In message , Registered User
writes
On Wed, 3 Sep 2008 14:54:17 -0400, Michael Black wrote:

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.

My personal experience is an FT-243 crystal's frequency can be
increased by several hundred kilohertz through grinding. A more
abrasive media is needed for the slurry than scouring powder can
provide. Permatex 34A valve grinding compound works FB. Most of my 80M
rocks (26 between 3.5 & 3.6 MHz) were originally cut for 3237 kHz.
Many of my 40M crystals were moved several hundred kHz as well.

The key to grinding is not to try doing too much at once. Let the
abrasive do the cutting, no downward pressure is need from the
fingers..

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.

There are still a lot of them out there and they can be most
inexpensive if the actual frequency isn't too important.

73 de n4jvp

All this discussion about crystal grinding is very interesting. From my
far distant experiences, it is indeed a work of art and, more often, an
act of God. If the OP goes down that route, he may never actually get
his receiver built!

Looking at the websites of various manufacturers/suppliers (Google on
"crystal+frequency" and similar), it looks like you should be able to
get custom-made crystals in the required frequency range for less than
$20 each. I'm sure that at least the 5MHz will be available
off-the-shelf for less than $5 so we're talking maybe $100 for the six
crystals.

The alternative is, as has been suggested, a frequency synthesizer.
There are countless circuits available, but care should be taken to use
one where the spectral purity of the output signal is adequate for use
in a communications receiver. In particular, the phase noise has to be
low. One approach would to be look for a kit with a good spec (and
obviously something as simple as possible). A Google on
"frequency+synthesizer+kit" and similar brings up lots of information.
--
Ian