Hi Paul

The idea behind DSP is actually pretty simple. Its just that there is
lots of maths involved (ie repetitive). You need an A/D, a number
crunching processing and a D/A.. thats it! there are even direct DSP
demodulator devices available for HF receiving. Analog Devices does them
(amongst others)

If you are looking for a PC based device to filter (say) for CW use you
might want to look at Linrad. Its a Linux application but the web info
is well worth a read. Spectrum Lab for W32 also has some DSP based
filtering but I havent tried it.

There are quite a few amateur based DSP projects out there. I think the
ARRL may have even supported a homebrew project for a while. If you
still cant find it on a websearch get back to me and I'll have a deeper
look.

Sorry I cant help more.

Cheers Bob VK2YQA

Paul Proefrock wrote:
Does anyone know of a site or info to build a DSP speaker similar to the
Hear It by Gap Antenna?