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ITT-Gilfillan
Gilfillan Brothers, later known as ITT-Gilfillan, was an American electronics company located in Los Angeles, best known for their radar systems. They changed names several times, and might be referred to as ITT Corporation Electronic Systems Radar Systems - Gilfillan or ITT Industries, Gilfillan Division, depending on the source. They were spun off by ITT in 2011 to form a division of the newly created Exelis Inc. Exelis was in turn purchased in 2015 by Harris Corporation and then merged in 2019 to become part of L3Harris Technologies. History The company traces its history to 1912, when Sennet Gilfillan took over his uncle's smelting company, which processed precious metals such as platinum and iridium. He was joined by his brother Jay to form Gilfillan Brothers in 1914. During World War I they produced platinum points for automobile ignition systems and branched out to aircraft parts. In the 1920s they began making radio receivers and were best known for their Bakelite radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles
Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, cultural center of Southern California. With an estimated 3,878,704 residents within the city limits , it is the List of United States cities by population, second-most populous in the United States, behind only New York City. Los Angeles has an Ethnic groups in Los Angeles, ethnically and culturally diverse population, and is the principal city of a Metropolitan statistical areas, metropolitan area of 12.9 million people (2024). Greater Los Angeles, a combined statistical area that includes the Los Angeles and Riverside–San Bernardino metropolitan areas, is a sprawling metropolis of over 18.5 million residents. The majority of the city proper lies in Los Angeles Basin, a basin in Southern California adjacent to the Pacific Ocean in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrodyne
The Neutrodyne radio receiver, invented in 1922 by Louis Hazeltine, was a particular type of tuned radio frequency (TRF) receiver, in which the instability-causing inter-electrode capacitance of the triode RF tubes is cancelled out or "neutralized"US Patent No. 1450080, Louis Alan Hazeltine "Method and electric circuit arrangement for neutralizing capacity coupling" filed August 7, 1919; granted March 27, 1923 to prevent parasitic oscillations which caused "squealing" or "howling" noises in the speakers of early radio sets. In most designs, a small extra winding on each of the RF amplifiers' tuned anode coils was used to generate a small antiphase signal, which could be adjusted by special variable trim capacitors to cancel out the stray signal coupled to the grid via plate-to-grid capacitance. The Neutrodyne circuit was popular in radio receivers until the 1930s, when it was superseded by the superheterodyne receiver. History The circuit was developed about 1922 by Haro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airport Surveillance Radar
An airport surveillance radar (ASR) is a radar system used at airports to detect and display the presence and position of aircraft in the ''terminal area'', the airspace around airports. It is the main air traffic control system for the airspace around airports. At large airports it typically controls traffic within a radius of 60 miles (96 km) of the airport below an elevation of 25,000 feet. The sophisticated systems at large airports consist of two different radar systems, the ''primary'' and ''secondary'' surveillance radar. The primary radar typically consists of a large rotating parabolic antenna dish that sweeps a vertical fan-shaped beam of microwaves around the airspace surrounding the airport. It detects the position and range of aircraft by microwaves reflected back to the antenna from the aircraft's surface. The secondary surveillance radar consists of a second rotating antenna, often mounted on the primary antenna, which interrogates the transponders of air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Air Force
The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Following the Allies of World War I, Allied victory over the Central Powers in 1918, the RAF emerged as the largest air force in the world at the time. Since its formation, the RAF has played History of the Royal Air Force, a significant role in Military history of the United Kingdom, British military history. In particular, during the Second World War, the RAF established Air supremacy, air superiority over Nazi Germany's Luftwaffe during the Battle of Britain, and led the Allied strategic bombing effort. The RAF's mission is to support the objectives of the British Ministry of Defence (United Kingdom), Ministry of Defence (MOD), which are to "provide the capabilities nee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIT Radiation Laboratory
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precision Approach Radar
Precision approach radar or PAR is a type of radar guidance system designed to provide lateral and vertical guidance to an aircraft pilot for landing, until the landing threshold is reached. Controllers monitoring the PAR displays observe each aircraft's position and issue instructions to the pilot that keep the aircraft on course and glidepath during final approach. After the aircraft reaches the decision height (DH) or decision altitude (DA), further guidance is advisory only. The overall concept is known as ground-controlled approach (GCA), and this name was also used to refer to the radar systems in the early days of its development. PAR radars use a unique type of radar display with two separate "traces", separated vertically. The upper trace shows the elevation of a selected aircraft compared to a line displaying the ideal glideslope, while the lower shows the aircraft's horizontal position relative to the runway midline. GCA approaches normally start with the controller ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superheterodyne
A superheterodyne receiver, often shortened to superhet, is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency. It was invented by French radio engineer and radio manufacturer Lucien Lévy. Virtually all modern radio receivers use the superheterodyne principle. Precursors Early radio Early Morse code radio broadcasts were produced using an alternator connected to a spark gap. The output signal was at a carrier frequency defined by the physical construction of the gap, modulated by the alternating current signal from the alternator. Since the output frequency of the alternator was generally in the audible range, this produces an audible amplitude modulated (AM) signal. Simple radio detectors filtered out the high-frequency carrier, leaving the modulation, which was passed on to the user's headphones as an audible signal of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bakelite
Bakelite ( ), formally , is a thermosetting polymer, thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde. The first plastic made from synthetic components, it was developed by Belgian chemist Leo Baekeland in Yonkers, New York, in 1907, and patented on December 7, 1909. Bakelite was one of the first plastic-like materials to be introduced into the modern world and was popular because it could be Molding (process), molded and then hardened into any shape. Because of its electrical nonconductor, nonconductivity and heat-resistant properties, it became a great commercial success. It was used in electrical insulators, radio and telephone casings, and such diverse products as kitchenware, jewelry, pipe stems, children's toys, and firearms. The retro appeal of old Bakelite products has made them collectible. The creation of a synthetic plastic was revolutionary for the chemical industry, which at the time made most of its income f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, map weather formations, and terrain. The term ''RADAR'' was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging". The term ''radar'' has since entered English and other languages as an anacronym, a common noun, losing all capitalization. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwave domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
