Just wanted to jump in here and say "THANKS" for helping me to solve a radio mystery! On the NPR quiz show, "Wait, Wait, Don't Tell Me!" -- which originates from WBEZ in Chicago -- the program introduction features some strange radio whistling noises (which sound like they're coming from an old super-regenerative receiver!), and then the letters "EBCD" sent in Morse Code at about 8 wpm. I had absolutely no clue what "EBCD" stood for, so I Googled it, and I was immediately directed to your site. I now understand that "EBCD" was a punch card (or perhaps a punch tape?) coding format used to drive early-generation computers or teleprinters. As to why WBEZ is using "EBCD" as a baffling Morse Code introduction to their quiz program, I have absolutely no clue. But I'm glad the mystery has been solved anyway!
TNX es VY 73! (de KB1F)