Since the middle of the 1970s, radio enthusiasts have been fascinated and perplexed by an odd buzzing signal that keeps repeating on the frequency of 4625 kHz. It has no known operator, no official ...

Cryptic messages have been broadcast on what has been dubbed "doomsday radio", a shortwave station in Russia that has been active since the Cold War. The mysterious radio station UVB-76, thought to be ...