Hi!
Thought some list members might enjoy a trip down Memory Lane, back to 1979 in fact.
Back at that time the FCC were looking at 5 different transmission methods for the proposed introduction of Stereo AM.
The link below is to a demo record released by Harris Labs of their method.
In Australia the ABC did tests of the 5 methods in late 1984 though the ABC themselves didn’t officially start broadcasting in Stereo AM until 1986 - more than a year after the official launch of Stereo AM in Australia -.
Enjoy!

https://www.youtube.com/watch?v=2E9SntO4Ul8

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Those of a positive and enquiring frame of mind will leave the rest of the halfwits in this world behind.