Post by thread:[OT] X-Tal question

>I was wondering how many Khz you can change the crystal's frequency (F < >10Mhz) with changing the caps... They're not designed to be changable at all. That's the whole point of a crystal. Ideally, it wouldn't be possible to change them at all. The old military HF xtals were in little boxes, and you could open the box, take out the rock, and grind it with Ajax, or rub a little solder on it, and alter the frequency.

Hi all, Even though in most apps you don't want to change them, most if not all CAN be changed slightly. I think that a general rule of thumb is around .1 % of their frequency (so about 1kHz per MHz, or 10kHz in your case). I know this from building VXCO (variable xtal oscillator) driven amateur radio QRP (low power) transmitters. Sean At 02:32 PM 10/24/98 -0500, you wrote: {Quote hidden}>>I was wondering how many Khz you can change the crystal's frequency >(F < >>10Mhz) with changing the caps... > > >They're not designed to be changable at all. That's the whole point of >a crystal. >Ideally, it wouldn't be possible to change them at all. > >The old military HF xtals were in little boxes, and you could open the >box, take out the rock, and grind it with Ajax, or rub a little solder >on it, and alter the frequency. > +-------------------------------+ | Sean Breheny | | Amateur Radio Callsign: KA3YXM| | Electrical Engineering Student| +-------------------------------+ Save lives, please look at http://www.all.org Personal page: http://www.people.cornell.edu/pages/shb7 spam_OUTshb7TakeThisOuTcornell.edu Phone(USA): (607) 253-0315 ICQ #: 3329174