View Single Post
  #53   Report Post  
Old July 1st 07, 07:19 PM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
John Smith I John Smith I is offline
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 1,154
Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency

Don Bowey wrote:
[pure crap!]


"In the mid-1870s, a form of amplitude modulation—initially called
"undulatory currents"—was the first method to successfully produce
quality audio over telephone lines. Beginning with Reginald Fessenden's
audio demonstrations in the early 1900s, it was also the original method
used for audio radio transmissions, and remains in use by some forms of
radio communication—"AM" is often used to refer to the mediumwave
broadcast band (see AM radio)."

Taken from this URL: http://en.wikipedia.org/wiki/Amplitude_modulation

And, please read the WHOLE PAGE before making a larger idiot of yourself ...

JS