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Short-wave Receiver
A shortwave radio receiver is a radio receiver that can receive one or more shortwave bands, between 1.6 and 30 MHz. A shortwave radio receiver often receives other broadcast bands, such as FM radio, Longwave and Mediumwave. Shortwave radio receivers are often used by dedicated hobbyists called shortwave listeners. History While home built shortwave receivers had been used by amateur radio operators and radio experimenters prior to World War I, the first time shortwave radio reception was available to the general public was through the use of shortwave frequency converters sold as accessories to broadcast-band radio sets during the mid 1920s. Such converters were generally found unsatisfactory in performance, and so dedicated shortwave receiving sets soon appeared on the market. National Radio Company introduced the SW-2 "Thrill box" shortwave regenerative receiver in 1927, and later offered improved models, such as the highly regarded SW-3. Other notable early shortwave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Receiver E5
In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique while others talk of a "plurality of worlds". Some treat the world as #Monism and pluralism, one simple object while others analyze the world as a complex made up of many parts. In ''#Scientific cosmology, scientific cosmology'' the world or universe is commonly defined as "[t]he totality of all space and time; all that is, has been, and will be". ''#Theories of modality, Theories of modality'', on the other hand, talk of possible worlds as complete and consistent ways how things could have been. ''#Phenomenology, Phenomenology'', starting from the horizon of co-given objects present in the periphery of every experience, defines the world as the biggest horizon or the "horizon of all horizons". In ''#Philosophy of mind, philosop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regenerative Circuit
A regenerative circuit is an amplifier circuit that employs positive feedback (also known as regeneration or reaction). Some of the output of the amplifying device is applied back to its input so as to add to the input signal, increasing the amplification. One example is the Schmitt trigger (which is also known as a regenerative comparator), but the most common use of the term is in RF amplifiers, and especially regenerative receivers, to greatly increase the gain of a single amplifier stage. The regenerative receiver was invented in 1912 and patented in 1914US Patent 1113149A, Edwin H. Armstrong, Wireless receiving system', filed October 29, 1913, granted October 6, 1914 by American electrical engineer Edwin Armstrong when he was an undergraduate at Columbia University. It was widely used between 1915 and World War II. Advantages of regenerative receivers include increased sensitivity with modest hardware requirements, and increased selectivity because the Q of the tuned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid State Electronics
Solid-state electronics means semiconductor electronics: electronic equipment using semiconductor devices such as transistors, diodes and integrated circuits (ICs). The term is also used as an adjective for devices in which semiconductor electronics that have no moving parts replace devices with moving parts, such as the solid-state relay in which transistor switches are used in place of a moving-arm electromechanical relay, or the solid-state drive (SSD) a type of semiconductor memory used in computers to replace hard disk drives, which store data on a rotating disk. History The term "solid-state" became popular at the beginning of the semiconductor era in the 1960s to distinguish this new technology based on the transistor, in which the electronic action of devices occurred in a solid state, from previous electronic equipment that used vacuum tubes, in which the electronic action occurred in a gaseous state. A semiconductor device works by controlling an electric current ... [...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] |
Myrna Loy
Myrna Loy (born Myrna Adele Williams; August 2, 1905 – December 14, 1993) was an American film, television and stage actress. Trained as a dancer, Loy devoted herself fully to an acting career following a few minor roles in silent films. She was originally typecast in exotic roles, often as a vamp or a woman of Asian descent, but her career prospects improved greatly following her portrayal of Nora Charles in ''The Thin Man'' (1934). Born in Helena, Montana, Loy was raised in rural Radersburg during her early childhood, before relocating to Los Angeles with her mother in her early adolescence. There, she began studying dance, and trained extensively throughout her high school education. She was discovered by production designer Natacha Rambova, who helped facilitate film auditions for her, and she began obtaining small roles in the late 1920s, mainly portraying vamps. Her role in ''The Thin Man'' helped elevate her reputation as a versatile actress, and she reprised the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trans-Oceanic
The Trans-Oceanic (abbreviated T/O) was a brand of portable radios produced from 1941 to 1981 by Zenith Radio. They were characterized by heavy-duty, high-quality construction and their performance as shortwave receivers. History Zenith's founder, Lieutenant Commander Eugene F. McDonald, was a great admirer of advancing technology and believed that his company should include the latest, most practical advances in a sturdy product that would to enhance the company's reputation. Of the many products of Zenith Radio, the 'Trans-Oceanic' series of portable radios were among the most famous. McDonald was a keen yachtsman and outdoorsman and wished for a portable radio that would provide entertainment broadcasts as well as being able to tune into weather, marine and international shortwave stations. He asked his company's engineers to develop prototypes to meet his criteria and by 1940 they had concept sets that were ready for production. The Trans-Oceanic remains popular among colle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromberg-Carlson
Stromberg-Carlson was a telecommunications equipment and electronics manufacturing company in the United States. It was formed in 1894 as a partnership by Swedish immigrants Alfred Stromberg (1861 Varnhem, Sweden - 1913 Chicago) and Androv Carlson (1854 Tommared, Sweden - 1925 Chicago). It was one of five companies that controlled the national supply of telephone equipment until after World War II.Cohen, ''The Racketeer's Progress: Chicago and the Struggle for the Modern American Economy, 1900-1940,'' 2004. History In 1894, Alexander Graham Bell's expired. Stromberg and Carlson,Chicago employees of the American Bell Telephone Company (later AT&T), each invested $500 to establish a firm to manufacture equipment, primarily subscriber sets, for sale to independent telephone companies. Stromberg-Carlson was originally located in Chicago, with Carlson managing manufacturing and Stromberg responsible for marketing. Stromberg-Carlson quickly established a reputation for relia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emerson Radio
Emerson Radio Corporation is one of the United States' largest volume consumer electronics distributors and has a recognized trademark in continuous use since 1912. The company designs, markets, and licenses many product lines worldwide, including products sold, and sometimes licensed, under the brand name G Clef, an homage to Emerson's logo. History 1915–1920 Emerson Radio Corp. was incorporated in 1915 as Emerson Phonograph Co. (NAICS: 421620 Consumer Electronics Wholesaling), based in New York City, by an early recording engineer and executive, Victor Hugo Emerson, who was at one time employed by Columbia Records. The first factories were opened in Chicago and Boston in 1920. In December of that year, the company fell victim to the sales slump which affected the entire phonograph industry caused by the post-World War I recession and the growth of the rapidly expanding commercial radio industry in the early 1920s. The company quickly went from the self-claimed third la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philco
Philco (an acronym for Philadelphia Battery Company) is an American electronics industry, electronics manufacturer headquartered in Philadelphia. Philco was a pioneer in battery, radio, and television production. In 1961, the company was purchased by Ford Motor Company, Ford and, from 1966, renamed "Philco-Ford". Ford sold the company to GTE in 1974, and it was purchased by Philips in 1981. In North America, the Philco brand is currently owned by Philips. In other markets, the Philco International brand is owned by Electrolux. In the early 1920s, Philco made storage batteries, "socket power" battery eliminator units (plug-in transformers), and battery chargers. With the invention of the rectifier tube, which made it practical to power radios by electrical outlets, in 1928, Philco entered the radio business. They followed other radio makers such as RCA, Atwater-Kent, Zenith Electronics, Freshman Masterpiece, FADA Radio (Frank A. D'Andrea Radio), and AH Grebe into the battery-powere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenith Electronics Corporation
Zenith Electronics, LLC, is an American research and development company that develops ATSC and digital rights management technologies. It is owned by the South Korean company LG Electronics. Zenith was previously an American brand of consumer electronics, a manufacturer of radio and television receivers and other consumer electronics, and was headquartered in Glenview, Illinois. After a series of layoffs, the consolidated headquarters moved to Lincolnshire, Illinois. For many years, their famous slogan was "The quality goes in before the name goes on". LG Electronics acquired a controlling share of Zenith in 1995; Zenith became a wholly owned subsidiary in 1999. Zenith was the inventor of subscription television and the modern remote control, and was the first to develop high-definition television (HDTV) in North America. Zenith-branded products were sold in North America, Germany, Thailand (to 1983), Cambodia, Laos, Vietnam, India, and Myanmar. History The company was co-fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammarlund Super Pro
The Hammarlund Super Pro was an American-made radio communications receiver. History In March 1936, the Hammarlund Manufacturing Company initiated the first of the famous "Super-Pro" line, the SP-10 receiver, followed in January 1937 by the SP-100. Their efforts to improve the design resulted in October 1939 with the SP-200 series, an 18-tube, single conversion superhet receiver. The SP-200 series Super-Pro receivers were manufactured through 1945, with thousands delivered to the military during World War II; they saw wide use by the U.S. Signal Corps as the BC-779. During World War II, government agencies like the FBI used the 200 Series Super-Pro at their listening posts. Many were used at ground stations in England to communicate with the Royal Air Force and U.S. Air Force armadas that flew bombing missions over Germany. According to a November 1940 QST Magazine ad, "The fact that 'Super-Pro' receivers are used extensively by the U.S. Signal Corps and many other governmental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hallicrafters SX-28
The Hallicrafters SX-28 "Super Skyrider" is an American shortwave communications receiver that was produced between 1940 and 1946 that saw wide use by amateur radio, government and military services. History In July 1940, the Hallicrafters Company announced the SX-28 "Super Skyrider", the result of a development effort by 12 staff engineers and analysis of more than 600 reports that included input from U.S. government engineers, commercial users, and amateur radio operators. The SX-28's distinctive art deco styling was considered sleek and strikingly modern in 1940. The radio frequency coverage was 550 kHz (0.55 MHz) to 43 MHz in six bands. The SX-28 included an Amplified AVC, a Lamb Noise Silencer, Calibrated bandspread, and Push-Pull audio output. The SX-28 was known for its high fidelity audio together with high sensitivity, stability and selectivity, and good purchase value.http://www.radioblvd.com/SX28Notes.html Western Historic Radio Museum, ''The Hallicrafters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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