The Mühlacker Broadcasting Transmission Facility is a
radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...
transmission facility near
Mühlacker
Mühlacker is a town in the eastern part of the Enz (district), Enz district of Baden-Württemberg, Germany. Mühlacker station has direct rail connections with Stuttgart, Karlsruhe, Heidelberg, Pforzheim and the Northern Black Forest.
Mühlhau ...
, Germany, first put into service on November 21, 1930. It uses two
guyed steel tube masts as aerials and one guyed steel framework mast, which are insulated against ground. It has two transmission
aerials for
shortwave
Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (100 to 10 me ...
and one free standing steel framework tower for directional radio services. The shortwave transmitter was shut off on October 19, 2004. The medium wave transmitter was switched off in January 2012.
Description
At time of inauguration in 1930 the transmitter, which had a power of 60 kW, used a T-type antenna spun between two 100 m high wooden lattice towers placed 310 m apart. As this antenna produced large amounts of
skywave
In radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere. Since it is not limited by the curvature of ...
, the area of undistorted fading-free reception - was in spite of its high transmission power - at night not as large as planned and so it was planned to replace this antenna by an aerial with better skywave suppression. So in 1933–34, a 190 m high wooden tower - the tallest structure ever built of wood - was built, in which a vertical wire antenna, which was electrically enlengthened by a metal ring with 10.6 metres diameters on the top of the tower, was hung up. At this time transmission power was also increased from 60 kW to 100 kW. After inauguration of this antenna, the two original wooden towers were dismantled. One of them was rebuilt at
Koblenz
Koblenz (; Moselle Franconian language, Moselle Franconian: ''Kowelenz''), spelled Coblenz before 1926, is a German city on the banks of the Rhine and the Moselle, a multi-nation tributary.
Koblenz was established as a Roman Empire, Roman mili ...
, the other at
Frankfurt-Heiligenstock. In 1939/1940 a second 100 kW transmitter was installed. It used as antenna a system of 3 T-antennas, which were mounted on 3 50 metres tall guyed masts arranged in a triangle. In opposite to the first transmitter, it was including its aerial designed for a quick change of broadcasting frequency, which was done in case of air attacks in order to form a single frequency network with other transmitters, which hindered hostile aircraft using the signals for navigation purpose. On April 6, 1945, the wooden tower and the masts carrying the system of T-antennas were blown up by the
SS to prevent its capture by the
Allies
An alliance is a relationship among people, groups, or states that have joined together for mutual benefit or to achieve some common purpose, whether or not explicit agreement has been worked out among them. Members of an alliance are called ...
in
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
.
Today, the most important aerial mast in Mühlacker is a 273 m high guyed steel tube mast with a diameter of 1.67 m, located at . This mast, which was built in 1950, is used as a transmitter for the
mediumwave
Medium wave (MW) is the part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. The spectrum provides about 120 channels with more limited sound quality than FM stations on the FM broadcast band. During the dayti ...
frequency 576
kHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
and is therefore insulated against ground. It is designed as an antifading aerial and is therefore double-feedable and insulated. The mast is topped with a butterfly aerial for FM-broadcasting transmitters.
There are flight safety lamps near the ground end of the guy ropes, to make the span of the guy ropes more visible.
Two other radio masts, with heights of 130 m and 80 m, were located at the Mühlacker site.
*The 130 m high mast, situated at , was a steel tube mast, insulated against ground. Before 1996, it was used as a director during nighttime and a spare during daytime. Transmission power was reduced to 100
kW in 1996 and the mast was obsolete and used only as a spare aerial. It was demolished in 2013.
*The 80 m high radio mast, located at , is an insulated guyed steel framework mast with a triangular cross section. It was built in 1977 in order to improve transmission towards the south. It was also used to carry aerials for mobile phone services. It has been demolished.
The three masts are arranged in a nearly straight line on the site. A T-type aerial for shortwave transmission is fixed between two small guyed steel framework masts, but was shut down on October 19, 2004. It was later dismantled.
In 1948, a 110 m tall guyed steel framework mast was built on the site at This served as a transmission aerial for the
American Forces Network
The American Forces Network (AFN) is a government television and radio broadcast service the U.S. military provides to those stationed or assigned overseas. Headquartered at Fort George G. Meade, Maryland, AFN's broadcast operations, which i ...
(AFN) until 1963. From 1963 until its demolition in November 1993, the mast was used as part of a directional aerial for a mediumwave transmitter. It also served as a spare FM transmitter with a butterfly aerial installed on top. The mast was demolished because it was in poor repair and was deemed no longer necessary. Plans for a new mast have not been realized.
Also located here at was a 50 m steel framework mast insulated against ground. It was part of the directional aerial for the AFN transmitter described above. After 1963, it was only used as an aerial for the internal mobile radio service of the transmission facility. It was demolished in April, 2004 and replaced in the summer of 2004 with a 93 m high freestanding steel framework tower carrying aerials for directional services.
See also
*
List of masts
The tallest structure in the world is the Burj Khalifa skyscraper at . Listed are guyed masts (such as telecommunication masts), self-supporting towers (such as the CN Tower), skyscrapers (such as the Willis Tower), oil platforms, electricity t ...
*
List of towers
Several extant building fulfill the engineering definition of a tower: "a tall human structure, always taller than it is wide, for public or regular operational access by humans, but not for living in or office work, and are ''self-supporting' ...
External links
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* http://www.magischesauge.de/muehlacker_chronik.htm
* http://www.skyscraperpage.com/diagrams/?b40728
* http://www.skyscraperpage.com/cities/?buildingID=40731
* http://www.skyscraperpage.com/diagrams/?b28031
* http://www.skyscraperpage.com/diagrams/?b62537
* http://www.skyscraperpage.com/diagrams/?b40733
* http://www.skyscraperpage.com/diagrams/?b47129
Satellite PictureVideo of the demolition of the 130m reflector mast
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1930 establishments in Germany
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Radio masts and towers in Germany