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Sterba Antenna
Before the HRS antenna became the default design for high power broadcasting in the 1950s, Sterba curtains were used to transmit shortwave broadcasts. Sterba curtains are modest-gain single-band curtain array antennas. They are named after Ernest J. Sterba, who developed a simple shortwave curtain array for Bell Labs in the 1930s. Sterba curtain arrays are described in William Orr's Radio Handbook. There are multiple feed arrangements for the Sterba curtain arrays, as with HRS type antennas. However, Sterba arrays provide a limited gain-bandwidth system for the demands of modern shortwave broadcasting systems therefore they are significantly less common than more modern options, such as an ALLISS ALLISS is a somewhat rotatable antenna system for high power shortwave radio broadcasting in the 6 MHz to 26 MHz range. An ALLISS module is a self-contained shortwave relay station that is used for international broadcasting. Backgrou ... system. Sterba curtain arrays p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HRS Antenna
Curtain arrays are a class of large multielement directional radio transmitting wire antennas, used in the shortwave radio bands. They are a type of reflective array antenna, consisting of multiple wire dipole antennas, suspended in a vertical plane, often in front of a "curtain" reflector made of a flat vertical screen of many long parallel wires. These are suspended by support wires strung between pairs of tall steel towers, up to high. They are used for long-distance skywave (or ''skip'') transmission; they transmit a beam of radio waves at a shallow angle into the sky just above the horizon, which is reflected by the ionosphere back to Earth beyond the horizon. Curtain antennas are mostly used by international short wave radio stations to broadcast to large areas at transcontinental distances. Because of their powerful directional characteristics, curtain arrays are often used in government propaganda radio stations to beam propaganda broadcasts over national borde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curtain Array
Curtain arrays are a class of large multielement directional radio transmitting wire antennas, used in the shortwave radio bands. They are a type of reflective array antenna, consisting of multiple wire dipole antennas, suspended in a vertical plane, often in front of a "curtain" reflector made of a flat vertical screen of many long parallel wires. These are suspended by support wires strung between pairs of tall steel towers, up to high. They are used for long-distance skywave (or ''skip'') transmission; they transmit a beam of radio waves at a shallow angle into the sky just above the horizon, which is reflected by the ionosphere back to Earth beyond the horizon. Curtain antennas are mostly used by international short wave radio stations to broadcast to large areas at transcontinental distances. Because of their powerful directional characteristics, curtain arrays are often used in government propaganda radio stations to beam propaganda broadcasts over national borde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William I
William I; ang, WillelmI (Bates ''William the Conqueror'' p. 33– 9 September 1087), usually known as William the Conqueror and sometimes William the Bastard, was the first Norman king of England, reigning from 1066 until his death in 1087. A descendant of Rollo, he was Duke of Normandy from 1035 onward. By 1060, following a long struggle to establish his throne, his hold on Normandy was secure. In 1066, following the death of Edward the Confessor, William invaded England, leading an army of Normans to victory over the Anglo-Saxon forces of Harold Godwinson at the Battle of Hastings, and suppressed subsequent English revolts in what has become known as the Norman Conquest. The rest of his life was marked by struggles to consolidate his hold over England and his continental lands, and by difficulties with his eldest son, Robert Curthose. William was the son of the unmarried Duke Robert I of Normandy and his mistress Herleva. His illegitimate status and his youth caused some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALLISS
ALLISS is a somewhat rotatable antenna system for high power shortwave radio broadcasting in the 6 MHz to 26 MHz range. An ALLISS module is a self-contained shortwave relay station that is used for international broadcasting. Background ALLISS is a special design case of HRS type antennas. True ALLISS systems have solid radiators (horizontal radiating elements) versus tensioned flexible (open) radiators found with all other variations of ITU HRS type antennas systems. The name is based on a concatenation of two French towns ALLouis and ISSoudun. Technological ambiguities There are some factors that separate true ALLISS technology from 'run-of-the-mill' rotatable HRS Type antennas. Thales pseudo-ALLISS rotatable antenna designs were procured from other antenna manufacturers that Thales acquired by corporate transactions. Technically only solid radiators distinguish true ALLISS systems from all other rotatable HRS type antennas. Only about 12% (estimate) of all HRS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency Antenna Types
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 transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, 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 objects like aircraft, ships, spacecraft an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
