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H. Leslie (Les) Hoffman
H. Leslie Hoffman (1906 – June 24, 1971) was an American businessman. He was the founder and CEO of Hoffman Radio from 1941 to 1971, which changed its name to Hoffman Radio and Television in 1948. In the 1950s, he formed Hoffman Electronics Corporation, based in El Monte, California, consisting of several electronic divisions involved with consumer, industrial and military products. He was married to Elaine Stevely Hoffman (1906–1989). Together in 1954, they formed the H. Leslie Hoffman and Elaine S. Hoffman Foundation, Pasadena, California, Pasadena, a Philanthropy, philanthropic organization. He and his wife Elaine were large donors and supporters of the University of Southern California (USC) and were directly involved with its growth, academic growth and stature. Hoffman served on the Board of Trustees at USC for 17 years. Period before Hoffman Radio Between 1929 and 1931, a company called Mission Bell Radio Manufacturing Company was formed. They were based in Los An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, 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 objects like aircraft, ships, spacecraf ... [...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] |
Solar Cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.Solar Cells chemistryexplained.com It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as , , or resistance, vary when exposed to light. Individual solar cell devices are often the electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electrical power, power. The transistor is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more are found embedded in integrated circuits. Austro-Hungarian physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transistor in 1926, but it was not possible to actually constru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-submarine Warfare
Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades. Successful ASW operations typically involved a combination of sensor and weapon technologies, along with effective deployment strategies and sufficiently trained personnel. Typically, sophisticated sonar equipment is used for first detecting, then classifying, locating, and tracking a target submarine. Sensors are therefore a key element of ASW. Common weapons for attacking submarines include torpedoes and naval mines, which can both be launched from an array of air, surface, and underwater platforms. ASW capabilities are often considered of significant strategic importance, particularly following provocative instan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerial Navigation
The basic principles of air navigation are identical to general navigation, which includes the process of planning, recording, and controlling the movement of a craft from one place to another. Successful air navigation involves piloting an aircraft from place to place without getting lost, not breaking the laws applying to aircraft, or endangering the safety of those on board or on the ground. Air navigation differs from the navigation of surface craft in several ways; Aircraft travel at relatively high speeds, leaving less time to calculate their position en route. Aircraft normally cannot stop in mid-air to ascertain their position at leisure. Aircraft are safety-limited by the amount of fuel they can carry; a surface vehicle can usually get lost, run out of fuel, then simply await rescue. There is no in-flight rescue for most aircraft. Additionally, collisions with obstructions are usually fatal. Therefore, constant awareness of position is critical for aircraft pilots. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Countermeasures
A countermeasure is a measure or action taken to counter or offset another one. As a general concept, it implies precision and is any technological or tactical solution or system designed to prevent an undesirable outcome in the process. The first known use of the term was in 1923. "Countermeasure" defined Countermeasures can refer to the following disciplinary spectrum: * Medicine * Materials engineering * Electro-magnetic engineering * Policing * Information technology * * Diplomatic security * Pollution prevention * Aviation Defense countermeasures are often divided into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Communications
Military communications or military signals involve all aspects of communications, or conveyance of information, by armed forces. Military communications span from pre-history to the present. The earliest military communications were delivered by runners. Later, communications progressed to visual and audible signals, and then advanced into the electronic age. Examples from ''Jane's Military Communications'' include text, audio, facsimile, tactical ground-based communications, naval signalling, terrestrial microwave, tropospheric scatter, satellite communications systems and equipment, surveillance and signal analysis, security, direction finding and jamming.IHS Jane'sMilitary Communications Retrieved 2012-01-23. History In past centuries communicating a message usually required someone to go to the destination, bringing the message. Thus, the term ''communication'' often implied the ability to transport people and supplies. A place under siege was one that lost communicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves 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 information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor
A semiconductor is a material which has an electrical resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glass. Its electrical resistivity and conductivity, resistivity falls as its temperature rises; metals behave in the opposite way. Its conducting properties may be altered in useful ways by introducing impurities ("doping (semiconductor), doping") into the crystal structure. When two differently doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers, which include electrons, ions, and electron holes, at these junctions is the basis of diodes, transistors, and most modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second-most common s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consumer
A consumer is a person or a group who intends to order, or uses purchased goods, products, or services primarily for personal, social, family, household and similar needs, who is not directly related to entrepreneurial or business activities. The term most commonly refers to a person who purchases goods and services for personal use. Consumer rights “Consumers, by definition, include us all," said President John F. Kennedy, offering his definition to the United States Congress on March 15, 1962. This speech became the basis for the creation of World Consumer Rights Day, now celebrated on March 15. In his speech : John Fitzgerald Kennedy outlined the integral responsibility to consumers from their respective governments to help exercise consumers' rights, including: *The right to safety: To be protected against the marketing of goods that are hazardous to health or life. *The right to be informed: To be protected against fraudulent, deceitful, or grossly misleading informatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Military Electronics Of The United States
This article lists types of American military electronic instruments along with brief descriptions of them. Electronic items of this sort are assigned designations according to the Joint Electronics Type Designation System, beginning with the AN/ prefix. They are grouped below by the first designation letter following this prefix. A *AN/AAA-4: Infrared System for F-4H, ACF, Inc., Avion Division. *AN/AAD-4: Forward Looking Infrared Detection Set (FLIR) manufactured by Texas Instruments; used in AC-119G *AN/AAD-5: Infrared IR Reconnaissance Set Manufactured by Honeywell Aerospace Systems; RF-4C *AN/AAD-7: Forward Looking Infrared Detection Set (FLIR) manufactured by Texas Instruments, Inc.; used in AC-130-A, E, H *AN/AAQ-1: Spectrometer *AN/AAQ-2: Aircraft pod-mounted FLIR system, aka "LITENING" *AN/AAQ-3: Aircraft Targeting System, aka "Sniper XR" *AN/AAQ-4: Infrared Countermeasures System; manufactured by Hallicrafters and by Northrop; used in B-66, EB-66C/E, B-52, RF-4C *A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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