|A Word or Two about using Modulation for AM broadcasting:
Always keep the Pulse Width of the modulation between
> 50% & < 100%;
> 00% & < 50%.
At first blush, the reasoning for this
may not be obvious: A transmitter is not broadcasting a varying voltage
but a varying POWER. That is, the varying modulation voltage is controlling
how much Carrier POWER is transmitted. Although the modulating voltage
may have a polarity +/-, the RF power leaving the antenna has no polarity.
At the receiver the varying power is demodulated/ which is saying
it is converted from a varying power to a varying voltage, and if you "AC
Couple" the detector's output you again have a varying voltage that has
a +/- polarity. --Huh?
NOW! At this point you should not have
experienced an "Ah Ha!" --yet.
YOU are about to Experience a Genuine --or your money back.
we will need a
Notice anything Funny? Right, the second harmonic of the modulation
signal increases if the [ > 50%, < 50%
] rule is violated!