|
Satellite Dish
A satellite dish is a dish-shaped type of parabolic antenna designed to receive or transmit information by radio waves to or from a communication satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. C .... The term most commonly means a dish which receives direct-broadcast satellite television from a direct broadcast satellite in geostationary orbit. History Parabolic antennas referred to as "dish" antennas had been in use long before satellite television. The term ''satellite dish'' was coined in 1978 during the beginning of the satellite television industry, and came to refer to dish antennas that send and/or receive signals from communications satellites. Taylor Howard of San Andreas, California, adapted an ex-military dish in 1976 and became the first person to receive s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parabolic Antenna
A parabolic antenna is an antenna that uses a parabolic reflector, a curved surface with the cross-sectional shape of a parabola, to direct the radio waves. The most common form is shaped like a dish and is popularly called a dish antenna or parabolic dish. The main advantage of a parabolic antenna is that it has high directivity. It functions similarly to a searchlight or flashlight reflector to direct radio waves in a narrow beam, or receive radio waves from one particular direction only. Parabolic antennas have some of the highest gains, meaning that they can produce the narrowest beamwidths, of any antenna type. In order to achieve narrow beamwidths, the parabolic reflector must be much larger than the wavelength of the radio waves used, so parabolic antennas are used in the high frequency part of the radio spectrum, at UHF and microwave ( SHF) frequencies, at which the wavelengths are small enough that conveniently-sized reflectors can be used. Parabolic antennas are u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity tow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EchoStar
EchoStar Corporation is an American company, a worldwide provider of satellite communication and Internet services through its Hughes Network Systems and EchoStar Satellite Services business segments. EchoStar is based out of unincorporated Arapahoe County, Colorado. Prior to 2008, it operated the DISH Network service brand, which was spun off as DISH on January 1, 2008. History EchoStar was originally formed in 1980 by its chairman Charles Ergen as a distributor of C band TV systems. In 1987, it applied for a direct broadcast satellite (DBS) license with the Federal Communications Commission and was granted access to orbital slot 119° west longitude in 1992. On December 28, 1995, the firm successfully launched its first satellite, EchoStar I. On March 4, 1996, it established the DISH Network brand name to market its home satellite TV system. On January 2, 2008, the DISH Network business was demerged from the technology and infrastructure side of the business. A split in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bangor, Maine
Bangor ( ) is a city in the U.S. state of Maine and the county seat of Penobscot County. The city proper has a population of 31,753, making it the state's 3rd-largest settlement, behind Portland (68,408) and Lewiston (37,121). Modern Bangor was established in the mid-19th century with the lumber and shipbuilding industries. Lying on the Penobscot River, logs could be floated downstream from the Maine North Woods and processed at the city's water-powered sawmills, then shipped from Bangor's port to the Atlantic Ocean downstream, and from there to any port in the world. Evidence of this is still visible in the lumber barons' elaborate Greek Revival and Victorian mansions and the 31-foot-high (9.4 m) statue of Paul Bunyan. Today, Bangor's economy is based on services and retail, healthcare, and education. Bangor has a port of entry at Bangor International Airport, also home to the Bangor Air National Guard Base. Historically Bangor was an important stopover on the Great Ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bangor Daily News
The ''Bangor Daily News'' is an American newspaper covering a large portion of central and eastern Maine, published six days per week in Bangor, Maine. The ''Bangor Daily News'' was founded on June 18, 1889; it merged with the ''Bangor Whig and Courier'' in 1900. Also known as ''the News'' or ''the BDN'', the paper is published by Bangor Publishing Company, a local family-owned company. It has been owned by the Towle-Warren family for four generations; current publisher Richard J. Warren is the great-grandson of J. Norman Towle, who bought the paper in 1895. Since 2018, it has been the only independently owned daily newspaper in the state. History The ''Bangor Daily News''s first issue was June 18, 1889; the main stockholder in the publishing company was Bangor shipping and logging businessman Thomas J. Stewart. Upon Stewart's death in 1890, his sons took control of the paper, which was originally a tabloid with "some news, but also plenty of gossip, lurid stories and scandals. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PrimeStar
PrimeStar was a U.S. direct broadcast satellite broadcasting company formed in 1991 by a consortium of cable television system operators ( TCI Satellite Entertainment Group, Time Warner Cable, Cox Communications, Comcast and MediaOne) and GE Americom, the satellite arm of General Electric, collectively referred to as the ''PrimeStar Partners''. PrimeStar was the first medium-powered DBS system in the United States but slowly declined in popularity with the arrival of DirecTV in 1994 and Dish Network in 1996. Technology PrimeStar was a medium-powered DBS-style system utilizing FSS technology that used a larger 3-foot (91 cm) satellite dish to receive signals. Broadcast originally in analog, they later converted to digital technology. The system used the DigiCipher 1 system for conditional access control and video compression. The video format was MPEG-2. Primestar's satellite receivers were made by General Instrument. PrimeStar was owned by a consortium of cable tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ku Band
The Ku band () is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz). The symbol is short for "K-under" (originally german: Kurz-unten), because it is the lower part of the original NATO K band, which was split into three bands (Ku, K, and Ka) because of the presence of the atmospheric water vapor resonance peak at 22.24 GHz, (1.35 cm) which made the center unusable for long range transmission. In radar applications, it ranges from 12 to 18 GHz according to the formal definition of radar frequency band nomenclature in IEEE Standard 521–2002. Ku band is primarily used for satellite communications, most notably the downlink used by direct broadcast satellites to broadcast satellite television, and for specific applications such as NASA's Tracking Data Relay Satellite used for International Space Station (ISS) communications and SpaceX Starlink satellites. Ku band satellites are also used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astra 1A
Astra 1A was the first satellite launched and operated by SES (Société Européenne des Satellites), launched in December 1988. During its early days, it was often referred to as the Astra Satellite, as SES only operated one satellite originally. The satellite provided television coverage to Western Europe from 1989 to 2004. Astra 1A was retired and became derelict in December 2004. Channels Among the channels carried in the early years after launch were the entire four channel Sky Television (later British Sky Broadcasting, after the merger with rival British Satellite Broadcasting on the Marcopolo satellite), the services consisted of Sky Channel, Sky News, Sky Movies and Eurosport, the Scandinavian TV3 and TV1000, the German Pro7, Sat.1, RTL plus, 3sat and Teleclub, the Dutch RTL 4 as well as FilmNet, Screensport, MTV Europe, The Children's Channel and Lifestyle. Astra 1A began television broadcasts on 5 February 1989. Until 1998 all of SES' satellites were co-locat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luxembourg
Luxembourg ( ; lb, Lëtzebuerg ; french: link=no, Luxembourg; german: link=no, Luxemburg), officially the Grand Duchy of Luxembourg, ; french: link=no, Grand-Duché de Luxembourg ; german: link=no, Großherzogtum Luxemburg is a small landlocked country in Western Europe. It borders Belgium to the west and north, Germany to the east, and France to the south. Its capital and most populous city, Luxembourg, is one of the four institutional seats of the European Union (together with Brussels, Frankfurt, and Strasbourg) and the seat of several EU institutions, notably the Court of Justice of the European Union, the highest judicial authority. Luxembourg's culture, people, and languages are highly intertwined with its French and German neighbors; while Luxembourgish is legally the only national language of the Luxembourgish people, French and German are also used in administrative and judicial matters and all three are considered administrative languages of the cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuscaloosa, Alabama
Tuscaloosa ( ) is a city in and the seat of Tuscaloosa County in west-central Alabama, United States, on the Black Warrior River where the Gulf Coastal and Piedmont plains meet. Alabama's fifth-largest city, it had an estimated population of 101,129 in 2019. It was known as Tuskaloosa until the early 20th century. It is also known as ''"the Druid City"'' because of the numerous water oaks planted in its downtown streets since the 1840s. Incorporated on December 13, 1819, it was named after Tuskaloosa, the chief of a band of Muskogean-speaking people defeated by the forces of Spanish explorer Hernando de Soto in 1540 in the Battle of Mabila, in what is now central Alabama. It served as Alabama's capital city from 1826 to 1846. Tuscaloosa is the regional center of industry, commerce, healthcare and education for the area of west-central Alabama known as ''West Alabama;'' and the principal city of the Tuscaloosa Metropolitan Statistical Area, which includes Tuscaloosa, Hale and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise Figure
Noise figure (NF) and noise factor (''F'') are figures of merit that indicate degradation of the signal-to-noise ratio (SNR) that is caused by components in a signal chain. These figures of merit are used to evaluate the performance of an amplifier or a radio receiver, with lower values indicating better performance. The noise factor is defined as the ratio of the output noise power of a device to the portion thereof attributable to thermal noise in the input termination at standard noise temperature ''T''0 (usually 290 K). The noise factor is thus the ratio of actual output noise to that which would remain if the device itself did not introduce noise, or the ratio of input SNR to output SNR. The noise ''factor'' and noise ''figure'' are related, with the former being a unitless ratio and the latter being the same ratio but expressed in units of decibels (dB). General The noise figure is the difference in decibels (dB) between the noise output of the actual receiver to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire Mesh
Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm A wire is a flexible strand of metal. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a gauge number. Wires are used to bear mechanical loads, often in the form of wire rope. In electricity and telecommunications signals, a "wire" can refer to an electrical cable, which can contain a "solid core" of a single wire or separate strands in stranded or braided forms. Usually cylindrical in geometry, wire can also be made in square, hexagonal, flattened rectangular, or other cross-sections, either for decorative purposes, or for technical purposes such as high-efficiency voice coils in loudspeakers. Edge-wound coil springs, such as the Slinky toy, are made of special flattened wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Wire Mesh")