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Micropup
In electronics, a micropup is a style of triode vacuum tube (valve) developed by the British General Electric Company (GEC) during World War II for use at very high frequencies such as those used in radar. The first micropup, the VT90, was introduced in 1939 and capable of operating at wavelengths as low as 25 cm, although at low power. The VT90 was much more widely used in a broad variety of radars operating in the 1.5 m band, around 200 MHz, which remained in widespread use for the rest of the war. Improved versions like the NT99 of 1941 allowed operations at 50 cm, or 600 MHz, leading to a series of new radar sets. These saw less use as the introduction of production-quality cavity magnetrons the same year led to microwave-frequency radars that outperformed the best micropups. Description Key to the micropup design is the development of methods to seal glass directly to metal, allowing the construction of mixed-material vacuum chambers. Previously, tubes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics
Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other Electric charge, electrically charged particles. It is a subfield of physics and electrical engineering which uses Passivity (engineering), active devices such as transistors, diodes, and integrated circuits to control and amplify the flow of electric current and to convert it from one form to another, such as from alternating current (AC) to direct current (DC) or from analog signal, analog signals to digital signal, digital signals. Electronic devices have significantly influenced the development of many aspects of modern society, such as telecommunications, entertainment, education, health care, industry, and security. The main driving force behind the advancement of electronics is the semiconductor industry, which continually produces ever-more sophisticated electronic devices and circuits in respo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air-Sea Vessel Radar
Radar, Air to Surface Vessel, or ASV radar for short, is a classification used by the Royal Air Force (RAF) to refer to a series of aircraft-mounted radar systems used to scan the surface of the ocean to locate ships and surfaced submarines. The first examples were developed just before the opening of World War II and they have remained a major instrument on patrol aircraft since that time. It is part of the wider surface-search radar classification, which includes similar radars in ground and ship mountings. The first ASV was developed after the accidental detection of wharves and cranes while testing an AI radar, air-to-air radar in 1937. For a variety of reasons, ASV was easier to develop than the air-to-air variety of the same systems, and the first operational use of the Mark I followed in early 1940. A cleaned-up and repackaged version, ASV Mark II, replaced it at the end of the year, but the system was not widespread until late in 1941. ASV was useful for detecting U-boats a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHORAN
SHORAN is an acronym for SHOrt RAnge Navigation, a type of electronic navigation and bombing system using a precision radar beacon. It was developed during World War II and the first stations were set up in Europe as the war was ending, and was operational with Martin B-26 Marauders based in Corsica, and later based in Dijon and in B-26s given to the South African Airforce in Italy. The first 10/10 zero visibility bombing was over Germany in March 1945. It saw its first combat use in the B-25, B-26 and B-29 bomber aircraft during the Korean War. SHORAN used ground-based transponders to respond to interrogation signals sent from the bomber aircraft. By measuring the round-trip time to and from one of the transponders, the distance to that ground station could be accurately determined. The aircraft flew an arcing path that kept it at a set distance from one of the stations. The distance to a second station was also being measured, and when it reached a set distance from that statio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Battleship Bismarck
''Bismarck'' was the first of two s built for Nazi Germany's . Named after Chancellor Otto von Bismarck, the ship was Keel laying, laid down at the Blohm & Voss shipyard in Hamburg in July 1936 and ceremonial ship launching, launched in February 1939. Work was completed in August 1940, when she was ship commissioning, commissioned into the German fleet. ''Bismarck'' and her sister ship were the largest battleships ever built by Germany, and two of the largest built by any European power. In the course of the warship's eight-month career, ''Bismarck'' conducted only one offensive operation that lasted eight days in May 1941, codenamed . The ship, along with the heavy cruiser , was to break into the Atlantic Ocean and raid Allied shipping from North America to Great Britain. The two ships were detected several times off Scandinavia, and British naval units were deployed to block their route. At the Battle of the Denmark Strait, the battlecruiser initially engaged ''Prinz Eugen'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS Suffolk (55)
HMS ''Suffolk'', pennant number 55, was a heavy cruiser of the Royal Navy, and part of the ''Kent'' subclass. She was built by Portsmouth Dockyard, Portsmouth, UK, with the keel being laid down on 30 September 1924. She was launched on 16 February 1926, and commissioned on 31 May 1928. During World War II, ''Suffolk'' took part in the Norwegian Campaign in 1940 and then the Battle of the Denmark Strait in 1941, before serving in the Arctic throughout the following year. After a refit that concluded in April 1943, the cruiser served in the Far East until the end of the war. In the immediate post-war period, ''Suffolk'' undertook transport duties between the Far East, Australia and the United Kingdom before being placed in reserve in mid-1946. The vessel was sold off and then scrapped in 1948. History Pre-World War II ''Suffolk'', like her sisters, served on the China Station, save for reconstruction, until the outbreak of World War II. In early 1934 she became the flagship of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Navy
The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early Middle Ages, medieval period, the first major maritime engagements were fought in the Hundred Years' War against Kingdom of France, France. The modern Royal Navy traces its origins to the English Navy of the early 16th century; the oldest of the British Armed Forces, UK's armed services, it is consequently known as the Senior Service. From the early 18th century until the World War II, Second World War, it was the world's most powerful navy. The Royal Navy played a key part in establishing and defending the British Empire, and four Imperial fortress colonies and a string of imperial bases and coaling stations secured the Royal Navy's ability to assert naval superior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMES Type 7
The Air Ministry Experimental Station, AMES Type 7, also known as the Final GCI, was a ground-based radar system introduced during World War II by the Royal Air Force (RAF). The Type 7 was the first truly modern radar used by the Allies, providing a 360 degree view of the airspace around the station out to a distance of about . It allowed fighter interceptions to be plotted directly from the radar display, a concept known as ground controlled intercept, or GCI. Earlier radars, like Chain Home (CH), provided the range and angle to a single target at a time. Arranging an intercept required a complex series of reports from multiple radars that were plotted at a central station, the filter room. In a seminal 1939 memo, Robert Hanbury Brown showed that this Dowding system resulted in an inherent inaccuracy of approximately , and the only way to reduce this would be to arrange the interception directly from the radar screen. He suggested spinning the radar antenna and the cathode ray tub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Home Low
Chain Home Low (CHL) was the name of a British early warning radar system operated by the RAF during World War II. The name refers to CHL's ability to detect aircraft flying at altitudes below the capabilities of the original Chain Home (CH) radars, where most CHL radars were co-located. CHL could reliably detect aircraft flying as low as . The official name was AMES Type 2, referring to the Air Ministry Experimental Station at Bawdsey Manor where it was developed, but this name was almost never used in practice. The system had originally been developed by the British Army's research group, also based at Bawdsey, as a system for detecting enemy shipping in the English Channel. It was built using the electronics being developed for the aircraft interception radar systems, which worked on the 1.5 m band. This high frequency (200 MHz), for the era, allowed it to use smaller antennas that could be swung back and forth to look for returns, in contrast to the enormous fixed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airborne Interception Radar
Aircraft interception radar, or AI radar for short, is a historical British term for radar systems used to equip aircraft with the means to find and track other flying aircraft. These radars are used primarily by Royal Air Force (RAF) and Fleet Air Arm night fighters and interceptors for locating and tracking other aircraft, although most AI radars could also be used in a number of secondary roles as well. The term was sometimes used generically for similar radars used in other countries, notably the US. AI radar stands in contrast with ASV radar, whose goal is to detect ships and other sea-surface vessels, rather than aircraft; both AI and ASV are often designed for airborne use. The term was first used circa 1936, when a group at the Bawdsey Manor research center began considering how to fit a radar system into an aircraft. This work led to the AI Mk. IV radar, the first production air-to-air radar system. Mk. IV entered service in July 1940 and reached widespread availabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, thermionic 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. It takes the form of an evacuated tubular envelope of glass or sometimes metal containing electrodes connected to external connection pins. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental Electronics, electronic functions such as signal amplifier, amplification and current Rectifier, rectification. Non-thermionic types such as vacuum phototubes achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light and measurement of its intensity. In both types the electrons are accelerated from the cathode to the anode by the electric field in the tube. The first, and simplest, vacuum tube, the diode or Flem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltages
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a positive test charge from the first point to the second point. In the International System of Units (SI), the derived unit for voltage is the ''volt'' (''V''). The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in a generator). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. Since it is the difference in electric potential, it is a physical scalar quantity. A voltmeter can be used to measure the voltage between two points in a system. Often a common reference potential such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up quark, up and down quark, down quarks. Electrons are extremely lightweight particles that orbit the positively charged atomic nucleus, nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall electric charge#Charge neutrality, neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electron, valence electrons are the least tightly bound and are responsible for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
