On Wed, 3 Sep 2008, raypsi wrote:

Hey Gary,

Rocks aren't cheap he http://www.icmfg.com/thruhole_crystals.html
Maybe in 9 land they pave the streets with gold.
Personally I'd go with a programmable divider or PLL.

Maybe you like retro, then I'd get some old rocks the ones
you can take apart and grind them down to git's the freq's you need.

And you can't grind them unless they are quite close to the desired
frequency. Grinding by hand will be too uneven, so the crystal will
stop working if you try to grind it more than a tiny bit.

It also relies on a big stock of crystals spread around so you can
find one sufficiently close enough, something that did seem possible
in the years after WWII, but after all this time attrition may have
reduced the stock considerably.

And realistically, they also have to be bulky FT-243 holders, since
those you can open by removing screws, and the blank is held in place
with pressure. More recent holder types require desoldering the case,
and figuring out how to remove the blank and then get it back in place
when it's soldered in place (or something like that I can't remember how
the blank is connected).

One of the odd things is that if one has to buy new crystals, a
synthesizer will likely be far cheaper. In the early seventies,
synthesizers made a big splash because everyone wanted lots of channels
on 2m FM, and the need to have them ground to frequency (and to equipment)
made it all very costly, so synthesizers despite their cost and bulk
became the norm.

Almost forty years later, a synthesizer for a handful of crystals would
still be comparatively bulky, but would be even cheaper than in the early
seventies.

Michael VE2BVW