[BC] AM Stereo

[Kyle Magrill]

You have to ask how the test was conducted.  
Our group had two AM stereo stations.  One I 
put on the air in 1987 and the other was 
converted from Harris to Motorola.  I had a 
1986 Z28 with a factory Delco AM stereo 
radio.  Now, the AM stereo sounded fine 
on a $4,000 mod monitor in the studio, 
but paled considerably on my Delco radio.
As far as I can tell, it sounded similar on 
all of the AM Stereo receivers I tried.
I still have a Sangean SR-66 walkman
that I bought at an NAB show and it has
pretty good fidelity, but the FM still sounds
better.   In the end, it was the frequency 
response of AM that killed it, not the choice of
which stereo system was selected. Kahn or Motorola, 
Two channels of 4kHz audio is just 2x as bad as one.
  
And for the record, I never thought that the NRSC 
did AM any favors by forcing the spectrum to 10kHz.
I demonstrated that, despite the mediocre bandwidth
of my Delco radio, audio in the range of 10-15kHz was
still present in the output.  When we switched in the 
10kHz brick wall, the loss of quality was subtle but noticable.
A better approach might have been to require a 10kHz 
filter only in cases of demonstrated interference to 
adjacent channels. 

###############You Wrote

Bill, at first it might seem that way,
        but several studies in that era 
        (including one a U of Windsor?)
        established that if the same cut
        were played on AM stereo and
        FM stereo, the average listener
        preferred the AM stereo