There’s a big reason those enormous AM radio transmitter towers are surrounded in fences: touching them can be incredibly dangerous on account of the enormous amounts of power pushed through them.
A video on Facebook by the Michigan State University Amateur Radio Club shows what happens if you short out one of these towers using a car’s jumper cable: you can hear the radio station in the electricity arc.
This happens because AM radio’s signal is adjusted up and down dynamically to indicate the highs and lows of sound waves. If you cause a gap in the power line to the antenna the electricity sparks, causing lightning and burning the air around it, in which the current goes up and down in intensity — just like the signal itself — causing the sound to occur.
It isn’t the first time something like this has been done. A video uploaded to YouTube in 2012 shows Russian kids putting plants on an AM radio tower and listening to the radio through them, causing a short in much the same way.
Doing this is incredibly dangerous, as it can cause internal RF burns as the current travels through the body, so maybe don’t try it on your neighborhood’s transmitter.
Still, the Facebook video is an incredible demonstration of just how much current is flowing through these antennas.
➤ Michigan State University Amateur Radio Club [Facebook]