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SCR-720
The SCR-720 was a World War II Airborne Interception radar designed by the Radiation Laboratory (RadLab) at MIT in the United States. It was used by US Army Air Force night fighters as well as the Royal Air Force (RAF) in a slightly modified version known as Radar, Airborne Interception, Mark X, or AI Mk. X for short. SCR-720 was the first radar to successfully use the "helical-scan" technique, which became common in night fighter radars. The concept was first raised in early 1940 as part of UK research using the cavity magnetron as the basis of a microwave-frequency radar system. They abandoned this approach as they were unable to solve the problem of feeding microwave power to a spinning antenna. The concept was revealed to US researchers as part of the Tizard Mission during the summer of 1940, and the RadLab decided to press on with the concept. This led to the SCR-520 of 1942, designed for installation on large aircraft like the P-70 Havoc and P-61 Black Widow. Only 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northrop P-61 Black Widow
The Northrop P-61 Black Widow is a twin-engine United States Army Air Forces fighter aircraft of World War II. It was the first operational U.S. warplane designed as a night fighter, and the first aircraft designed specifically as a night fighter. Named for the North American spider ''Latrodectus mactans'', it was an all-metal, twin-engine, twin-boom design armed with four forward-firing 20 mm (.79 in) Hispano M2 autocannon in the lower fuselage, and four M2 Browning machine guns in a dorsal gun turret. Developed during the war, the first test flight was made on May 26, 1942, with the first production aircraft rolling off the assembly line in October 1943. Although not produced in the large numbers of its contemporaries, the Black Widow was operated effectively as a night fighter by United States Army Air Forces squadrons in the European Theater, Pacific Theater, China Burma India Theater, and Mediterranean Theater during World War II. It replaced earlier British ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Laboratory (MIT)
The Radiation Laboratory, commonly called the Rad Lab, was a microwave and radar research laboratory located at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. It was first created in October 1940 and operated until 31 December 1945 when its functions were dispersed to industry, other departments within MIT, and in 1951, the newly formed MIT Lincoln Laboratory. The use of microwaves for various radio and radar uses was highly desired before the war, but existing microwave devices like the klystron were far too low powered to be useful. Alfred Lee Loomis, a millionaire and physicist who headed his own private laboratory, organized the Microwave Committee to consider these devices and look for improvements. In early 1940, Winston Churchill organized what became the Tizard Mission to introduce U.S. researchers to several new technologies the UK had been developing. Among these was the cavity magnetron, a leap forward in the creation of microwaves that made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douglas A-20 Havoc
The Douglas A-20 Havoc (company designation DB-7) is an American medium bomber, attack aircraft, Intruder (air combat), night intruder, night fighter, and reconnaissance aircraft of World War II. Designed to meet an Army Air Corps requirement for a bomber, it was ordered by France for their air force before the USAAC decided it would also meet their requirements. French DB-7s were the first to see combat; after the fall of France, the bomber served with the Royal Air Force under the British military aircraft designation systems#Names, service name Boston. From 1941, night fighter and Intruder (air combat), intruder versions were given the service name Havoc. In 1942 USAAF A-20s saw combat in North Africa. It served with several Allies of World War II, Allied air forces, principally the United States Army Air Forces (USAAF), the Soviet Air Forces (''VVS''), Soviet Naval Aviation (''AVMF''), and the Royal Air Force (RAF) of the United Kingdom. A total of 7,478 aircraft were built, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gain (electronics)
In electronics, gain is a measure of the ability of a two-port electrical network, circuit (often an amplifier) to increase the Electric power, power or amplitude of a Signal (electrical engineering), signal from the input to the output port by adding energy converted from some power supply to the signal. It is usually defined as the mean ratio of the Signalling (telecommunication), signal amplitude or power at the output port (circuit theory), port to the amplitude or power at the input port. It is often expressed using the logarithmic decibel (dB) units ("dB gain"). A gain greater than one (greater than zero dB), that is amplification, is the defining property of an active component or circuit, while a passive circuit will have a gain of less than one. The term ''gain'' alone is ambiguous, and can refer to the ratio of output to input voltage (''voltage gain''), Electric current, current (''current gain'') or electric power (''power gain''). In the field of audio and general ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against France. The modern Royal Navy traces its origins to the early 16th century; the oldest of the UK's armed services, it is consequently known as the Senior Service. From the middle decades of the 17th century, and through the 18th century, the Royal Navy vied with the Dutch Navy and later with the French Navy for maritime supremacy. From the mid 18th century, it was the world's most powerful navy until the Second World War. 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 superiority globally. Owing to this historical prominence, it is common, even among non-Britons, to ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conning Tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and ground tackle. It is usually located as high on the ship as practical, to give the conning team good visibility of the entirety of the ship, ocean conditions, and other vessels. The naval term "conn" may derive from the Middle English ''conne'' (study, become acquainted with) or French ''conduire'' from Latin ''conducere'' (conduct). Surface ships On surface ships, the conning tower was a feature of all battleships and armored cruisers from about 1860 to the early years of World War II. Located at the front end of the superstructure, the conning tower was a heavily armored cylinder, with tiny slit windows on three sides providing a reasonable field of view. Designed to shield just enough personnel and devices for navigation during battle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-Boat
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role (commerce raiding) and enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, and from the United States, to the United Kingdom and (during the Second World War) to the Soviet Union and the Allied territories in the Mediterranean. German submarines also destroyed Brazilian merchant ships during World War II, causing Brazil to declare war on both Germany and Italy on 22 August 1942. The term is an anglicised version of the German word ''U-Boot'' , a shortening of ''Unterseeboot'' ('under-sea-boat'), though the German term refers to any submarine. Austro-Hungarian Navy submarines were also kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klystron
A klystron is a specialized linear-beam vacuum tube, invented in 1937 by American electrical engineers Russell and Sigurd Varian,Pond, Norman H. "The Tube Guys". Russ Cochran, 2008 p.31-40 which is used as an amplifier for high radio frequencies, from UHF up into the microwave range. Low-power klystrons are used as oscillators in terrestrial microwave relay communications links, while high-power klystrons are used as output tubes in UHF television transmitters, satellite communication, radar transmitters, and to generate the drive power for modern particle accelerators. In a klystron, an electron beam interacts with radio waves as it passes through resonant cavities, metal boxes along the length of a tube. The electron beam first passes through a cavity to which the input signal is applied. The energy of the electron beam amplifies the signal, and the amplified signal is taken from a cavity at the other end of the tube. The output signal can be coupled back into the input cavi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Birmingham
, mottoeng = Through efforts to heights , established = 1825 – Birmingham School of Medicine and Surgery1836 – Birmingham Royal School of Medicine and Surgery1843 – Queen's College1875 – Mason Science College1898 – Mason University College1900 – gained university status by royal charter , city = Birmingham , province = West Midlands , country = England, UK , coor = , campus = Urban, suburban , academic_staff = 5,495 (2020) , administrative_staff = , head_label = Visitor , head = The Rt Hon Penny Mordaunt MP , chancellor = Lord Bilimoria , vice_chancellor = Adam Tickell , type = Public , endowment = £134.5 million (2021) , budget = £774.1 million (2020–21) , students = () , undergrad = () , postgrad = () , affiliations = Universitas 21Universities UK EUA ACUSutton 13Russell Group , free_label = , free = , colours = The University , website = , logo = The University of Birmingham (informally Birmingham University) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Havilland Sea Vixen
The de Havilland DH.110 Sea Vixen is a British twin-engine, twin boom-tailed, two-seat, carrier-based fleet air-defence fighter flown by the Royal Navy's Fleet Air Arm during the 1950s through to the early 1970s. The Sea Vixen was designed by the de Havilland Aircraft Company during the late 1940s at its Hatfield aircraft factory in Hertfordshire, developed from the company's earlier first generation jet fighters. It was later called the Hawker Siddeley Sea Vixen after de Havilland was absorbed by the Hawker Siddeley Corporation in 1960. The Sea Vixen had the distinction of being the first British two-seat combat aircraft to achieve supersonic speed, albeit not in level flight. Operating from British aircraft carriers, it was used in combat over Tanganyika and over Yemen during the Aden Emergency. In 1972, the Sea Vixen was phased out in favour of the American-made McDonnell Douglas Phantom FG.1 interceptor. There have been no flying Sea Vixens since 2017. Development Orig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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