The Russian Woodpecker
Those of us on HF 20m during the 70s and 80s will remember the woodpecker. Sometimes is was S9+20++, other times it was just a nuisance. After the fall of the Soviet Union information started to appear on the WWW and we were amazed at the massive system the Russians had assembled.
http://en.wikipedia.org/wiki/Russian_Woodpecker contains oodles of info, including an audio clip of its QRMing capability.
This is a screen-capture of one of the arrays.
(sorry 'bout the long URL) has dozens of great shots of the hardware. Here's one.
Info obtained from Google search on "russian woodpecker"