Hi Bill, Last Thursday, May 1, I gave the second presentation in my series on German WW2 radio technology at our local amateur radio club. The title of the talk is "German WW2 SIGINT/COMINT". Here is the link to the PDF: http://www.nsarc.ca/hf/german_sigint.pdf Cheers for now, 73, Adam VA7OJ/AB4OJ