# The WOODPECKER



## hawkey01 (Mar 15, 2006)

This link was received from ex colleagues of mine today. It shows the immense aerial array which caused the Woodpecker signal on HF which drove us all mad for years. 

http://www.artificialowl.net:80/2008/12/abandoned-giant-duga-3-system-antenna.html
(MAD) 
Hawkey01(==D)


----------



## treeve (Nov 15, 2005)

I remember that ... a Real Golden Oldie ... any data on size and power, etc? There were occasions when the signal piled in on MW and LW, but maybe they were other transmitters? I presume it did what it was intended to do, invade and irritate the airwaves.


----------



## hawkey01 (Mar 15, 2006)

Treeve,

Info on this system was of course top secret at the time - I am sure that there were departments in UK who had the technical info. We used to constantly make reports to Baldock about the interference. Needless to say it never did any good. I do understand that this type of system would require immense power. There is a mention under one of the photos that it was reputed to have a power of 10 Megawatts - EIRP - sorry I cannot remember what the definition of EIRP is - I am sure someone will come up with the answer. Something radiated power? Just to give some idea of the power our transmitters at GKA were 10 Kw.

Hawkey01


----------



## Ian (Mar 27, 2004)

If I remember correctly (and there's no guarantee of that these days), it was part of the Soviet Union's early warning system. Over the horizon radar. At times it could easily cover the whole H/F spectrum.


----------



## K urgess (Aug 14, 2006)

Is that Envelope Indicated Radiated Power?
The grey cells are twitching. (Whaaa)


----------



## treeve (Nov 15, 2005)

It was stated to have been simply a part of the early warning system at the time, but it seemed to me to have been a lot more than that, it was said at the time that it would have had to have had massive power. I'll have to have a dig out of my old SWL folders. I have a vague recollection of a form of EMP test being undertaken at the time, but by whom?


----------



## Ian (Mar 27, 2004)

Effective isotropically-radiated power (EIRP)??? Just found on Google.


----------



## BobClay (Dec 14, 2007)

Much to my shame, I must admit a sin. There were many times, particularly in the far east and Pacific, when the woodpecker caused me a great deal of frustration on HF.

So, being in possession of a Samson electronic keyer, I would set the dot sending paddle, to about the same repetitive frequency (10 hz sounds about right) and transmit on the strongest band I could find the woodpecker on. Varying the dot frequency from the key up and down so as to improve the chances of causing him interference. I know it's petty, it's bloody petty. But as I'm sure you all know, when you're a sparky, trying to take traffic from GKA at these distances, traffic that might be anything from ships orders to a 'happy birthday' for the 3rd Engineer, silly cold war war games transmissions tend to me very annoying.

I'm ashamed of it now ..... cos it made me no better than they are. 

I'm also sure I didn't accomplish anything by it... but it made me feel better.

I'd probably do it again in similar cir***stances.


----------



## treeve (Nov 15, 2005)

I should not worry about it at all .. we all fall into making personal strong objections and poking fingers in eyes, and we do it in the full knowledge that no one will take a blind bit of notice, and nothing will be done about it; but inside we feel the better for it, and in the way in which we have devised and enacted our protest, and often the manner in which we have performed our little technical feat, we pat ourselves on the back, because we know we deserve it. It is Life. We are Alive. We Care. That is the Real Stuff.


----------



## Vital Sparks (Sep 19, 2007)

I remember being told that you could get rid of the woodpecker by transmitting back using the same prf. It would allegedly detect this interference and automatically shift frequency. I tried it a few times but it never worked.


----------



## Andy (Jan 25, 2004)

BA204259 said:


> If I remember correctly (and there's no guarantee of that these days), it was part of the Soviet Union's early warning system. Over the horizon radar. At times it could easily cover the whole H/F spectrum.


Yep, I remember it as just being a huge OHR system. I seem to remember various filters (woodpecker notches) being sold in the 80's to help.
China seems to be bashing out some strong HF grief these days for similar purposes. And having said that, 17m gets knocked out by a radar on Cyprus now and again.

Still, for HF listening in the U.K. it's the onslaught from broadband thru mains, beloved by BT, that is a far bigger problem.


----------



## tunatownshipwreck (Nov 9, 2005)

I remember that thing, I first heard it in September 1976. They had a couple more on line a few years later and would wipe out an entire band. Very infuriating. Sometime in the 1980s they refined it a bit so the sweep was a narrower frequency, but it still interfered with a number of frequencies. I think it was 1989 when Gorbachev shut it down.


----------



## Derek Roger (Feb 19, 2005)

treeve said:


> It was stated to have been simply a part of the early warning system at the time, but it seemed to me to have been a lot more than that, it was said at the time that it would have had to have had massive power. I'll have to have a dig out of my old SWL folders. I have a vague recollection of a form of EMP test being undertaken at the time, but by whom?


Treeve ;

I am in no way an expert in the field however my understanding is that an EMP ( Electro Magnetic Pulse ) can only come from a nuclear explosion / Event . Am I wrong in that ???

Derek


----------



## Derek Roger (Feb 19, 2005)

Also along with EMP was the term DREE . Anybody know what that is ??

Derek


----------



## Derek Roger (Feb 19, 2005)

In case I forget . It is Direct Effect on Electonics . 

I hope I have not blown my relationship with HM Official Secrets Act .


Derek


----------



## BobClay (Dec 14, 2007)

For a while some military equipment fell back on the old thermionic valve, certainly for the front end of the electronics, since they were less likely to be zapped by an EMP. 
It's nice to know that as the blast wave approaches you, and you are about to be vapourized .... at least your radio is still working.
(Cloud)


----------



## King Ratt (Aug 23, 2005)

Its not DREE..its TREE..Transient Radiation Effects on Electronics. First time EMP became apparent was when a USA nuclear airburst took out most of Hawaii's telephone system. It does not affect vaccuum tube (valve) equipment but semiconductors don't like it. A captured Russian MIG was found to have all its radio equipment contained only valves..so they would have survived a nuclear EMP. USA and our stuff was all solid state by then. I believe manufacturers of NATO stuff started putting valve front ends into their products after that.


----------



## tunatownshipwreck (Nov 9, 2005)

King Ratt said:


> Its not DREE..its TREE..Transient Radiation Effects on Electronics. First time EMP became apparent was when a USA nuclear airburst took out most of Hawaii's telephone system. It does not affect vaccuum tube (valve) equipment but semiconductors don't like it. A captured Russian MIG was found to have all its radio equipment contained only valves..so they would have survived a nuclear EMP. USA and our stuff was all solid state by then. I believe manufacturers of NATO stuff started putting valve front ends into their products after that.


I remember that, sometime in the 1970s, a colonel Bablenko flew his MIG from Vladivostok to the US base in Japan or South Korea.


----------

