I recently came across an interesting article from an NAB (National
Association of Broadcasters) newsletter called "Radio TechCheck". The
article is entitled "NPR Evaluating Low Bit Radio Audio Codecs For
IBOC". You can retreive the article yourself at:

www.nab.org/scitech/techcheck/radio/rd071904.pdf

What bothers me is that this article suggest that the FM Hybrid IBOC
signal be extended beyond its current bandwith to accommodate additional
voice or data services. The diagram in this article shows the extended
hybrid portion of the IBOC signal overlapping with the current FM analog
signal. I cannot see how this could be done with some degradation to
the FM analog signal.

I'm all for new technological developments in radio but not if they
interfere with existing technology. Does anyone have further
information regarding "Extended Hybrid IBOC"?

Chris