FM Radio Transmitter

At a HAM radio store, like the HAM Radio Outlet chain of stores. You need a license (either HAM or commercial, depending on the band), in order to transmit with any power that will let you get farther than about 20 meters.

 

Well, NASA sends signals pretty far, eh? For more terrestrial applications, on the lower frequency bands (like 20m, 40m, 80m), HAMs routinely talk all around the world using skip off the ionosphere. This skip varies with the time of day, and the solar sunspot cycle. With good skip, you can run only a few hundred watts of power and talk to the other side of the planet.

Check out the links in my footer if you have interest in Amateur Radio. It's used for several important and some fun things.

 

(restoring post after the PF crash and restore)

Just to follow up on this thread. mikex24 and I had a lengthy conversation via PM. It turns out he is looking for a way to establish a radio comm link between two remote locations that are about 10km apart. One complication is that there is a hill in the way. I offered solutions like using lower frequency comm to bend around/over the hill, or placing a repeater on top of the hill. I was able to give him the website contact for his local HAM radio club -- they should be able to help him look at the options and figure out the best way to set it all up.