on http://www.z80.info/uexosc.htm

 

Only in a fine tweak manner, you can move the last few digits around. The whole point of the crystal is frequency doesn't shift much. Make one of the 20pf variables.

 

This is probably a hijack but a curiosity from my past. In the 60's a class mate was a keen ham operator. In those days one could extract the crystal from the holder itself. He mentioned to me he was up-shifting a crystal by "grinding" it on a flat surface with toothpaste as the grinding medium. I loved the practical bent that ham operators seemed to manifest as a matter of course.

 

This is probably a hijack but a curiosity from my past. In the 60's a class mate was a keen ham operator. In those days one could extract the crystal from the holder itself. He mentioned to me he was up-shifting a crystal by "grinding" it on a flat surface with toothpaste as the grinding medium. I loved the practical bent that ham operators seemed to manifest as a matter of course.

I don't think I want to go to this extreme to change a frequency. After I grind off some of the crystal, I would need to test the frequency. Then propablely grind off some more, remount the crystal, and so on .....

 

Depends on how much you want to change the frequency. Crystals are stable to about 5 ppm. You can tweak it around 50 ppm, 0.005% that's it.

 

That first circuit re post #1 has a pot to adjust the xtal drive, that pot will probably allow some trimming of freq itself.