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M9 Gun Director
The M9 Gun Director was an electronic director developed by Bell Labs during World War II. This computer continuously calculated trigonometric firing solutions for anti-aircraft weapons against enemy aircraft. When cued by the SCR-584 centimetric gun-laying radar and used in concert with anti-aircraft guns firing shells with proximity fuzes, it helped form the most effective anti-aircraft weapon system utilized by the Allies during the war. Background During the late 1930s the United States Army's Signal Corps attempted to utilize the newly developed SCR-268 radar to provide fire control quality data to the Sperry Corporation's M4 mechanical gun director. The SCR-268's longwave did not provide accurate enough data for the pairing to be an effective anti-aircraft weapon. In 1940, Vannevar Bush formed the National Defense Research Committee and its section D-2 was tasked with examining issues related to fire control headed by Warren Weaver. Development In May 1940, an engineer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Telephone Magazine (1922) (14569949459)
A bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an internal "clapper" or "uvula", an external hammer, or—in small bells—by a small loose sphere enclosed within the body of the bell (jingle bell). Bells are usually cast from bell metal (a type of bronze) for its resonant properties, but can also be made from other hard materials. This depends on the function. Some small bells such as ornamental bells or cowbells can be made from cast or pressed metal, glass or ceramic, but large bells such as a church, clock and tower bells are normally cast from bell metal. Bells intended to be heard over a wide area can range from a single bell hung in a turret or bell-gable, to a musical ensemble such as an English ring of bells, a carillon or a Russian zvon which are tuned to a common scale and installe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longwave
In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the early 20th century, when the radio spectrum was considered to consist of longwave (LW), medium-wave (MW), and short-wave (SW) radio bands. Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short'. In contemporary usage, the term ''longwave'' is not defined precisely, and its intended meaning varies. It may be used for radio wavelengths longer than 1,000 m i.e. frequencies up to 300 kilohertz (kHz), including the International Telecommunication Union's (ITU's) low frequency (LF, 30–300 kHz) and very low frequency (VLF, 3–30 kHz) bands. Sometimes the upper limit is taken to be higher than 300 kHz, but not above the start of the medium wave broadcast band at 520&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M3 Gun Data Computer
The gun data computer was a series of artillery computers used by the U.S. Army for coastal artillery, field artillery and anti-aircraft artillery applications. In antiaircraft applications they were used in conjunction with a director. Variations * M1: This was used by seacoast artillery for major-caliber seacoast guns. It computed continuous firing data for a battery of two guns that were separated by not more than . It utilised the same type of input data furnished by a range section with the then-current (1940) types of position-finding and fire-control equipment. * M3: This was used in conjunction with the M9 and M10 directors to compute all required firing data, i.e. azimuth, elevation and fuze time. The computations were made continuously, so that the gun was at all times correctly pointed and the fuze correctly timed for firing at any instant. The computer was mounted in the M13 or M14 director trailer. * M4: This was identical to the M3 except for some mechanisms and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cicero, Illinois
Cicero (originally known as Hawthorne) is a suburb of Chicago and an Incorporated town#Illinois, incorporated town in Cook County, Illinois, Cook County, Illinois, United States. Per the 2020 United States Census, 2020 census, the population was 85,268. making it the List of cities in Illinois#Most populous places, 11th largest municipality in Illinois. The town of Cicero is named after Cicero, Marcus Tullius Cicero, a Roman Republic, Roman statesman and orator. History Originally, Cicero Township, Cook County, Illinois, Cicero Township occupied an area six times the size of its current territory. The cities of Oak Park, Illinois, Oak Park and Berwyn, Illinois, Berwyn were incorporated from portions of Cicero Township, and other portions, such as Austin, Chicago, Austin, were annexed into the city of Chicago. By 1911, an aerodrome called the ''Cicero Flying Field'' had been established as the town's first aircraft facility of any type, located on a roughly square plot of land abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawthorne Works
The Hawthorne Works was a large factory complex of the Western Electric Company in Cicero, Illinois. Named after the original name of the town, Hawthorne, it opened in 1905 and operated until 1983. At its peak of operations, Hawthorne employed 45,000 workers, producing large quantities of telephone equipment, but also a wide variety of consumer products. The facility is well-known for the industrial studies held there in the 1920s and the Hawthorne effect is named for the works. History The Hawthorne Works complex was built at the intersection of Cicero Avenue and Cermak Road and was opened in 1905. Hawthorne Works was named for Hawthorne, Illinois, a small town that was later incorporated as Cicero. The facility consisted of several buildings and contained a private railroad, Manufacturers' Junction Railway, to move shipments through the plant to the nearby Chicago, Burlington and Quincy Railroad freight depot. In the first decades, the factory complex was significantly expa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware River and Pennsylvania; and on the southwest by Delaware Bay and the state of Delaware. At , New Jersey is the fifth-smallest state in land area; but with close to 9.3 million residents, it ranks 11th in population and first in population density. The state capital is Trenton, and the most populous city is Newark. With the exception of Warren County, all of the state's 21 counties lie within the combined statistical areas of New York City or Philadelphia. New Jersey was first inhabited by Native Americans for at least 2,800 years, with the Lenape being the dominant group when Europeans arrived in the early 17th century. Dutch and Swedish colonists founded the first European settlements in the state. The British later seized control o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mullica Hill
Mullica Hill is a census-designated place (CDP) and unincorporated community in Harrison Township in Gloucester County, New Jersey. As of the 2010 United States census, the CDP's population was 3,982.DP-1 - Profile of General Population and Housing Characteristics: 2010 Demographic Profile Data for Mullica Hill CDP, New Jersey . Accessed November 10, 2012. History [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attack On Pearl Harbor
The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service upon the United States against the naval base at Pearl Harbor in Honolulu, Territory of Hawaii, just before 8:00a.m. (local time) on Sunday, December 7, 1941. The United States was a neutral country at the time; the attack led to its formal entry into World War II the next day. The Japanese military leadership referred to the attack as the Hawaii Operation and Operation AI, and as Operation Z during its planning. Japan intended the attack as a preventive action. Its aim was to prevent the United States Pacific Fleet from interfering with its planned military actions in Southeast Asia against overseas territories of the United Kingdom, the Netherlands, and those of the United States. Over the course of seven hours there were coordinated Japanese attacks on the US-held Philippines, Guam, and Wake Island and on the British Empire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mervin Kelly
Mervin Joseph Kelly (February 14, 1894 – March 18, 1971) was an American industrial physicist. He worked at Bell Labs from 1925 to 1959, in which time he held positions such as director of research, president, and chairman of the board of directors. Early life and education Mervin Joseph Kelly was born in Princeton, Missouri on February 14, 1894.Kelly, Mervin Joseph American National Biography His parents were Mary Etta (née Evans) and Joseph Fenimore Kelly. Mervin's great-great-grandfather had moved from Ireland to Virginia, while his mother's parents were Welsh. At the time of Kelly's birth, his father was a high school principal. The family soon moved to |
Harvey Fletcher
Harvey Fletcher (September 11, 1884 – July 23, 1981) was an American physicist. Known as the "father of stereophonic sound", he is credited with the invention of the 2-A audiometer and an early electronic hearing aid. He was an investigator into the nature of speech and hearing, and made contributions in acoustics, electrical engineering, speech, medicine, music, atomic physics, sound pictures, and education. Following his death, he was credited with collaborating with his doctoral advisor, Robert Millikan, on the Nobel-prize winning oil drop experiment which first determined the charge of the electron. Early years Fletcher was born in Provo, Utah. He graduated from Brigham Young High School in 1904. He enrolled at Brigham Young University (BYU), graduating in 1907 with a bachelor's degree. He married Lorena Chipman. They were the parents of seven children. Harvey Fletcher was the father of James C. Fletcher, former president of the University of Utah and NASA Administrator a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potentiometer
A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat. The measuring instrument called a potentiometer is essentially a voltage divider used for measuring electric potential (voltage); the component is an implementation of the same principle, hence its name. Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as position transducers, for example, in a joystick. Potentiometers are rarely used to directly control significant power (more than a watt), since the power dissipated in the potentiometer would be comparable to the power in the controlled load. Nomenclature There are a number of terms in the electronics industry used to describe certain types of potentiometers: * slide pot or slider pot: a potentiomete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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