Shortwave radio has a reputation of being a good source of squelches, static, snippets of audio from all over the world, and other sorts of real-world, long-distance radio wave sound effects. Radio wave phenomena such as whistlers, tweaks, and swishes can also purportedly be picked up via shortwave. There are many kinds of shortwave radio, from HAM/Amateur radios that costs hundreds of dollars (minus antennae!), to hand-cranked emergency radios.
Does anyone have experience using shortwave radio as a sound source, and if so, what kinds of hardware did you use to record interesting effects from the real airwaves?