This afternoon, I was checking my watch and library wall clock with universal time broadcast by the National Institute of Standards and Technology (NIST) shortwave station WWV when a familiar signal emerged.
The 10 MHz frequency is usually where I find WWV’s strongest signal, which was also the general frequency area where I often heard the so-called Russian Woodpecker, or Duga, during the 1980s. I was surprised to hear something much like that Cold War signal at its old frequency. Today’s signal didn’t sound exactly the same, but close enough to inspire a little old radio nostalgia.
What’s a Duga?
The Duga was a Soviet over-the-horizon (OTH) distant early warning radar network, first detected and christened ‘Woodpecker’ in 1976. Until it ceased in 1989, the officially unclaimed signal was well-known to NATO as an OTH system, as well among amateur radio enthusiasts, myself included – although I wasn’t aware of its origin until well after the Cold War ended.
Generally considered a nuisance signal, it interfered with legitimate broadcasts, oceanic aviation communications, utility transmissions and amateur radio broadcasts. While not a consistent broadcast, its frequency drift could completely obscure the closer WWV signal at times.
The Duga-1’s imposing antenna arrays – a transmitter and receiver, are located just kilometers from the Chernobyl Nuclear Power Plant, north of Kiev, Ukraine. Another Duga complex – Duga-2, of course, was deployed in the far east near Khabarovsk Krai.
Here’s a recording of the original signal…