[BC] Wow, I wonder if y ou feel the same way about AM?

[Dana Puopolo]

No, that isn't true! Look at the U.S. and Canadian schemes where the spacing
is 10 kHz. In the 1970's, many if not most AM stations had a frequency
response out to 15 kHz. They did so by simply going into the adjacent channel.
The FCC allocates stations with this in mind; the closet spaced stations
you're likely to find in a market are spaced by 20 kHz.
Even today, NRSC allows for a 10 kHz audio bandwidth-which means if you are
licsnsed on 1500 your bandwidth actually goes from 1490-1510. The only
difference with stations 9 kHz spaced is the hetrodynes are 9 kHz, not ten. If
you listen to foreigh AM, it DOES sound better then the crud we put on AM
here-because anyone that uses IBOC on AM MUST chop their audio off steeply at
5 kHz-making their audio on air sound like the old ABC T carrier networks
did-complete with the hiss down 25 db!

-D

From: "Dan Dickey" <dldickey at verizon.net>

Um, I don't think the foregoing is accurate in most of the rest of the 
world. In a 9kHz grid allotment scheme each station will usually be required 
to use a 4.5kHz brick-wall filter on their audio chain. AM in the rest of 
the world has a lot less bandwidth than here in the US.

Regards,
Dan