January 10th, 2010

In May 2009, Romkatel delivered 3 radiating systems (UHF, VHF and FM) for the new TV tower located in Avala, near Belgrad. Due to these new radiating systems, the Serbian Radio Television will be able to broadcast FM radio programs and also DVB-T television programs.

The tower was inaugurated in 1965, destroyed in 1999 and rebuilt in 2006

In 1965, it was the only tower in the world to have an equilateral triangle as its cross section and one of very few towers not perched directly into the ground, but standing on its legs. The legs formed a tripod, making it one of the few towers to be constructed in this manner. The Avala tower was destroyed in NATO bombardment of Serbia on 29 April 1999. Between the date of its destruction and 11 September 2001, it was the tallest building ever destroyed. On 21 December 2006, the reconstruction of Avala Tower commenced and was finished on 22 October 2009, preserving the original aspect of the tower. Besides providing Belgrad with radio and television signal, the tower also represents an opportunity for recreation, due to the restaurant located on the top platform, where the visitors can enjoy an extraordinary panoramic scenery.

An UHF radiating system will be installed on the upper part of the tower

It consists of 12 levels, each having 4 Kathrein panels, supplied by Romkatel. The support structure system is composed of 3 metal sections, each with a mass of approx. 1 ton and a total length of 18 meters. Besides being a supplier, Romkatel’s specialized teams also installed the equipment of the UHF system (connectors, rigid lines, patch panel, combiner, antenna, splitter, jumpers) and the 10 feeders. The broadcast room is located below the tower and the patch panel system (which enables one to switch the 3 Kathrein radiating systems between half-or whole antenna operating) is located in the cabin on the 180 meter top platform. The connection between the broadcast room and the top platform is provided by 4 feeders, one for each radiating system and a spare one. From the top platform to each half of the antenna there are other 6 feeders installed.

In September 2009, Romkatel team has completed the installation of the 4 feeders

Two have a 5" diameter, one 4 1 / 8" and another one 3 1 / 8 ". Because of the narrow space, the route available for the feeder installation required the presence of some curves, depending on the mechanical bending limit of the feeder. Each feeder was installed at a time, so that each drum was positioned at the beginning of the climbing ramp of the tower. Then the feeders were guided by a roller system along their horizontal length and on the vertical side were drawn using a hand winch. Because of the tortuous route and the feeder size (e.g. a 5" feeder weighs about 1.7 tones, its outer diameter is 15 cm and its minimum radius of curvature 1.6 m), only small steps can be made to advance, due to the use of a hand winch and not an automatic one, in order to avoid possible mechanical destructive tensions that may arise from the feeder. This installation required the allocation of special resources and it lasted a few days. All the 10 feeders were installed safely in their final position of functioning.