Sender Langenberg - AbsoluteAstronomy.com

The Langenberg transmission tower (also translated as "Sender Langenberg" or "Transmission Facility Langenberg") is a broadcasting station that transmits MW

Mediumwave

Medium wave is the part of the medium frequency radio band used mainly for AM radio broadcasting. For Europe the MW band ranges from 526.5 kHz to 1606.5 kHz...

, FM

FM broadcasting

FM broadcasting is a broadcasting technology pioneered by Edwin Howard Armstrong which uses frequency modulation to provide high-fidelity sound over broadcast radio. The term "FM band" describes the "frequency band in which FM is used for broadcasting"...

and TV signals. It is located in Langenberg, Velbert

Velbert

Velbert is a town in the district of Mettmann, in North Rhine-Westphalia, Germany. Langenberg, a district of Velbert, is well known as the location of the Sender Langenberg transmitter site.-Geography:...

, Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

and has had a very turbulent history since its inauguration. The transmitter

Transmitter

In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...

first went into service in 1927 with 60 kilowatts (kW) of power and a T-aerial

T-aerial

A T-aerial is an antenna used for VLF, LF, MF and shortwave transmission or reception.It consists of a horizontal wire suspended between two radio masts or towers. A vertical wire is connected to the middle of the horizontal wire and hangs down close to the ground, where it is connected to the...

hanging on two 100-metre freestanding steel-frame towers insulated against ground.

Attempted manipulatation

In the early 1930s, communist

Communism

Communism is a social, political and economic ideology that aims at the establishment of a classless, moneyless, revolutionary and stateless socialist society structured upon common ownership of the means of production...

underground groups tried to manipulate the line from the studio to the transmitter in order to broadcast their own propaganda. Their attempts failed, but they did manage to attach a red star to the top of one of the towers, which was removed on the same day.

Pre-1945

In 1934 the T-aerial was replaced by an aerial

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

hanging from a 160-metre wood framework tower and the transmission power was increased to 100 kW. However, this tower was destroyed on October 10, 1935 by a tornado

Tornado

A tornado is a violent, dangerous, rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as a twister or a cyclone, although the word cyclone is used in meteorology in a wider...

. After this a triangular aerial hung on three 45-metre freestanding towers was built; this went into service in December 1935. In 1940/41 a second aerial was installed on a 240-metre insulated guyed steel tube mast. The entire aerial system was destroyed by German troops

Axis Powers

The Axis powers , also known as the Axis alliance, Axis nations, Axis countries, or just the Axis, was an alignment of great powers during the mid-20th century that fought World War II against the Allies. It began in 1936 with treaties of friendship between Germany and Italy and between Germany and...

on April 12, 1945.

Post-1945

After World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

forces built two triangular aerials mounted on 6 masts, each 50 metres high. One of these aerials was removed in 1948 and a 160 metre high insulated radio

Radio

Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

mast built on its site. The other aerial was destroyed in a storm in 1949 which broke two of the three masts. The third mast was transformed into an AM

AM broadcasting

AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is carried out in the medium wave band world wide, and on long wave and short wave...

transmitter and was in service until 1957. In 1949 a second radio mast with a height of 120 metres was built, and in 1952 a third guyed mast followed with a height of 210 metres for FM and TV. The 120-metre mast was used as an AM transmitter and was insulated against ground

Ground (electricity)

In electrical engineering, ground or earth may be the reference point in an electrical circuit from which other voltages are measured, or a common return path for electric current, or a direct physical connection to the Earth....

, while the 210-metre mast, used eventually for TV and FM broadcasts, was grounded.

The 1960s

In the middle of the 1960s the transmission power of the AM transmitter was enormously increased and its frequency was changed to the almost clear frequency

Frequency

Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...

of 1586 kHz which allowed night-time reception, even in the USA. This 120-metre radio mast was reduced to 95 metres and it was equipped with two separation insulators.

The 1970s

In course of the workout of the Geneva Frequency Plan of 1975, the facility lost the exclusive frequency of 1586 kHz and the transmitter was retuned to 1593 kHz. Because this frequency is used by other broadcasters, interference

Co-channel interference

Co-channel interference or CCI is crosstalk from two different radio transmitters using the same frequency. There can be several causes of co-channel radio interference; four examples are listed here....

problems occurred at night-time in spite of the 800 kW transmitting power. As compensation, station owner WDR was allotted a second medium wave frequency of 720 kHz for daytime transmission only.

The 1980s

Between 1988 and 1990, the 95-metre mediumwave mast and the 210-metre TV- and FM-mast were replaced by a 301 metre high guyed steel-framework grounded radio mast with a cage aerial

Cage aerial

A Cage aerial is a radio antenna, which consists of the top portion of a tower or mast and of several parallel wires, which are radially arranged around the lower part of the mast. one advantage of the cage aerial is that the supporting tower can be grounded, allowing it to be used for other radio...

for mediumwave in its lower sections.

The 1990s

In 1993, the 1593 kHz mediumwave transmitter was shut down because some components had been manufactured with PCB

Polychlorinated biphenyl

Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...

s. 720 kHz remained in service, but it was not allowed to use this frequency for night transmission until new regulations were enacted in 1995.

At these point there were two radio masts in Langenberg: the 160-metre radio mast for medium wave and the 301-metre radio mast for MW, FM and TV. The shorter mast had to be renovated in 1996; unfortunately, one auxiliary rope tore during this work and the mast collapsed on September 2, 1996.

In 1995 the transmission power had to be reduced for ecological reasons. Until the early 1990s the whole radiated power in the AM range was 1000 kW (800 kW on 1593 kHz and 200 kW on 720 kHz), but after 1995 the transmitter was restricted to 85 kW. After the collapse of the 160 metre mast, radiation power of the AM transmitter was reduced to 20 kW.

Soon after the collapse of the 160 metre mast, WDR planned a new mast in the form of a guyed grounded steel framework with a height of 170 metres and a cage aerial. The medium wave frequency of 1593 kHz was given to Radio Free Europe

Radio Free Europe

Radio Free Europe/Radio Liberty is a broadcaster funded by the U.S. Congress that provides news, information, and analysis to countries in Eastern Europe, Central Asia, and the Middle East "where the free flow of information is either banned by government authorities or not fully developed"...

. The 720 kHz transmitter was fitted with a directional antenna that minimized propagation of signals westward. Construction of the new mast started in the middle of 1999, but problems delayed its inauguration until July 2000. After the inauguration of the new 170-metre radio mast, transmitter power on medium wave could be once again increased to 85 kW.

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