Thread: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
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Old June 30th 07, 09:38 PM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
Don Bowey Don Bowey is offline
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Default AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
On 6/30/07 12:46 PM, in article
, "Radium"
wrote:

On Jun 30, 3:32 am, "Mike Kaliski" wrote:

It is not possible to modulate a carrier frequency at a frequency higher
than the carrier frequency.

Why not?

I am getting conflicting answers. Some say it's possible to modulate a
carrier frequency at a frequency higher than the carrier frequency,
others say it isn't.

Partly it's because you formulate **** poor questions.


Who is right?


Neither if stated as an "absolute rule," a.k.a. a Universal Generalization.
It depends on what you want as a result. However, IMHO opinion, I believe
it is best to have the Carrier at a higher frequency than the modulating
frequency.

If you are amplitude modulating a Carrier with a voice band signal, then it
is mandatory, for a reasonable result, that the Carrier have a much higher
frequency than the modulating frequency.

If you are AM modulating (a.k.a. RF mixing or converting) two signals for
the purpose of creating sum and difference "Carriers" in, for example, a
synthesizer, you could use the low frequency to "modulate" the high
frequency frequency, but I donšt recommend it unless some special effect is
desired.


Start with the question of what is it you wish to accomplish then ask real
questions, not some far-out hypothetical drivel.




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