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Jackson Bros
Jackson Brothers, commonly known as Jackson Bros, was a firm known for its dominance of the variable capacitor (or 'tuning condenser') market in the early days of radio broadcasting. Founded in 1923 to provide tuning capacitors for the growing home construction market, by the Fillmore family in Lewisham, England, (there never was a pair of people involved who were Jackson brothers!) the firm went on to manufacture a huge variety of the, mostly air-spaced, two or three gang, variable capacitors, that were at the heart of all radio receivers until the invention of the varicap diode, which replaced them, especially in VHF designs, and the frequency-synthesizer front ends that are now found in most radio receivers. History Early beginnings The money for the enterprise came largely from Grandfather Fillmore, who wanted to call the company ‘John Bull and Company’, but other relatives opposed this, and it was settled that Jackson Brothers sounded suitably British. Production of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firm
A company, abbreviated as co., is a Legal personality, legal entity representing an association of people, whether Natural person, natural, Legal person, legal or a mixture of both, with a specific objective. Company members share a common purpose and unite to achieve specific, declared goals. Companies take various forms, such as: * voluntary associations, which may include nonprofit organizations * List of legal entity types by country, business entities, whose aim is generating profit * financial entities and banks * programs or Educational institution, educational institutions A company can be created as a legal person so that the company itself has limited liability as members perform or fail to discharge their duty according to the publicly declared Incorporation (business), incorporation, or published policy. When a company closes, it may need to be Liquidation, liquidated to avoid further legal obligations. Companies may associate and collectively register themselves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Croydon
Croydon is a large town in south London, England, south of Charing Cross. Part of the London Borough of Croydon, a local government district of Greater London. It is one of the largest commercial districts in Greater London, with an extensive shopping district and night-time economy. The entire town had a population of 192,064 as of 2011, whilst the wider borough had a population of 384,837. Historically an ancient parish in the Wallington hundred of Surrey, at the time of the Norman conquest of England Croydon had a church, a mill, and around 365 inhabitants, as recorded in the Domesday Book of 1086. Croydon expanded in the Middle Ages as a market town and a centre for charcoal production, leather tanning and brewing. The Surrey Iron Railway from Croydon to Wandsworth opened in 1803 and was an early public railway. Later 19th century railway building facilitated Croydon's growth as a commuter town for London. By the early 20th century, Croydon was an important industria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Radio
A crystal radio receiver, also called a crystal set, is a simple radio receiver, popular in the early days of radio. It uses only the power of the received radio signal to produce sound, needing no external power. It is named for its most important component, a crystal detector, originally made from a piece of crystalline mineral such as galena. This component is now called a diode. Crystal radios are the simplest type of radio receiver and can be made with a few inexpensive parts, such as a wire for an antenna, a coil of wire, a capacitor, a crystal detector, and earphones (because a crystal set has insufficient power for a loudspeaker). However they are passive receivers, while other radios use an amplifier powered by current from a battery or wall outlet to make the radio signal louder. Thus, crystal sets produce rather weak sound and must be listened to with sensitive earphones, and can receive stations only within a limited range of the transmitter. The rectifying prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Radio
The early history of radio is the history of technology that produces and uses radio equipment, radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting. Discovery In an 1864 presentation, published in 1865, James Clerk Maxwell proposed theories of electromagnetism, with mathematical proofs, that showed that light and predicted that radio and x-rays were all types of electromagnetic waves propagating through free space. Between 1886 and 1888 Heinrich Rudolf Hertz published the results of experiments wherein he was able to transmit electromagnetic waves (radio waves) through the air, proving Maxwell's electromagnetic theory. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west; China, Nepal, and Bhutan to the north; and Bangladesh and Myanmar to the east. In the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives; its Andaman and Nicobar Islands share a maritime border with Thailand, Myanmar, and Indonesia. Modern humans arrived on the Indian subcontinent from Africa no later than 55,000 years ago., "Y-Chromosome and Mt-DNA data support the colonization of South Asia by modern humans originating in Africa. ... Coalescence dates for most non-European populations average to between 73–55 ka.", "Modern human beings—''Homo sapiens''—originated in Africa. Then, int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's List of countries and dependencies by area, sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a Megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and climates, with Deserts of Australia, deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately Early human migrations#Nearby Oceania, 65,000 years ago, during the Last Glacial Period, last i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini. It also completely enclaves the country Lesotho. It is the southernmost country on the mainland of the Old World, and the second-most populous country located entirely south of the equator, after Tanzania. South Africa is a biodiversity hotspot, with unique biomes, plant and animal life. With over 60 million people, the country is the world's 24th-most populous nation and covers an area of . South Africa has three capital cities, with the executive, judicial and legislative branches of government based in Pretoria, Bloemfontein, and Cape Town respectively. The largest city is Johannesburg. About 80% of the population are Black South Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denmark
) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Danish Realm, Kingdom of Denmark , established_title = History of Denmark#Middle ages, Consolidation , established_date = 8th century , established_title2 = Christianization , established_date2 = 965 , established_title3 = , established_date3 = 5 June 1849 , established_title4 = Faroese home rule , established_date4 = 24 March 1948 , established_title5 = European Economic Community, EEC 1973 enlargement of the European Communities, accession , established_date5 = 1 January 1973 , established_title6 = Greenlandic home rule , established_date6 = 1 May 1979 , official_languages = Danish language, Danish , languages_type = Regional languages , languages_sub = yes , languages = German language, GermanGerman is recognised as a protected minority language in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Netherlands
) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherlands , established_title2 = Act of Abjuration , established_date2 = 26 July 1581 , established_title3 = Peace of Münster , established_date3 = 30 January 1648 , established_title4 = Kingdom established , established_date4 = 16 March 1815 , established_title5 = Liberation Day (Netherlands), Liberation Day , established_date5 = 5 May 1945 , established_title6 = Charter for the Kingdom of the Netherlands, Kingdom Charter , established_date6 = 15 December 1954 , established_title7 = Dissolution of the Netherlands Antilles, Caribbean reorganisation , established_date7 = 10 October 2010 , official_languages = Dutch language, Dutch , languages_type = Regional languages , languages_sub = yes , languages = , languages2_type = Reco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Surplus
Military surplus are goods, usually matériel, that are sold or otherwise disposed of when held in excess or are no longer needed by the military. Entrepreneurs often buy these goods and resell them at surplus stores. Usually the goods sold by the military are clothing, equipment, and tools of a nature that is generally useful to the civilian population, as well as embroidered patches, name tags, and other items that can be used for a faux military uniform. Occasionally, vehicles (jeeps, trucks, etc.) will be sold as well. Some military surplus dealers also sell military surplus firearms, spare parts, and ammunition alongside surplus uniforms and equipment. Demand for such items comes from various collectors, outdoorsmen, adventurers, hunters, survivalists, and players of airsoft and paintball, as well as others seeking high quality, sturdy, military issue garb. The goods may be used, or not. Some merchants of surplus goods also sell goods that are privately manufactured in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Research And Development
Research and development (R&D or R+D), known in Europe as research and technological development (RTD), is the set of innovative activities undertaken by corporations or governments in developing new services or products, and improving existing ones. Research and development constitutes the first stage of development of a potential new service or the production process. R&D activities differ from institution to institution, with two primary models of an R&D department either staffed by engineers and tasked with directly developing new products, or staffed with industrial scientists and tasked with applied research in scientific or technological fields, which may facilitate future product development. R&D differs from the vast majority of corporate activities in that it is not intended to yield immediate profit, and generally carries greater risk and an uncertain return on investment. However R&D is crucial for acquiring larger shares of the market through the marketisation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
