In the late 70's, the FCC mandated that FM stations quit simulcasting their AM programming (except for morning drive, for a few years to allow for transistion IIRC). At the time, I was working in Top40 radio in Minnesota. I seem to remember a Trade mag story about KIIS at the time that goes as follows: The AM/FM combo was getting solid numbers as a top40 and not wanting to break up the success, the FM station rain the exact same playlist, but 15 minutes later than the AM and with different jocks. I may have everything including stations confused, but if anyone can fill in more info about that stunt (even if it occured in another market), please fill me in.