I was first licensed in June 1953 as KN2EDH. Subsequent calls were W0PDL and N9EMU before ugrading to Extra with the call WO9S in January 1990. I enjoy DXing (#1 Honor Roll) and contesting (member of the Society of Midwest Contesters), including from the U. of Chicago club station, N9UC. I am a retired professor of physics at the University of Chicago, active in research and activities of the American Physical Society. My specialty is particle physics.