Greetings all Another couple of good sources of info for SDR and DSP based radios are: http://www.nitehawk.com/sm5bsz/linuxdsp/linrad.htm along with http://www.nitehawk.com/w3sz/index.htm For hardware do a google search on the variations of the KK7B RX/TX platforms which will provide the I/Q outputs to feed the dsp of your choice. 73 de Mike AA9IL