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Etymology Of Ham Radio
''Ham radio'' is a popular term for amateur radio, derived from "ham" as an informal name for an amateur radio operator. The use first appeared in the United States during the opening decade of the 20th century—for example, in 1909, Robert A. Morton reported overhearing an amateur radio transmission which included the comment: "Say, do you know the fellow who is putting up a new station out your way? I think he is a ham." However, the term did not gain widespread usage in the United States until around 1920, after which it slowly spread to other English-speaking countries. Etymology At the turn of the 20th century, the terms "ham" and "plug" were used by landline telegraphers to describe an operator "who lacks ability" or who had poor or "ham fisted" skills. By 1881, it had been alleged by telegrapher unions and trade groups that companies were employing "ham" operators who were negligent or incompetent. These unskilled operators were described as either drinking alcohol w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications. The term "amateur" is used to specify "a duly authorised person interested in radioelectric practice with a purely personal aim and without pecuniary interest;" (either direct monetary or other similar reward) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.). The amateur radio service (''amateur service'' and '' amateur-satellite service'') is established by the International Telecommunication Union (ITU) through the Radio Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual station licenses with a unique identifying call sign, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher learning in the United States and one of the most prestigious and highly ranked universities in the world. The university is composed of ten academic faculties plus Harvard Radcliffe Institute. The Faculty of Arts and Sciences offers study in a wide range of undergraduate and graduate academic disciplines, and other faculties offer only graduate degrees, including professional degrees. Harvard has three main campuses: the Cambridge campus centered on Harvard Yard; an adjoining campus immediately across Charles River in the Allston neighborhood of Boston; and the medical campus in Boston's Longwood Medical Area. Harvard's endowment is valued at $50.9 billion, making it the wealthiest academic institution in the world. Endow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications. The term "amateur" is used to specify "a duly authorised person interested in radioelectric practice with a purely personal aim and without pecuniary interest;" (either direct monetary or other similar reward) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.). The amateur radio service (''amateur service'' and '' amateur-satellite service'') is established by the International Telecommunication Union (ITU) through the Radio Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual station licenses with a unique identifying call sign, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammarlund
The Hammarlund Manufacturing Company was founded by Oscar Hammarlund in New York City, New York (state), New York, United States in 1910. When the company was dissolved in 1973, it was among the USA's very oldest producers of radio equipment. History The first Hammarlund plant was a loft operation engaged in radio component manufacturing on Fulton Street (Manhattan), Fulton Street in lower Manhattan, New York City. Their variable capacitor designs quickly became industry standards, and the component's schematic symbol was adopted as the company's logo. In the mid-1920s, Hammarlund formed a partnership called Hammarlund-Roberts Co. specifically to offer kits for AM broadcast radios using Hammarlund parts. The company opened its major manufacturing facility in Mars Hill, North Carolina in 1951. Comet pro receiver When Hammarlund-Roberts went out of business in 1931, Hammarlund Mfg. Co., Inc. entered into the shortwave receiver market with the introduction of the "Comet Pro", the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guglielmo Marconi
Guglielmo Giovanni Maria Marconi, 1st Marquis of Marconi (; 25 April 187420 July 1937) was an Italian inventor and electrical engineer, known for his creation of a practical radio wave-based wireless telegraph system. This led to Marconi being credited as the inventor of radio, and he shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy".Guglielmo Marconi: The Nobel Prize in Physics 1909 . nobelprize.org Marconi was also an entrepreneur, businessman, and founder of The Wireless Telegraph & Signal Company in the |
Edwin Armstrong
Edwin Howard Armstrong (December 18, 1890 – February 1, 1954) was an American electrical engineer and inventor, who developed FM (frequency modulation) radio and the superheterodyne receiver system. He held 42 patents and received numerous awards, including the first Medal of Honor awarded by the Institute of Radio Engineers (now IEEE), the French Legion of Honor, the 1941 Franklin Medal and the 1942 Edison Medal. He was inducted into the National Inventors Hall of Fame and included in the International Telecommunication Union's roster of great inventors. Armstrong attended Columbia University, and served as a professor there for most of his life. Early life Armstrong was born in the Chelsea district of New York City, the oldest of John and Emily (née Smith) Armstrong's three children. His father began working at a young age at the American branch of the Oxford University Press, which published bibles and standard classical works, eventually advancing to the position of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich Rudolf Hertz
Heinrich Rudolf Hertz ( ; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell's equations of electromagnetism. The unit of frequency, cycle per second, was named the "hertz" in his honor.IEC History . Iec.ch. Biography Heinrich Rudolf Hertz was born in 1857 in , then a sovereign state of the , into a prosperous and cultured Hanseati ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modern Electrics
''Modern Electrics'' was a technical magazine for the amateur radio experimenter. The magazine existed between 1908 and 1914. History and profile ''Modern Electrics'' was created by Hugo Gernsback and began publication in April 1908. The magazine was initially intended to provide mail-order information for radio parts and to promote the amateur radio hobby, but it later became a vehicle for technology-based fiction stories. The first fiction appeared in the April, 1911 issue, and the series of 12 installments by Hugo Gernsback would later be published as the science fiction novel ''Ralph 124C 41+''. The circulation for this magazine increased rapidly, starting at 2,000 and increasing to 52,000 in 1911. In 1908, the magazine announced the "wireless registry", a listing of radio owners, their call letters, and the type of equipment they owned and how it was operated. The magazine was sold in 1913, and ceased publication in 1914. It then merged with '' Electrician and Mechanic'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ham Radio (magazine)
''Ham Radio'' (''HR'') was a monthly amateur radio enthusiast magazine published in the United States from November 1967 to June 1990. History and profile ''Ham Radio'' was founded in 1967. The first issue appeared in November 1967. The editor was Jim Fisk W1DTY, who had previously edited 73 Magazine. The publisher was Thorvald "Skip" Tenney. It was based in Greenville, NH. At the 1990 Dayton Hamvention, it was announced that ''Ham Radio'' had been sold to the publishers of ''CQ Amateur Radio''. The magazine published a newsletter, ''HR Report'', founded by Joseph J. Schroeder Jr. The June 1990 issue of ''Ham Radio'' was the 268th and final issue published where subscribers were told of the sale and that they would receive ''CQ'' in the future.''Ham Radio'', June 1990 (issue) The magazine was published in English and drew its subscription base primarily from the United States of America and Canada. Ham Radio Horizons Magazine was a VHF and newcomer emphasis magazine printed b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Call Sign
In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or even cryptographically encoded to disguise a station's identity. The use of call signs as unique identifiers dates to the landline railroad telegraph system. Because there was only one telegraph line linking all railroad stations, there needed to be a way to address each one when sending a telegram. In order to save time, two-letter identifiers were adopted for this purpose. This pattern continued in radiotelegraph operation; radio companies initially assigned two-letter identifiers to coastal stations and stations onboard ships at sea. These were not globally unique, so a one-letter company identifier (for instance, 'M' and two letters as a Marconi sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Congress
The United States Congress is the legislature of the federal government of the United States. It is bicameral, composed of a lower body, the House of Representatives, and an upper body, the Senate. It meets in the U.S. Capitol in Washington, D.C. Senators and representatives are chosen through direct election, though vacancies in the Senate may be filled by a governor's appointment. Congress has 535 voting members: 100 senators and 435 representatives. The U.S. vice president has a vote in the Senate only when senators are evenly divided. The House of Representatives has six non-voting members. The sitting of a Congress is for a two-year term, at present, beginning every other January. Elections are held every even-numbered year on Election Day. The members of the House of Representatives are elected for the two-year term of a Congress. The Reapportionment Act of 1929 establishes that there be 435 representatives and the Uniform Congressional Redistricting Act requires t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Hyman
Albert Salisbury Hyman (1893 - 1972), a Harvard-trained New York cardiologist, together with his brother Charles, constructed in 1930-1932 an electro-mechanical device which was one of the earliest artificial pacemakers. The device was, reportedly, tested on experiment animals and at least one human patient. The first artificial pacemaker was invented by Australian anaesthesiologist Dr Mark C Lidwell, and was used by him to resuscitate a newborn baby at the Crown Street Women's Hospital Crown Street Women's Hospital (now-closed) was once the largest maternity hospital in Sydney, New South Wales, Australia. It was located at 351 Crown Street (corner of Crown and Albion Streets), Surry Hills. The hospital was one of severa ..., Sydney, in 1926. However it was Hyman who used and popularised the term "artificial pacemaker", which remains in use to this day. Aquilina O,A brief history of cardiac pacing", ''Images Paediatr Cardiol'' 27 (2006), pp.17-81. Lidwell did not pate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
