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AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
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July 1st 07, 05:48 AM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
Don Bowey
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AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
On 6/30/07 9:01 PM, in article
, "Radium"
wrote:
On Jun 30, 12:55 pm, John Smith I wrote:
Use simple logic, you can modulate a dc (0 Hz) with higher freq (voice),
(hint, your telephone line is an example) right?
The telephone does not use either AM or FM. It is simply the
electrical equivalent of the sound that gets into the microphone. You
input a 1 KHz tone into the microphone, telephone lines will carry a 1
KHz AC current to the destination. The louder the sound into the
microphone, the stronger the amperage in the telephone lines.
Good for you for catching that one. The effect of microphone current has
noting at all to do with AM.
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