And from the same link Austin provided:
Duga is mobile as suspected !
They consist of tens of antenna-feeder masts with a height of 30 meters. In Kovylkino line of masts stretched nearly a mile. Despite this, Duga quite mobile. Antenna mast systems can quickly enough to meet equipped sites. And all the equipment, including a powerful computing complex, located in transportable containers. Because Duga "Container" does not require special construction of capital facilities, commissioning of new plants can occur quite quickly.
Austin: here is a radar Duga that article mentiones that had 10 000km range and was constructed because of the need to monitor US ballistic missile research.

LINK
It is said that radar could detect Tomahawk lounch from the middle of Atlantic ocean.
Funny part:
In addition, "Doug" violated the radio, because it works on frequencies which are actively used throughout the world. U.S., UK and Canada have expressed even protest the Soviet Union, but without any result. In this assignment so strange radio long remained a mystery. Naturally, the headlines in the Western press quickly filled assumptions that "Russian want to influence the minds of people all over the world." And the news that the signal sent by the ionosphere, quickly led to speculation about the impact of "treacherous Russian" on the Earth's climate. Echoes of these fables and excite the minds of today, including ours.
Interesting part - Russian Navy is using it too !!!!
Second-horizon system is much more sophisticated, the station became "Wave". Their appearance would have been impossible without the participation of the prominent Soviet statesman - Navy Commander Sergei Gorshkov IG. Difficulty with the first Duga led to a skeptical attitude toward him in the Soviet leadership. Sergei G. whereas this was a devotee of military technology breakthrough. His efforts in the Navy were tested first combat laser systems and systems using electromagnetic pulses as damaging factors. Although really effective samples of such weapons only appear today to merit the Soviet Navy Commander should include the fact that he was not afraid to take responsibility, giving the course developments that then seemed fantastic
In 1986, the station "Wave" started working in a test mode in the Far East (near Nakhodka). She was constantly improved, modernized its software and algorithmic complex, increased energy potential. By 1990, the station steadily detect and track aircraft carrying U.S. groups in the Pacific Ocean at distances much higher than 3000 kilometers, and individual air targets - at distances up to 2800 km
Another but different OTH radar systems used by Russian Navy
In 1999, on the Kamchatka Peninsula, in the interest of the fleet, was built new Duga "Taurus". It uses less power and signal used to detect ships and air targets at ranges up to 250 km. Development of the "Taurus" were coastal Duga "Sunflower", which is now being built in different parts of our country and even offered for export. Their range of action is about 450 km.
More than 10 planned.
It was launched in pilot mode in 2002. Since that time have accumulated vast experience horizon radar, and technical facilities of the station repeatedly modernized. Currently, all major modes using it worked, and the Far East started the preparations for the construction of the station has burst "Container". There will be built more than ten such stations, which will in the short term to cover a continuous radar field, throughout the country and extensive adjacent air space.
http://sdelanounas.ru/blogs/44535/
And interesting picture about the size of 29B6 damn thing (click on it)

LINK