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Geoffrey G. Gouriet
Geoffrey George Gouriet C.B.E., M.I.E.E (9 April 1916 – 1973) joined the Drive Section of the Transmitters Department of the BBC in 1937,''Electronics and Power'', Vol 10, #10, p. 358. I.E.E 1964, TK1.I22. and in 1937/38 he was the inventor of a high stability crystal-controlled variant of the Colpitts oscillator. With the outbreak of war imminent, his circuit was put to immediate use by the BBC to drive its Medium Wave broadcast transmitters, allowing the implementation of Britain's wartime single-frequency synchronised radio services from multiple transmitters. This was a technique adopted to try to prevent the Luftwaffe conducting air raids on British cities using BBC transmitters for navigation. Due to wartime security measures, Gouriet's oscillator design was kept secret until after World War II. Meanwhile, the same circuit was independently discovered by James Kilton Clapp of the USA, and published by him in 1948. Gouriet's oscillator is usually known as the Clapp oscillato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order Of The British Empire
The Most Excellent Order of the British Empire is a British order of chivalry, rewarding contributions to the arts and sciences, work with charitable and welfare organisations, and public service outside the civil service. It was established on 4 June 1917 by King George V and comprises five classes across both civil and military divisions, the most senior two of which make the recipient either a knight if male or dame if female. There is also the related British Empire Medal, whose recipients are affiliated with, but not members of, the order. Recommendations for appointments to the Order of the British Empire were originally made on the nomination of the United Kingdom, the self-governing Dominions of the Empire (later Commonwealth) and the Viceroy of India. Nominations continue today from Commonwealth countries that participate in recommending British honours. Most Commonwealth countries ceased recommendations for appointments to the Order of the British Empire when they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colpitts Oscillator
A Colpitts oscillator, invented in 1918 by American engineer Edwin H. Colpitts, is one of a number of designs for LC oscillators, electronic oscillators that use a combination of inductors (L) and capacitors (C) to produce an oscillation at a certain frequency. The distinguishing feature of the Colpitts oscillator is that the feedback for the active device is taken from a voltage divider made of two capacitors in series across the inductor. Overview The Colpitts circuit, like other LC oscillators, consists of a gain device (such as a bipolar junction transistor, field-effect transistor, operational amplifier, or vacuum tube) with its output connected to its input in a feedback loop containing a parallel LC circuit (tuned circuit), which functions as a bandpass filter to set the frequency of oscillation. The amplifier will have differing input and output impedances, and these need to be coupled into the LC circuit without overly damping it. A Colpitts oscillator uses a pair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Wave
Medium wave (MW) is the part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. The spectrum provides about 120 channels with more limited sound quality than FM stations on the FM broadcast band. During the daytime, reception is usually limited to more local stations, though this is dependent on the signal conditions and quality of radio receiver used. Improved signal propagation at night allows the reception of much longer distance signals (within a range of about 2,000 km or 1,200 miles). This can cause increased interference because on most channels multiple transmitters operate simultaneously worldwide. In addition, amplitude modulation (AM) is often more prone to interference by various electronic devices, especially power supplies and computers. Strong transmitters cover larger areas than on the FM broadcast band but require more energy and longer antennas. Digital modes are possible but have not reached momentum yet. MW was the main radio ban ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luftwaffe
The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabteilung'' of the Imperial Navy, had been disbanded in May 1920 in accordance with the terms of the 1919 Treaty of Versailles which banned Germany from having any air force. During the interwar period, German pilots were trained secretly in violation of the treaty at Lipetsk Air Base in the Soviet Union. With the rise of the Nazi Party and the repudiation of the Versailles Treaty, the ''Luftwaffe''s existence was publicly acknowledged on 26 February 1935, just over two weeks before open defiance of the Versailles Treaty through German rearmament and conscription would be announced on 16 March. The Condor Legion, a ''Luftwaffe'' detachment sent to aid Nationalist forces in the Spanish Civil War, provided the force with a valuable testing grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Kilton Clapp
James Kilton Clapp (December 30, 1897 – 1965) was an American electrical engineer who worked for General Radio Corporation. He was born in Denver, Colorado and graduated from Massachusetts Institute of Technology in 1923, obtaining a master's degree there in 1926. He taught at MIT and then joined General Radio Corporation in 1928, until his retirement in 1957. He became a member of the IRE in 1928 and in 1933 was named "Fellow". Several of Clapp's inventions became the basis of General Radio products. He invented a quartz-crystal oscillator frequency standard in 1930, and patented a temperature control oven for crystal oscillators. Clapp's name is best known in the field of electronics for his description in 1948 of an improved form of Colpitts oscillator known as the Clapp oscillator The Clapp oscillator or Gouriet oscillator is an LC electronic oscillator that uses a particular combination of an inductor and three capacitors to set the oscillator's frequency. LC oscillator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clapp Oscillator
The Clapp oscillator or Gouriet oscillator is an LC electronic oscillator that uses a particular combination of an inductor and three capacitors to set the oscillator's frequency. LC oscillators use a transistor (or vacuum tube or other gain element) and a positive feedback network. The oscillator has good frequency stability. History The Clapp oscillator design was published by James Kilton Clapp in 1948 while he worked at General Radio. According to Czech engineer Jiří Vackář, oscillators of this kind were independently developed by several inventors, and one developed by Gouriet had been in operation at the BBC since 1938. Circuit The Clapp oscillator uses a single inductor and three capacitors to set its frequency. The Clapp oscillator is often drawn as a Colpitts oscillator that has an additional capacitor () placed in series with the inductor. The oscillation frequency in Hertz (cycles per second) for the circuit in the figure, which uses a field-effect transisto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBC Research & Development
BBC Research & Development is the technical research department of the BBC. Function It has responsibility for researching and developing advanced and emerging media technologies for the benefit of the corporation, and wider UK and European media industries, and is also the technical design authority for a number of major technical infrastructure transformation projects for the UK broadcasting industry. Structure BBC R&D is part of the wider BBC Design & Engineering, and is led by Jatin Aythora, Director, Research & Development. In 2011, the North Lab moved into MediaCityUK in Salford along with several other departments of the BBC, whilst the South Lab remained in White City in London. History In April 1930 the Development section of the BBC became the Research Department. The department as it stands today was formed in 1993 from the merger of the BBC Designs Department and the BBC Research Department. From 2006 to 2008 it was known as Research and Innovation but has sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Lamb Cullen
Alexander Lamb Cullen, (30 April 1920 – 27 December 2013) was a British electrical engineer. Career and research Cullen served as the Head of Department of Electronic and Electrical Engineering at University College London where he held the Pender Chair, from 1967 to 1980. In 1988 he published his book ''Modern Radio Science'' and a biography of Harold Barlow. Awards and honours He was elected a Fellow of the Royal Society (FRS) in 1977 and awarded their Royal Medal in 1984 in recognition of his many distinguished contributions to microwave engineering, both theoretical and experimental, and in particular for research on microwave antennae. The same year he was awarded the Faraday Medal of the Institute of Electrical Engineers. He also the same year delivered the Clifford Paterson Lecture to the Royal Society on "Microwaves: the art and the science". He was appointed Order of the British Empire The Most Excellent Order of the British Empire is a British order of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Institution Christmas Lectures
The Royal Institution Christmas Lectures are a series of lectures on a single topic each, which have been held at the Royal Institution in London each year since 1825, missing 1939–1942 because of the Second World War. The lectures present scientific subjects to a general audience, including young people, in an informative and entertaining manner. Michael Faraday initiated the Christmas Lecture series in 1825, at a time when organised education for young people was scarce. Faraday presented nineteen series of lectures in all. History The Royal Institution's Christmas Lectures were first held in 1825, and have continued on an annual basis since then except for four years during the Second World War. They have been hosted each year at the Royal Institution itself, except in 1929 and between 2005–2006, each time due to refurbishment of the building. They were created by Michael Faraday, who later hosted the lecture season on nineteen occasions. The Nobel laureate Sir William B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1916 Births
Events Below, the events of the First World War have the "WWI" prefix. January * January 1 – The British Empire, British Royal Army Medical Corps carries out the first successful blood transfusion, using blood that had been stored and cooled. * January 9 – WWI: Gallipoli Campaign: The last British troops are evacuated from Gallipoli, as the Ottoman Empire prevails over a joint British and French operation to capture Constantinople. * January 10 – WWI: Erzurum Offensive: Russia defeats the Ottoman Empire. * January 12 – The Gilbert and Ellice Islands Colony, part of the British Empire, is established in present-day Tuvalu and Kiribati. * January 13 – WWI: Battle of Wadi (1916), Battle of Wadi: Ottoman Empire forces defeat the British, during the Mesopotamian campaign in modern-day Iraq. * January 29 – WWI: Paris is bombed by German Empire, German zeppelins. * January 31 – WWI: An attack is planned on Verdun, France. February * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1973 Deaths
Events January * January 1 - The United Kingdom, the Republic of Ireland and Denmark enter the European Economic Community, which later becomes the European Union. * January 15 – Vietnam War: Citing progress in peace negotiations, U.S. President Richard Nixon announces the suspension of offensive action in North Vietnam. * January 17 – Ferdinand Marcos becomes President for Life of the Philippines. * January 20 – Richard Nixon is sworn in for a second term as President of the United States. Nixon is the only person to have been sworn in twice as President ( 1969, 1973) and Vice President of the United States ( 1953, 1957). * January 22 ** George Foreman defeats Joe Frazier to win the heavyweight world boxing championship. ** A Royal Jordanian Boeing 707 flight from Jeddah crashes in Kano, Nigeria; 176 people are killed. * January 27 – U.S. involvement in the Vietnam War ends with the signing of the Paris Peace Accords. February * February 8 – A militar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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