Re: geography nerds?

mike weber <fair****tfan@[EMAIL PROTECTED]
> wrote:
> Don't even need a tuned circuit; ...

True, but then you'll hear all AM stations at once.  This may be
practical if there's one station that's much stronger or closer
than any other, and if that happens to be the station you want to
listen to.

A hundred years ago, tuning didn't work very well, either for
transmitters or receivers.  Transmitters tended to transmit over a
wide range of frequencies, and receivers tended to receive over a
equally wide range of frequencies.  So what people did was impose
varying *audio* frequencies on their Morse code, by selecting the
speed at which a wheel studded with spark gaps rotated.  Then
listeners would mentally focus on one pitch, and mentally tune
out all higher and lower pitched signals.
-- 
Keith F. Lynch - http://keithlynch.net/
Please see http://keithlynch.net/email.html
before emailing me.