[BC] FM for IBOC?

[Stanley Adams]

I believe that the author of that article is arguing from a lot of
mis-information.  While he establishes the idea of the baseband in FM; he
totally misunderstands the concept of the bandwidth and the carriers that
are added.  What he is missing is all of the things that make up the true
baseband and fidelity, which is the modulation index and the deviation of
each of the channels that would be grouped on the FM baseband.  If you have
ever noticed that mono-FM is superior to stereo-FM in mobile coverage, it is
because about 90% of all the power devoted to the FM baseband is taken up by
the mono signal.  What the author would be proposing would be a bunch of
little channels that would have performance as bad or worse than the SCA
channels, and many on this list know how limited in performance those
channels are.  

In addition, while FM is a quality service, and it would have been great if
TV visual would have been FM instead of AM, it is still analog and therefore
subject to all of the anomalies of analog transmission; phase distortion,
IMD, even motor generated noise, multi-path and the like.  Digital will also
have quite a few anomalies of its' own, many of which the current HD people
are not readily talking about.  But as a given whole, digital will be able
to deliver the transmitted signal with fewer demodulated audio artifacts
(hopefully :) ) then doing it the old FM way.  

So, if I am not mis-understanding the article as written then these are the
reasons it will not work.

Thanks

Stanley Adams
Memphis