Surfin': Remembering the Woodpecker
If you were an active ham radio operator or shortwave listener between 1976 and 1989, you probably remember a rather nasty form of interference on the HF bands during that era known as the "Russian Woodpecker." Its name came about because triangulation indicated that it originated in the west end of the USSR and its signature tapping sounded like a woodpecker pecking at wood.
Its real name was Duga-3 and it served as over-the-horizon radar for the USSR's anti-ballistic missile early warning system. With an estimated transmission power of 10 MW EIRP, the Russian Woodpecker played havoc on the HF bands.
To combat the Woodpecker, some hams attempted -- according to Wikipedia -- "to 'jam' the signal by transmitting synchronized unmodulated continuous wave signals, at the same pulse rate as the offending signal. This idea was considered, but abandoned as impractical. Simple CW pulses didn't appear to have any effect. However, playing back recordings of the woodpecker transmissions sometimes caused the woodpecker transmissions to shift frequency leading to speculation that the receiving stations were able to differentiate between the 'signature' waveform of the woodpecker transmissions and a simple pulsed carrier."
The Woodpecker disappeared in 1989. Its demise was probably due to the end of the Cold War, the end of the USSR and new satellite early-warning systems.
Everything2 and Wikipedia have interesting and contradictory (from a ham radio perspective) entries about the Woodpecker. The Wikipedia entry includes a sound file of the Woodpecker interfering with WWVH in 1984.
It is an interesting piece of radio history, but what rekindled my interest in the Russian Woodpecker is the spate of photographs of the Duga-3 antenna farm that I have encountered on the Internet recently. Your mileage may vary, but I believe one of the best collections of photographs is on the English Russia Web site.
By the way, the antenna farm is inside the 30 km Chernobyl Zone of Alienation. For some eerie photos from the Chernobyl Zone, including more photos of the Duga-3 antenna farm, visit the Pripyat Project Web site.
Until next time, keep on surfin'!
Stan Horzepa, WA1LOU