Duga 3 the Russian Woodpecker
Duga-1 Russian: Дуга-1 (NATO reporting name Steel Yard) was a Soviet over-the-horizon (OTH) radar system used as part of the Soviet ABM early-warning network. The system operated from July 1976 to December 1989. Two Duga-1 radars were deployed, one near Chernobyl and Chernihiv, the other in eastern Siberia
The Duga-1 systems were extremely powerful, over 10 MW in some cases, and broadcast in the shortwave radio bands. They appeared without warning, sounding like a sharp, repetitive tapping noise at 10 Hz, which led to it being nicknamed by shortwave listeners the Russian Woodpecker.