Re: Sampling Theory question


"Phil Allison" <philallison@xxxxxxxxxx> wrote in message
news:5i74ceF3n6c6nU1@xxxxxxxxxxxxxxxxxxxxx
"Bob Masta"
I'm not sure what you mean about the carrier not changing in
amplitude. The energy in the spectrum at the carrier frequency
falls as the energy in the sidebands rises. (Otherwise, we'd have
a neat method of power generation!)
** Not at all.
An AM signal gains power as the modulation percentage is increases.
With square wave modulation of 100 % depth, the average power level
doubles - as the carrier is boosted to double voltage level for 50 % of
the time.
AM radio stations typically allow upwards modulation beyond 100 % making
the increase even more.

I wonder if Bob was talking about a balanced modulator which produces
DSB suppressed carrier, and not about DSB with full carrier which is the
stuff
of AM on the medium wave?

An easy mistake to make these days.


.

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