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Old July 14th 07, 01:00 PM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
John Fields John Fields is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 58
Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

On Sat, 14 Jul 2007 15:14:28 +0900, "Brenda Ann"
wrote:


"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.


---
It's not a mixing product, it's a sum. Actually, the vector
_addition_ of two signals varying in phase.

Other than that, Bingo!!!


--
JF