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List Of Vacuum Tubes
This is a list of vacuum tubes or ''thermionic valves'', and low-pressure gas-filled tubes, or ''discharge tubes''. Before the advent of semiconductor devices, thousands of tube types were used in consumer electronics. Many industrial, military or otherwise professional tubes were also produced. Only a few types are still used today, mainly in high-power, high-frequency applications. Heater or filament ratings Receiving tubes have heaters or filaments intended for direct battery operation, parallel operation off a dedicated winding on a supply transformer, or series string operation on transformer-less sets. High-power RF power tubes are directly heated; the heater voltage must be much smaller than the signal voltage on the grid and is therefore in the 5...25 V range, drawing up to hundreds of amperes from a suitable heater transformer. In some valve part number series, the voltage class of the heater is given in the part number, and a similar valve might be available with s ...
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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 ...
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Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is still in Eindhoven. Philips was formerly one of the largest electronics companies in the world, but is currently focused on the area of health technology, having divested its other divisions. The company was founded in 1891 by Gerard Philips and his father Frederik, with their first products being light bulbs. It currently employs around 80,000 people across 100 countries. The company gained its royal honorary title (hence the ''Koninklijke'') in 1998 and dropped the "Electronics" in its name in 2013, due to its refocusing from consumer electronics to healthcare technology. Philips is organized into three main divisions: Personal Health (formerly Philips Consumer Electronics and Philips Domestic Appliances and Personal Care), Connecte ...
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Power Amplifier Classes
In electronics, power amplifier classes are letter symbols applied to different power amplifier types. The class gives a broad indication of an amplifier's characteristics and performance. The classes are related to the time period that the active amplifier device is passing current, expressed as a fraction of the period of a signal waveform applied to the input. A class A amplifier is conducting through all the period of the signal; Class B only for one-half the input period, class C for much less than half the input period. A Class D amplifier operates its output device in a switching manner; the fraction of the time that the device is conducting is adjusted so a pulse-width modulation output is obtained from the stage. Additional letter classes are defined for special-purpose amplifiers, with additional active elements or particular power supply improvements; sometimes a new letter symbol is used by a manufacturer to promote its proprietary design. Power amplifier classes Powe ...
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Eimac
Eimac is a trade mark of Eimac Products, part of the Microwave Power Products Division of Communications & Power Industries. It produces power vacuum tubes for radio frequency applications such as broadcast and radar transmitters. The company name is an initialism from the names of the founders, William Eitel and Jack McCullough. History The San Francisco Bay area was one of the early centers of amateur radio activity and experimentation, containing about 10% of the total operators in the US. Amateur radio enthusiasts sought vacuum tubes that would perform at higher power and on higher frequencies than those then available from RCA, Western Electric, General Electric, and Westinghouse. Additionally, they required tubes that would operate with the limited voltages available from typical amateur power supplies. While employed by the small San Francisco, California manufacturing firm of Heintz & Kaufman which manufactured custom radio equipment, Bill Eitel (amateur radio call sign W6UF ...
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List Of EIA Professional Tubes
A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby union club Other uses * Angle of list, the leaning to either port or starboard of a ship * List (information), an ordered collection of pieces of information ** List (abstract data type), a method to organize data in computer science * List on Sylt, previously called List, the northernmost village in Germany, on the island of Sylt * ''List'', an alternative term for ''roll'' in flight dynamics * To ''list'' a building, etc., in the UK it means to designate it a listed building that may not be altered without permission * Lists (jousting), the barriers used to designate the tournament area where medieval knights jousted * ''The Book of Lists'', an American series of books with unusual lists See also * The List (other) * Listing (di ...
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Westinghouse Electric (1886)
The Westinghouse Electric Corporation was an American manufacturing company founded in 1886 by George Westinghouse. It was originally named "Westinghouse Electric & Manufacturing Company" and was renamed "Westinghouse Electric Corporation" in 1945. The company acquired the CBS television network in 1995 and was renamed "CBS Corporation" until being acquired by Viacom in 1999, a merger completed in April 2000. The CBS Corporation name was later reused for one of the two companies resulting from the split of Viacom in 2006. The Westinghouse trademarks are owned by Westinghouse Electric Corporation, and were previously part of Westinghouse Licensing Corporation. The nuclear power business, Westinghouse Electric Company, was spun off from the Westinghouse Electric Corporation in 1999. History Westinghouse Electric was founded by George Westinghouse in Pittsburgh, Pennsylvania, on January 8, 1886. The firm became active in developing electric infrastructure throughout the U ...
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Sovtek
Sovtek is a brand of vacuum tube owned by Mike Matthews's New Sensor Corporation and manufactured in Saratov, Russia. They are often used in guitar Guitar amplifier, amplification and include versions of the popular 12AX7, EL84, EL34, and 6L6 vacuum tubes. Many of the vacuum-tube amplifiers in modern production are factory-fitted with Sovtek valves. Originally, Sovtek guitar amplifier valves were claimed to have been descendants of earlier wartime Russian-made components and carried blast proof capabilities. This, however, was later dispelled as urban myth, attributed to a sales person who promoted early product at music industry trade shows worldwide. In the 1990s, Sovtek also manufactured tube amplifiers at factories in Saint Petersburg, Saratov, and Novosibirsk. Several models were offered for guitar and bass. Sovtek brand speaker cabinets fitted with US-made Eminence speakers were also offered. At the same time, Sovtek manufactured variants of several effects pedals already man ...
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Svetlana (company)
PJSC Svetlana (russian: ПАО «Светлана») is a company based in Saint Petersburg, Russia. It is primarily involved in the research, design, and manufacturing of electronic and microelectronic instruments. Svetlana is part of Ruselectronics. The name of the company is said to originate from the words for 'light of an incandescent lamp' (СВЕТ ЛАмпы НАкаливания). History The company was established in 1889 as the Ya. M. Aivaz (russian: Я. М. Айваз) Factory. Svetlana was a major producer of vacuum tubes. In 1937, the Soviet Union purchased a tube assembly line from RCA The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ..., including production licenses and initial staff training, and installed it on the St Petersburg plant. US-licensed tubes were pr ...
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Machlett Laboratories
Machlett Laboratories was a Northeastern United States-based company that manufactured X-ray and high-power vacuum tubes. Machlett was a large producer of the tubes and developed accessories to be used with them as well. For its contributions to World War II efforts, the US government gave it an "E" award in 1945. The company was bought by Varian in 1989. History The company began as E. Machlett and Son, which was founded in 1897 in New York City, United States as scientific glass makers. Early days Machlett Laboratories was created from E. Machlett & Sons in order to exploit the then new technology of X-rays. They made X-ray tubes from the beginning to 1989 when they were bought by Varian. In addition to making X-ray tubes, they manufactured high-power vacuum tubes for use in radio and TV broadcasting (857B mercury-vapor half-wave rectifier tube) and for industrial induction heating. Those two sides of the business were about equivalent for most of the life of the company. Ma ...
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General Electric Company
The General Electric Company (GEC) was a major British industrial conglomerate involved in consumer and defence electronics, communications, and engineering. The company was founded in 1886, was Britain's largest private employer with over 250,000 employees in the 1980s, and at its peak in the 1990s, made profits of over £1 billion a year. In June 1998, GEC sold its share of the joint venture GEC-Alsthom on the Paris stock exchange. In December 1999, GEC's defence arm, Marconi Electronic Systems, was sold to British Aerospace, forming BAE Systems. The rest of GEC, mainly telecommunications equipment manufacturing, continued as Marconi Communications. After buying several US telecoms manufacturers at the top of the market, losses following the bursting of the dot-com bubble in 2001 led to the restructuring in 2003 of Marconi plc into Marconi Corporation plc. In 2005, Ericsson acquired the bulk of that company. What was left of the business was renamed Telent. History ...
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General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energy, digital industry, additive manufacturing and venture capital and finance, but has since divested from several areas, now primarily consisting of the first four segments. In 2020, GE ranked among the Fortune 500 as the 33rd largest firm in the United States by gross revenue. In 2011, GE ranked among the Fortune 20 as the 14th most profitable company, but later very severely underperformed the market (by about 75%) as its profitability collapsed. Two employees of GE – Irving Langmuir (1932) and Ivar Giaever (1973) – have been awarded the Nobel Prize. On November 9, 2021, the company announced it would divide itself into three investment-grade public companies. On July 18, 2022, GE unveiled the brand names of the companies it will ...
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