This is a fascinating link which is prompting me to ask, when did they start broadcasting in FM stereo without simulcast? My father has some cassettes that he made off the radio in 1970 and the WMMR station ID announces the station as being in stereo. The tapes are in mono since although recorded on a stereo cassette deck (a Concord F-400) he was using a monaural Bang and Olufsen portable. I assume in 1970, FM in stereo was fairly new at the time. I work for a company that supplies restoration parts for old Mustangs and I know that in 1966 you could get a mono AM/FM radio or a AM radio with stereo tape (8-track) and their was still an option for a reverb unit. I assumed that in 1966 their was no FM stereo or it was still in its infancy. If anyone has an answer, this has been one I have been trying to figure out for awhile (as I was not around back then).