What is the waveform of radio frequencies? I thought they were sinusoidal; am I wrong?
I started to wonder about radio frequency waves at the time (two years ago), if they were digital, because all systems are digital, but the problem was that radios were being used in World Wars I and II, and even before. At that time, electronic devices were analog. So it can only be a sine but again, how can it be a sine wave when I know that electricity in my home is AC?