"Frank Dresser" wrote in message
...

By the time in the early 80's when a standard, CQuam, arrose, AM was no
longer a music medium and had less than 40% of all listening.

But there were still people listening to music on AM, probably more than
are
listening to HD radio right now. I can understand the enthusiasm people
had
for AM stereo back then.

AM stereo might have kept radio as we then knew it alive.

By the time the Motorola system became the standard, AM station owners were
mostly concerned with finding a way to program their AMs so as to stop
losing audience. That meant an alternative to anything being done on FM.

Add to that the urban sprawl of American cities, which were growing out of
the coverage areas of most of the stations licenced to them. So few AM
stations could compete with the coverage and quality of the better FM
allocations that they were forced to do niche formats, religion, gospel (now
a big FM format in many markets) and ethnic formats.

When you consider that in the top 100 markets, there is an average of only
two viable AM signals, you can understand that a number of factors came
together in a three decade long perfect storm that has left AM with as
little as 9% to 10% of listening in rated markets (Houston 12%, but less
than 5% under 45 years of age is a good big market example).


Untrue. FM Stereo was introduced in about 1961, and the decade before
had
seen total FM stations go from over 1000 in 1950 to around 500 in 1960.

I didn't mean FM radio stations. I meant FM recievers. When FM began
it's
turnaround around 1970 or so, most of the FM receivers were mono.

Most of FM listening is mono even today. Few clock radios, kitchen radios,
desk radios, shop radios are stereo. And the effects of noise make in care
stereo minimal at most driving speeds.

The dominance of FM stereo receivers didn't happen until the price
difference was small.

FM did not start gaining on AM because of stereo. It was because the FCC, in
'67, mandated an end to simulcasting and many new format options came on the
air. But it took a full decade for FM to achieve listening parity... which
is why we say that HD is a long, long term process. And it is way to late to
save AM now that owners are moving the "good" formats to FM because the AM
listener base is so old they can't sell advertising.