The Russian Woodpecker, the Duga-3, is a soviet radar system located in Ukraine that operated from July 1976 to December 1989. The powerful radio signal it created was detected simultaneously worldwide, and quickly dubbed the Woodpecker by amateur radio operators (usually 10Hz). It’s not well known why the Duga was builded, but it costed about 7000 millions russian rubles (2 times more expensive than the Chernobyl plant). The ukrainian Fedor Alexandrovich’s research into the cause of the Chernobyl disaster and its potential connection to the Duga (they are separated only 9 kms between them) seems really interesting. Link to the Russian Woodpecker documentary trailer: https://www.youtube.com/watch?v=9rd4ARsbg_0