View Single Post
  #248   Report Post  
Old July 14th 07, 07:14 AM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
Brenda Ann Brenda Ann is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 855
Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency


"Ron Baker, Pluralitas!" wrote in message
...
|
| "Rich Grise" wrote in message
| news | On Wed, 11 Jul 2007 22:52:17 -0700, Jeff Liebermann wrote:
|
| "NotMe" hath wroth:
|
| (Please learn to trim quotations)
|
| Actually the human ear can detect a beat note down to a few cycles.
|
| If you are talking about the beat between two close
| audio frequencies then one can easily hear a beat way
| below 1 Hz.


But what you hear below ~20 Hz is not the beat note, but changes in sound
pressure (volume) as the mixing product goes in and out of phase. This
actually becomes easier to hear as you near zero beat.