The AM Forum

This gigantic antenna system called Duga-3 is located near Prypiat in the Chernobyl area.  It was built in the 70's as an early missile detection system (over-the-horizon radar system). It was also called the Steel Yard hence its distinctive appearance. The antenna was deactivated in 1989.

The Russian Woodpecker was a notorious Soviet signal that could be heard on the shortwave radio bands worldwide between July 1976 and December 1989. It sounded like a sharp, repetitive tapping noise, at 10 Hz, giving rise to the "Woodpecker" name. The random frequency disrupted legitimate broadcast, amateur radio, and utility transmissions and resulted in thousands of complaints by many countries worldwide.

Starting in 1976 a new and powerful radio signal was detected worldwide, and quickly dubbed the Woodpecker by amateur radio operators. Transmission power on some woodpecker transmitters was estimated to be as high as 10 MW EIRP. As well as disrupting shortwave amateur radio and broadcasting it could sometimes be heard over telephone circuits due to the strength of the signals. This led to a thriving industry of "Woodpecker filters" and noise blankers.

http://www.artificialowl.net/2008/12/abandoned-giant-duga-3-system-antenna.html

F117A was a fine woodpecker blanker

Wow, what a system. Looks like these phased broad-band dipoles were fed with openwire.  Probably a Sterba design of some kind.

It's always amazed me what a large group of people can accomplish. It takes designers with big ideas and workers with BA's to carry it out.     One man would be too fearful to pull it off, whereas a large group pulls together and makes it happen. 

The incredible size and scope of this project shows the serious effort the Russian military went to back in the cold war days.

T

If it's like what is used by some shortwave broadcasters (and it looks like it is) those are stacked/phased dipoles with a reflector screen. The beam can be slewed or steered by varing the phasing. Since they are fed with open wire, the system can work over at least a 2:1 frequency range. The cage design increases bandwidth and power handling capability.

VOA had a number of similar looking arrays. I think most of them are gone.

HARRP

I worked with an old B17 driver who claimed we would spend the USSR into the ground.

That would be an interesting site for a DXpedition.  Imagine loading 1 KW of AM into that thing on 20m (one of the commonly used frequencies for the Woodpecker in the 70's).  You could most likely blow slopbuckets off the band all over North America.

One minor problem might keep a sensible person away, though.  Check out the site to see precisely where the array is located.

Don,
Thanks for the post.............its VERY interesting......
Bill

Kinda like when the Tron fired his mobile rig into the big rhombic array at the shortwave BC station in Kentucky. LOUD!

Castle Bravo pictures pretty impressive. I guess Dr. Teller had a bit of a math error. My OM got out of the Navy in '52. They wanted him to stay in and go to the the test area.

Steve said:
I remember that!!

Yea, he was using my second kw match box on its way to Bill's. I'm still kicking myself for selling it.

Looks to be a popular search at Google


http://maps.google.com/maps?f=q&hl=en&geocode=&q=prypiat,+antenna&sll=51.300569,30.060825&sspn=0.050766,0.109863&ie=UTF8&ei=xNJKSdKrMoyENurvqP4M&cd=1&cid=51305466,30065739,4109646118345347283&li=lmd&ll=51.317095,30.065718&spn=0.026662,0.054932&z=14&iwloc=A


I looked at this about a year ago and was amazed at the Cherynobyl area. Lotsa rust

Take a look at the Google and switch to satellite photo view and pan to the left (southwest) of the two arrays. See how the access road ends up in a big circle about a mile away? Boy that sure looks like it is the right size fior a wide aperture HFDF array. This would be how you would determine where the signal is coming from that you want to track or jam.

Oh and for fun do a great circle of the broadside and guess where the array is aimed.

My great uncle Jerry, WA1JTE was there.

Those still around got a huge settlement from Uncle Sam in a class-action suit just a few years ago.

On a whim, he went looking online one day for his old shipmates. When he found them, they told him about the suit, and he got in on it just in time. I think they were awarded around $70k per.

They earned every penny, too. A lot of those boys absorbed some ungodly energy from the beta blast.

Jerry's about 89 now, and still going strong last I talked to him. He was one of the lucky ones.

I remember my mother telling us to stop eating snow when the above ground tests were going on out west. I think it was the late '50s.

Imagine learning of the F117A after spending all that money on the woodpecker.

I remember seeing somewhere that they used seperate receive sites so that the transmitter wouldn't overload the receiver. And there's still people that go into that area, including workers at the reactor itself.
I also saw somwhere that there are some hams that do have antennas mounted on the towers at the radar site, but I don't khow if that's true. There were two Duga-3 sites, this one and then another one in eastern Russia. Of course, they were both aimed at the US.
Shelby KB3OUK

I also noticed that when I looked at the satellite map, it apears that there are two sperate antenna systems at the site, one with shorter looking towers and that isn't as long, and the second one which has taller looking towers and is longer in lenght.