Hi Ron, This link may be helpful. It is a comparison of the Pro3 vs. the Pro2. http://www.nsarc.ca/hf/756p3_p2.pdf I have found that the NB on my Pro3 is very effective in dealing with repetitive impulse noise, especially in combination with the NR. Cheers for now, 73, Adam VA7OJ/AB4OJ Scanned for viruses by Blue Coat http://www.WinProxy.com/