|
EF50
In the field of electronics, the EF50 is an early all-glass wideband remote cutoff pentode designed in 1938 by Philips. It was a landmark in the development of vacuum tube technology, departing from construction ideas of the time essentially unchanged from light bulb designs. Initially used in television receivers, it quickly gained a vital role in British radar and great efforts were made to secure a continuing supply of the device as Holland fell in World War II. The EF50 tube is a 9-pin Loctal-socket device with short internal wires to nine short chromium-iron pins, making it suitable for Very High Frequency (VHF) use. History The EF50 was preceded by RCA's acorn design and several other attempts, such as the "Stahlröhre" (~steel tube) from Telefunken, to reduce inductance in the wire leads, all with some disadvantages. Philips had been working since 1934–1935 on an alternative that would solve the problems of the other bases, and a design that could be produced cheaply a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EF50
In the field of electronics, the EF50 is an early all-glass wideband remote cutoff pentode designed in 1938 by Philips. It was a landmark in the development of vacuum tube technology, departing from construction ideas of the time essentially unchanged from light bulb designs. Initially used in television receivers, it quickly gained a vital role in British radar and great efforts were made to secure a continuing supply of the device as Holland fell in World War II. The EF50 tube is a 9-pin Loctal-socket device with short internal wires to nine short chromium-iron pins, making it suitable for Very High Frequency (VHF) use. History The EF50 was preceded by RCA's acorn design and several other attempts, such as the "Stahlröhre" (~steel tube) from Telefunken, to reduce inductance in the wire leads, all with some disadvantages. Philips had been working since 1934–1935 on an alternative that would solve the problems of the other bases, and a design that could be produced cheaply a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tube Socket
Tube sockets are electrical sockets into which vacuum tubes (electronic valves) can be plugged, holding them in place and providing terminals, which can be soldered into the circuit, for each of the pins. Sockets are designed to allow tubes to be inserted in only one orientation. They were used in most tube electronic equipment to allow easy removal and replacement. When tube equipment was common, retailers such as drug stores had vacuum tube testers, and sold replacement tubes. Some Nixie tubes were also designed to use sockets. Throughout the tube era, as technology developed, sometimes differently in different parts of the world, many tube bases and sockets came into use. Sockets are not universal; different tubes may fit mechanically into the same socket, though they may not work properly and possibly become damaged. Tube sockets were typically mounted in holes on a sheet metal chassis and wires or other components were hand soldered to lugs on the underside of the socket. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentode
A pentode is an electronic device having five electrodes. The term most commonly applies to a three-grid amplifying vacuum tube or thermionic valve that was invented by Gilles Holst and Bernhard D.H. Tellegen in 1926. The pentode (called a ''triple-grid amplifier'' in some literature) was developed from the ''screen-grid tube'' or ''shield-grid tube'' (a type of tetrode tube) by the addition of a grid between the screen grid and the plate. The screen-grid tube was limited in performance as an amplifier due to secondary emission of electrons from the plate. The additional grid is called the ''suppressor grid''. The suppressor grid is usually operated at or near the potential of the cathode and prevents secondary emission electrons from the plate from reaching the screen grid. The addition of the suppressor grid permits much greater output signal amplitude to be obtained from the plate of the pentode in amplifier operation than from the plate of the screen-grid tube at the same plate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn Tube
The 955 is typical of the acorn designs, named for the glass cap holding the terminals with the main part of the tube extending from it. An acorn tube, or acorn valve, refers to any member of a family of VHF/UHF vacuum tubes starting just before World War II. They were named after their resemblance to the acorn, specifically due to the glass cap at one end of the tube that looked similar to the cap on an acorn. The acorn tubes found widespread use in radios and radar systems. High-frequency performance is limited by (1) parasitic lead inductance and capacitance and skin effect, and (2) electron transit time (the time required to travel from cathode to anode). Transit time effects are complicated, but one simple effect is the phase margin; another one is input conductance, also known as grid loading. At extremely high frequencies, electrons arriving at the grid may become out of phase with those departing towards the anode. This imbalance of charge causes the grid to exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bawdsey Manor
Bawdsey Manor stands at a prominent position at the mouth of the River Deben close to the village of Bawdsey in Suffolk, England, about northeast of London. Built in 1886, it was enlarged in 1895 as the principal residence of Sir William Cuthbert Quilter. Requisitioned by the Devonshire Regiment during World War I and having been returned to the Quilter family after the war, it was purchased by the Air Ministry for £24,000 in 1936 to establish a new research station for developing the Chain Home RDF (radar) system. RAF Bawdsey was a base through the Cold War until the 1990s. The manor is now used by PGL for courses and children's holidays. There is a small museum in the radar transmitter block. History Quilter period: 1886 to 1936 Bawdsey Manor was built in 1886 and enlarged in 1895 by William Quilter who was an art collector, one of the founders of the National Telephone Company, and was Liberal/Liberal Unionist Member of Parliament for Sudbury. He established a st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sylvania Electric Products
Sylvania Electric Products Inc. was an American manufacturer of diverse electrical equipment, including at various times radio transceivers, vacuum tubes, semiconductors, and mainframe computers such as MOBIDIC. They were one of the companies involved in the development of the COBOL programming language. History The ''Hygrade Sylvania Corporation'' was formed when '' NILCO'', ''Sylvania'' and '' Hygrade Lamp Company'' merged into one company in 1931. In 1939, Hygrade Sylvania started preliminary research on fluorescent technology, and later that year, demonstrated the first linear, or tubular, fluorescent lamp. It was featured at the 1939 New York World's Fair. Sylvania was also a manufacturer of both vacuum tubes and transistors. In 1942, the company changed its name to Sylvania Electric Products Inc. During World War II, Sylvania was chosen from among several competing companies to manufacture the miniature vacuum tubes used in proximity fuze shells due to its quality st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rogers Vacuum Tube Company
Rogers Vacuum Tube Company (formally named Radio Manufacturing Corporation Limited) was founded as the Standard Radio Manufacturing Corporation in 1925 by Edward Rogers (1900–1939) to sell Rogers "Batteryless" radios using vacuum tube technology. It was later renamed Rogers Majestic Corporation Limited when Rogers merged his company with Majestic Corporation of Chicago in 1928. The new company controlled Rogers Radio Tube Company and Rogers Batteryless Radio Company. Joseph Elsworth Rogers (1898–1960), brother of Edward Rogers, was an important member of the company and served as vice-president until 1939, and then as head from 1939 to 1960. The company founded Toronto AM radio station CFRB in order to promote its invention of a batteryless radio receiver, as well as demonstrate the invention of a radio transmitter using batteryless alternating current tubes, making CFRB the first all-mains-electric radio station in the world. Edward Rogers died in 1939, and the company was sold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marconi-Osram Valve
M-OV (Marconi-Osram Valve Company) was a British manufacturer of thermionic valves (vacuum tubes). It was a subsidiary of the (British) General Electric Company Ltd. The company was founded in 1919, when the valve making interests of GEC (Osram) and the Marconi Company were combined. In 1929, Marconi sold its interest in the company to the Gramophone Company, a predecessor of EMI. In 1939, M-OV acquired two disused cotton mills at Shaw, Oldham where it established a shadow factory to produce valves and cathode ray tubes. The two mills named Cape and Duke, were bought from the Lancashire Cotton Corporation for £7,000. Cape mill was used as the main production facility at Shaw, with the adjacent Duke mill remaining mostly unused. Shaw produced a vast array of valves for the war effort, some of which are listed below. * VT104 and VT105 for the T1154 transmitter. * VR99, VR100, VR101 and VR103 for the R1155 receiver. * TT11 for the TR1143 fighter set. * VT90 micropup used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Die (manufacturing)
A die is a specialized machine tool used in manufacturing industries to cut and/or form material to a desired shape or profile. Stamping dies are used with a press, as opposed to drawing dies (used in the manufacture of wire) and casting dies (used in molding) which are not. Like molds, dies are generally customized to the item they are used to create. Products made with dies range from simple paper clips to complex pieces used in advanced technology. Continuous-feed laser cutting may displace the analogous die-based process in the automotive industry, among others. Die stamping Blanking and piercing are two die cutting operations, and bending is an example of a die forming operation. Die forming Forming operations work by deforming materials like sheet metal or plastic using force ( compression, tension, or both) and rely on the material's mechanical properties. Forming dies are typically made by tool and die makers and put into production after mounting into a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS Windsor (D42)
The third HMS ''Windsor'' (D42) was a W-class destroyer of the British Royal Navy that saw service in the final months of World War I and in World War II. Construction and commissioning ''Windsor'' was ordered on 9 December 1916, and was laid down by Scotts Shipbuilding and Engineering Company at Greenock, Scotland, in April 1917. Launched on 21 June 1918, she was completed on 28 August 1918 and commissioned the same day. She was assigned the pennant number F12 in September 1918; it was changed to D42 during the interwar period. Service history World War I Upon completion, ''Windsor'' was assigned to the Grand Fleet, based at Scapa Flow in the Orkney Islands, in which she served for the rest of World War I. She was present at the surrender of the Imperial German Navy's High Seas Fleet in November 1918. Interwar ''Windsor'' was assigned to the 6th Destroyer Flotilla in the Atlantic Fleet in 1921. In 1928, she was part of the Portsmouth Local Flotilla. World War II 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Destroyer
In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in 1885 by Fernando Villaamil for the Spanish NavySmith, Charles Edgar: ''A short history of naval and marine engineering.'' Babcock & Wilcox, ltd. at the University Press, 1937, page 263 as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War. Before World War II, destroyers were light vessels with little endurance for unat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Frequency
In communications and electronic engineering, an intermediate frequency (IF) is a frequency to which a carrier wave is shifted as an intermediate step in transmission or reception. The intermediate frequency is created by mixing the carrier signal with a local oscillator signal in a process called heterodyning, resulting in a signal at the difference or beat frequency. Intermediate frequencies are used in superheterodyne radio receivers, in which an incoming signal is shifted to an IF for amplification before final detection is done. Conversion to an intermediate frequency is useful for several reasons. When several stages of filters are used, they can all be set to a fixed frequency, which makes them easier to build and to tune. Lower frequency transistors generally have higher gains so fewer stages are required. It's easier to make sharply selective filters at lower fixed frequencies. There may be several such stages of intermediate frequency in a superheterodyne receiver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Sylvania Electric Products")
