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Langenberg Transmission Tower
The Langenberg transmission tower (also translated as "Sender Langenberg" or "Transmission Facility Langenberg") is a broadcasting station for analog FM Radio and Digital- TV (DVB-T2 HD) signals. It is located in Langenberg, Velbert, Germany and owned and operated by Westdeutscher Rundfunk, WDR. The history of the transmitting site is very changing. The transmitter first went into service in 1927 with 60 kilowatts (kW) of power and a T-aerial hanging on two 100-metre freestanding steel-frame towers insulated against ground. History In 1926 the „Westdeutschen Funkstunde“ and an association of locals agreed to build the transmitter tower in Langenberg. On Januar 15. 1927 the transmitter was inaugurated. In the early 1930s, communist 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Catastrophic Collapses Of Broadcast Masts And Towers
This is a list of catastrophic collapses of broadcast masts and towers. Masts and towers can collapse as a result of natural disasters, such as storms and fires; from engineering defects; and from accidents, sabotage or warfare. __TOC__ List of collapses References {{Disasters Antennas (radio) * History of structural engineering * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Towers
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 transmission towers, and bridge support towers. This list is organized by absolute height. See History of the world's tallest structures, Tallest structures by category, and List of tallest buildings for additional information about these types of structures. Terminology Terminological and listing criteria follow Council on Tall Buildings and Urban Habitat definitions. Guyed masts are differentiated from towers – the latter not featuring any guy wires or other support structures; and buildings are differentiated from towers – the former having at least 50% of occupiable floor space although both are self-supporting structures. Lists by height This list includes structures of all types over 350 meters (1148 feet). Plus it includes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Free Europe
Radio Free Europe/Radio Liberty (RFE/RL) is a media organization broadcasting news and analyses in 27 languages to 23 countries across Eastern Europe, Central Asia, the Caucasus, and the Middle East. Headquartered in Prague since 1995, RFE/RL operates 21 local bureaus with over 500 core staff, 1,300 freelancers, and 680 employees. Nicola Careem serves as the editor-in-chief. Founded during the Cold War, RFE began in 1949 targeting Soviet empire, Soviet satellite states, while RL, established in 1951, focused on the Soviet Union. Initially funded covertly by the Central Intelligence Agency, CIA until 1972, the two merged in 1976. RFE/RL was headquartered in Munich from 1949 to 1995, with additional broadcasts from Portugal's Glória do Ribatejo until 1996. Soviet authorities jammed their signals, and Second World, communist regimes often infiltrated their operations. Today, RFE/RL is a private 501(c)(3) corporation supervised by the United States Agency for Global Media, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychlorinated Biphenyl
Polychlorinated biphenyls (PCBs) are organochlorine compounds with the formula Carbon, C12Hydrogen, H10−''x''Chloride, Cl''x''; they were once widely used in the manufacture of carbonless copy paper, as heat transfer fluids, and as dielectric and coolant fluids for electrical equipment. They are highly toxic and carcinogenic chemical compounds, formerly used in industrial and consumer electronic products, whose production was banned internationally by the Stockholm Convention on Persistent Organic Pollutants in 2001. Because of their longevity, PCBs are still widely in use, even though their manufacture has declined drastically since the 1960s, when a multitude of problems was identified. With the discovery of PCBs' environmental toxicity, and classification as persistent organic pollutants, their production was banned for most uses by United States federal law on January 1, 1978. The International Agency for Research on Cancer (IARC) rendered PCBs as definite carcinogens i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cage Aerial
A cage antenna (British cage aerial) is a radio antenna where a conventional design has been augmented by replacing a single long conductor with several parallel wires, connected at their ends, and held in position by ring spacers or support struts mounted on a central mast (if any). The "cage" is either mounted around a central mast (either conducting or non-conducting) or suspended from overhead wires. Examples A few examples of areal made of cage sections are: ; Quadrant antenna : A quadrant antenna is an omnidirectional shortwave transmitting antenna shaped like a rhombus or lozenge, made from two identical, opposing L-shaped cage dipoles lying in the same horizontal plane, aligned with their 'elbows' pointing in opposite directions ; Curtain antenna : A curtain array antenna is a directional shortwave transmitting antenna made of several parallel-aligned dipoles, each made of cage sections. History In 1921, an amateur radio operator An amateur radio operator is som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Co-channel Interference
Co-channel interference or CCI is crosstalk from two different radio transmitters using the same channel. Co-channel interference can be caused by many factors from weather conditions to administrative and design issues. Co-channel interference may be controlled by various radio resource management schemes. Cellular mobile networks In cellular mobile communication (GSM & LTE Systems, for instance), frequency spectrum is a precious resource which is divided into non-overlapping spectrum bands which are assigned to different cells (In cellular communications, a cell refers to the hexagonal/circular area around the base station antenna). However, after certain geographical distance, these frequency bands are re-used, i.e. the same spectrum bands are reassigned to other distant cells. The co-channel interference arises in the cellular mobile networks owing to this phenomenon of frequency reuse. Thus, besides the intended signal from within the cell, signals at the same freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geneva Frequency Plan Of 1975
The Final Acts of the Regional Administrative LF/MF Broadcasting Conference (Regions 1 and 3) Geneva, 1975 is the internationally agreed frequency plan which was drawn up to implement the provisions of the Final Acts of the Regional Administrative LF/MF Broadcasting Conference (Regions 1 and 3) held in Geneva, Switzerland, in 1975. It covers radio broadcasting in the long- and medium-wave bands outside the Americas (a separate agreement being in place for North and South America). The plan was drawn up under the auspices of the World Administrative Radio Conference (WARC) of the International Telecommunication Union (ITU) with the assistance of the European Broadcasting Union (EBU/UER). The Geneva plan replaced the 1948 Copenhagen plan. It became necessary because of the large number of broadcasting stations in these frequency ranges leading to ever more mutual interference (many countries had refused to ratify the Copenhagen plan and compliance was patchy even among those w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilohertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base units is 1/s or s−1, meaning that one hertz is one per second or the reciprocal of one second. It is used only in the case of periodic events. It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. For high frequencies, the unit is commonly expressed in multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
