When I was looking into FM supercasters I came across some strange arcana relating to a terawatt broadcast. I made a note to come back to it, because obviously there had to be a story. A traditional broadcaster could NEVER rate in Terawatts, it would make peoples heads explode like in the movie scanners. http://www.naic.edu/
So I found it. In Arecibo, PR there was a natural disc-shaped hole in the rock. Inside this bowl we constructed the world's largest radio-telescope, with a diameter of 1000 feet. In 1974 we modified it, enabling it to broadcast signals at a power of up to 20 terawatts . NOTE:1 terawatt = 1 trillion watts.
So why the hell did we want to build a transmitter that big?
Because the nerds at SETI want to talk to aliens... http://www.seti.org
As an inaugural test of this array SETI transmited an encoded message and broadcast it out into space. The signal was directional toward the globular star cluster M13. It's about 25,000 light years away in the constellation of Hercules. The message was transmitted on 11/16/74 and consisted of 1679 pulses of binary code over three minutes. It was transmitted on 2380MHz. Woe be unto those who tried to listen terestially.
What was in the message? well that's not about radio at all so I stop here. but you are welcome to read more in gloriously geeky detail: http://www.cropcircleresearch.com/articles/arecibo.html