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Old June 30th 07, 07:44 AM posted to sci.electronics.basics,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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First recorded activity by RadioBanter: Jun 2006
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

On Jun 29, 10:10 pm, "Bob Myers" wrote:
"Radium" wrote in message

ps.com...

My basic question is if I have an AM receiver which receives signals
on a carrier frequency of Fc, is it mathematically-possible for me to
receive a modulator signal -- on that station -- of a frequency higher
than Fc? If not, then why? If not, then how are the submarines which
use ELFs [Extremely Low carrier Frequencies around 3 to 30 Hz] able to
perform voice communications?


I just stretched the question out to astronomical extremes. I have a
habit of doing that.


Why not simply ask the question you mean to ask, then, rather
than the absurd numbers you put in the original version of this
(and which you then expect everyone to work through, just to
see what the hell you might be talking about)?

The answer to the question you seem to be asking is obvious
if you simply work through the mathematics of what is going on
in amplitude modulation. So why not simply do that, and not
ask such incredibly obtuse questions?

One hint: the ELF submarine communications to which you refer
are NOT carrying voice communications, but very low-rate
CW ("Morse code," if you want to think of it that way) signalling.

Bob M.