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Broadcast Transmitter
A broadcast transmitter is an electronic device which radiates radio waves modulated with information content intended to be received by the general public. Examples are a radio broadcasting transmitter which transmits audio (sound) to broadcast radio receivers (radios) owned by the public, or a television transmitter, which transmits moving images (video) to television receivers (televisions). The term often includes the antenna which radiates the radio waves, and the building and facilities associated with the transmitter. A broadcasting station (radio station or television station) consists of a broadcast transmitter along with the production studio which originates the broadcasts. Broadcast transmitters must be licensed by governments, and are restricted to specific frequencies and power levels. Each transmitter is assigned a unique identifier consisting of a string of letters and numbers called a callsign, which must be used in all broadcasts. Exciter In broadcastin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Wave
Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz (GHz) and below. At 300 GHz, the corresponding wavelength is 1 mm (shorter than a grain of rice); at 30 Hz the corresponding wavelength is (longer than the radius of the Earth). Like all electromagnetic waves, radio waves in a vacuum travel at the speed of light, and in the Earth's atmosphere at a close, but slightly lower speed. Radio waves are generated by charged particles undergoing acceleration, such as time-varying electric currents. Naturally occurring radio waves are emitted by lightning and astronomical objects, and are part of the blackbody radiation emitted by all warm objects. Radio waves are generated artificially by an electronic device called a transmitter, which is connected to an antenna which radiates the waves. They are received by another antenna connected to a radio receiver, which p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcast Engineering
Broadcast engineering is the field of electrical engineering, and now to some extent computer engineering and information technology, which deals with radio and television broadcasting. Audio engineering and RF engineering are also essential parts of broadcast engineering, being their own subsets of electrical engineering. Broadcast engineering involves both the Television studio, studio and transmitter aspects (the entire airchain), as well as remote broadcasts. Every Broadcast network, station has a broadcast engineer, though one may now serve an entire station group in a city. In small media markets the engineer may work on a contract basis for one or more stations as needed. Duties Modern duties of a broadcast engineer include maintaining broadcast automation systems for the studio and automatic transmission systems for the transmitter physical plant, plant. There are also important duties regarding Radio masts and towers, radio towers, which must be Preventive maintenanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such as signal amplifier, amplification and current rectifier, rectification. Non-thermionic types such as a vacuum phototube, however, achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light intensities. In both types, the electrons are accelerated from the cathode to the anode by the electric field in the tube. The simplest vacuum tube, the diode (i.e. Fleming valve), invented in 1904 by John Ambrose Fleming, contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through the device—fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anode
An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemonic is ACID, for "anode current into device". The direction of conventional current (the flow of positive charges) in a circuit is opposite to the direction of electron flow, so (negatively charged) electrons flow out the anode of a galvanic cell, into an outside or external circuit connected to the cell. For example, the end of a household battery marked with a "-" (minus) is the anode. In both a galvanic cell and an electrolytic cell, the anode is the electrode at which the oxidation reaction occurs. In a galvanic cell the anode is the wire or plate having excess negative charge as a result of the oxidation reaction. In an electrolytic cell, the anode is the wire or plate upon which excess positive charge is imposed. As a result of this, anion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmitter Roumoules
The Roumoules transmitter is the main broadcasting facility for longwave and mediumwave broadcasting of Radio Monte Carlo near Roumoules, France and is owned by Monaco Media Diffusion. The 1000 and 2000kW transmitters installed are among the most powerful in the world and can be received well at nighttime throughout Europe. Longwave transmitter The longwave transmitter at Roumoules, which was inaugurated in 1974, transmits at 216 kHz (until 1988: 218 kHz) with a transmission power of 1400 kW (until 1976: 2000 kW). It consists of two 1000 kW transmitters switched in parallel, which are however run with 700 kW output power. A third 1000 kW unit has been available since 1983. Although this unit is only used as backup unit, it is possible to switch all three units in parallel, which would allow an operation with a transmission power of 3000 kW. Since 31 March 2020 the transmitter has ceased transmitting the French programme of Radio Monte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warsaw Radio Mast
The Warsaw Radio Mast (Polish: ''Maszt radiowy w Konstantynowie'') was a radio mast located near Gąbin, Poland, and the world's tallest structure at from 1974 until its collapse on 8 August 1991. Designed by Jan Polak, and one of the last radio masts built under Communist rule, the mast was conceived for height and ability to broadcast the "propaganda of the successes" to remote areas such as Antarctica. It was the third tallest structure ever built, being surpassed as the tallest by the Burj Khalifa tower in the United Arab Emirates in 2009 and Merdeka 118 tower in Malaysia in 2022. Designed by Jan Polak, its construction started in July 1970, was completed on 18 May 1974, and its transmitter entered regular service on 22 July of that year. The opening of the mast was met with extensive celebration and news coverage by the Polish Film Chronicle. The tower was used by Warsaw Radio-Television (Centrum Radiowo-Telewizyjne) for longwave radio broadcasting on a frequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longwave Transmitter Allouis
The Allouis longwave transmitter has been France's central longwave broadcast transmitter since 1939. It is located near the village of Allouis. It broadcast the France Inter public radio station from October 1952 until 31 December 2016. Since 2017, it broadcasts only the TDF time signal, which has been renamed ALS162 since 2017. The first transmitter, built in 1939 during the Phoney War, used an aerial with four masts and a transmitter rated at 500 kilowatts.Chronologie des radios françaises en ondes longues 1921–2000 ("Chronology of french long-wave transmitters 1921–2000") It was destroyed in 1944 during the |
Invoice
An invoice, bill or tab is a commerce, commercial document issued by a sales, seller to a buyer relating to a sale transaction and indicating the product (business), products, quantities, and agreed-upon prices for products or Service (economics), services the seller had provided the buyer. Discounts and allowances, Payment terms are usually stated on the invoice. These may specify that the buyer has a maximum number of days to pay and is sometimes offered a discount if paid before the due date. The buyer could have already paid for the products or services listed on the invoice. To avoid confusion and consequent unnecessary communications from buyer to seller, some sellers clearly state in large and capital letters on an invoice whether it has already been paid. From a seller's point of view, an invoice is a ''sales invoice''. From a buyer's point of view, an invoice is a ''purchase invoice''. The document indicates the buyer and seller, but the term ''invoice'' indicates mone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Utility
An electric utility is a company in the electric power industry (often a public utility) that engages in electricity generation and distribution of electricity for sale generally in a regulated market. The electrical utility industry is a major provider of energy in most countries. Electric utilities include investor owned, publicly owned, cooperatives, and nationalized entities. They may be engaged in all or only some aspects of the industry. Electricity markets are also considered electric utilities—these entities buy and sell electricity, acting as brokers, but usually do not own or operate generation, transmission, or distribution facilities. Utilities are regulated by local and national authorities. Electric utilities are facing increasing demandsBy Candace Lombardi, CNET. Utilities: Green tech good for planet, bad for business” February 23, 2010. including aging infrastructure, reliability, and regulation. In 2009, the French company EDF was the world's largest prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnification
Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a calculated number also called "magnification". When this number is less than one, it refers to a reduction in size, sometimes called ''minification'' or ''de-magnification''. Typically, magnification is related to scaling up visuals or images to be able to see more detail, increasing resolution, using microscope, printing techniques, or digital processing. In all cases, the magnification of the image does not change the perspective of the image. Examples of magnification Some optical instruments provide visual aid by magnifying small or distant subjects. * A magnifying glass, which uses a positive (convex) lens to make things look bigger by allowing the user to hold them closer to their eye. * A telescope, which uses its large objective lens or primary mirror to create an image of a distant object and then allows the user to examine the image clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna Gain
In electromagnetics, an antenna's gain is a key performance parameter which combines the antenna's directivity and radiation efficiency. The term ''power gain'' has been deprecated by IEEE. In a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction. In a receiving antenna, the gain describes how well the antenna converts radio waves arriving from a specified direction into electrical power. When no direction is specified, gain is understood to refer to the peak value of the gain, the gain in the direction of the antenna's main lobe. A plot of the gain as a function of direction is called the antenna pattern or radiation pattern. It is not to be confused with directivity, which does ''not'' take an antenna's radiation efficiency into account. Gain or 'absolute gain' is defined as "The ratio of the radiation intensity in a given direction to the radiation intensity that would be produced if the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Radiation
In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic field, electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, Light, (visible) light, ultraviolet, X-rays, and gamma rays. All of these waves form part of the electromagnetic spectrum. Classical electromagnetism, Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric field, electric and magnetic fields. Depending on the frequency of oscillation, different wavelengths of electromagnetic spectrum are produced. In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted ''c''. In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. The position of an electromagnetic wave w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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