I read once that AM radio in the US was allowed up to 15 KHz, but the NRSC standard, adopted
by the FCC, calls for a limit of 10 KHz. THat's only about a half octave from the 15 KHz
limit of FM, and sounds pretty OK, certainly better than rendered by most AM radios.

--
Regards from Virginia Beach,

Earl Kiosterud
www.smokeylake.com

Note: Top-posting has been the norm here.
Some folks prefer bottom-posting.
But if you bottom-post to a reply that's
already top-posted, the thread gets messy.
When in Rome...
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"SFTV_troy" wrote in message
ups.com...

Earl Kiosterud wrote:

I think the USB to which Tom refers is upper sideband. Converting AM stations would mean
they'd transmit only one set of sidebands, the upper set, reducing the bandwidth to
almost
half. More stations could be licensed in the same band. ...


But still have the same poor AM sound. Digital offers an upgrade to
near-FM quality.

As a side issue, the loss of fidelity for which AM is notorious is largely in the
receivers,
with their narrow bandwidths, resulting in audio that is rolling off pretty fast around
the
5 KHz point. (AM stations actually transmit a fairly high-fidelity signal.)

How high? 0-10000 hertz? That's not as good as the 0-15000 possible
with AAC+SBR.