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Old July 7th 07, 06:47 AM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
Roy Lewallen Roy Lewallen is offline
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Default AM electromagnetic waves: 20 KHz modulationfrequencyonanastronomically-lowcarrier frequency

isw wrote:
In article ,
Roy Lewallen wrote:
. . .
DSB stands for Double SideBand. Although I suppose an FM signal could be
called DSB because it has two *sets* of sidebands


Um, actually, it has a lot more than that. A carrier FM modulated by a
single sine wave has an infinite number of sidebands. If the modulating
signal is more complex, then things get really complicated.


Sometimes it's difficult to communicate. A "set" can consist of more
than one. In the case of FM, each set includes an infinite number,
although only a limited number contain a significant amount of energy.
The remainder can be ignored without any substantial degradation of
received signal quality. This is true regardless of the complexity of
the modulating signal.

Roy Lewallen, W7EL