[BC] AM Stereo

[Kyle Magrill]

That's the point.  It's fidelity not the number of channels that matters.  
If AM sounded as good as FM, it could comptete, even if it was mono.  

Now, as to the issue of good sounding AM receivers, I agree that it was
possible to build a good one at any point along the broadcast timeline.  
My point was that it cost more to do that which is bad if the market trend 
is to make cheaper radios.
                                   
In fact, simple crystal sets are quite hi-fi.   But they lack both sensitivity 
and selectivity.  Getting good audio performance while keeping the sensitivity 
and selectivity added cost.   Starting with the first pocket transistor radios of 
the 1950s, the push was on to build cheaper radios, not bettter ones.   When 
FM became a desirable addition to radios, it could be added cheaply and still
sound good, whereas AM used tight IFs to get the sensitivity and selectivity up.  
If the IFs are loose, then more stages are required leading to higher manufacturing 
costs.  

Today, the story could be different.  The advent of DSP based radios means 
stuff  that was expensive a few years ago can be done cheaply and better in
software, but again, the genie has, long ago, escaped the bottle.

#############You Wrote:

...... Just go ahead and run
        L+R on both channels.  Most listeners will not
        even notice.

>The technology of the day made it expensive to build a hi-fi AM system, but even the cheapest of FM radios could sound good, so AM's undoing was partly a combination of lack of available, low cost,  technology and starting much too late in the game. 

        Well, there was this strange little fellow who introduced me
        to his 1950 Ford sedan and its radio. He clipped a couple
        of caps and it was flat to 15 kHz. (This was before the
        pre-emphasis wars.)  You could not tell the difference
        between AM and FM.