On Sat, Apr 3, 2010 at 12:19 AM, John Coppens <john@jcoppens.com> wrote:
> With modulation modes proliferating (all those digital modes were too
> many to keep track of), FCC and, I suppose regulatory agencies of Canada
> and many other countries opted to specify maximum bandwidth allowed in
> certain frequency segments. So, in the more restricted shortwave bands
> you'll find 2.5 or 3 kHz as max bandwidth (typical SSB), while in higher
> bands wider modulation techniques are permitted.

Ah. Makes sense now.

> Note that appart from just the maximum bandwidth there still may be
> restrictions on the actual modes. And there is a restriction on the
> contents of the data transmitted, which much be compatible with the
> amateur charter. (and the data may not be transmitted encripted, except
> with publicly decodeable algorithms)

That's outrageous! Why such harsh restrictions?
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