[78-L] stereo, ca. 1932

[Michael Shoshani]

On Wed, 2009-07-08 at 10:43 -0400, David Weiner wrote:

> 
> I distinctly remember an NBC Perry Como show, probably in 1959, that was
> broadcast in stereo - they told viewers to put an AM radio tuned to WNBC New
> York some distance from the TV set to hear the stereo spread. 

I'm curious as to how they pulled that off, considering that the country
wasn't blanketed with NBC O&O radio stations carrying that other
channel. I'm assuming that this was done the same way FM stereo is done,
ie sum-and-difference matrixing. 

As with M-S stereo recording, in FM stereo one channel carries the sum
of both left and right - essentially the mono signal - while the other
channel carries the difference between the two, or what is either on the
left or right but not common to both.  

The sum could be broadcast over the television network, thus not
depriving the national audience of anything important, while the
difference could have gone out over radio to provide that extra spacious
three-dimensional stereophonic space-age sound.

I hope Mike Biel is reading this, because if I have something screwed up
somewhere I would very much like to be corrected. 

MS