Hi Win, In the Pro3, the DSP *is* the radio. http://www.qsl.net/ab4oj/icom/pro_dsp.html http://www.nsarc.ca/hf/hf_min022306.pdf Cheers for now, 73, Adam VA7OJ/AB4OJ Scanned for viruses by Blue Coat http://www.WinProxy.com/