You may want to have a look at
http://www.nitehawk.com/sm5bsz/linuxdsp/linrad.htm

This is the Linrad home page
Take the output of your Rx and feed it to the computer sound card.
You will have to do a bit of work getting up to speed on Linux if you
are not already familiar. However, the newer Linux distributions are
becoming better than Windows in terms of usability, in my opinion. The
program itself also takes some work to set up. However, you can use a
relatively low power computer eg 400 MHz PII, which are available
cheaply now as your DSP platform.
This is a very sophisticated package which is designed originally for
144 MHz EME.
If you really want to get into it, you could build the hardware as well

Richard

Adrina wrote:
Does anyone know of a source that either sells plans for or kit to build
a dsp for amatuer radio?. Specifically , I would like to use it in
conjunction with a shortwave receiver. If so, would you please post the
information. TIA.