bob wrote:

Okay, so if it's several hundred times per minute, that would definitely
change everything. However, if that's the case, would it not be most
likely they're employing some sort of sinewave (or sawtooth, or
stepwave) 'seed' signal into a VCO which supplies the mixer freq?

Both seems to be in use, depending on the manufacturer.

Check out those sites:

www.transcrypt.com
www.kavitsecure.com
http://www.daxonfil.com/en/index.html

It's not impossible, but it may be unlikely the mixer freq changes that
often.

It is not too unlikely - anything else would decrease the security too
much.

The more I think about it, it could be a nasty chore to straighten it
out. Harris has a system for HF that's straight analog but certainly not
easy to decipher, but their's is not straight inversion either. If
however, the mixer truly shifts about that much, it's simply not worth
the effort, unless you don't mind placing your sanity at risk...

*g*





regards - Ralph

--

Want to get in touch? http://www.radio-link.net/whereisralph.txt