Bob Bruhns wrote:
Indeed, 'tis a puzzlement. I can draw three continuous sine waves of
apppropriate amplitude, frequency and phase, corresponding to carrier, upper
sideband and lower sideband, and I can add them point by point, and I can
duplicate a 100% modulated AM signal waveform as we understand it. I have
to believe that this works backwards; if I make this waveform by modulating
a carrier in an AM transmitter, then I am synthesizing the same continuous
sine waves.
Hi Bob,
The three sin waves look like what is happening but in reality the am
signal is not produced by adding sin waves. It is produced by
multiplying them. It just happens that when you add them you come out
with the same result so it appears that they are added.
And to keep things simple that is how it has been taught over the years
as another poster mentioned.
73
Gary K4FMX