|
Comrex
Comrex is an American corporation that designs and manufactures equipment for radio and television broadcasting. Beginnings Comrex was founded in 1961 by John Cheney, a broadcast engineer. His mission, as outlined in Comrex's inaugural press release, is "to apply advanced state of the art knowledge and techniques to the production of high quality, practical equipment which can be operated by non-technical personnel.” Throughout the 1960s and 1970s, Comrex developed audio products for the television market: * 1968 – Cheney develops Models 7035 and 7040, receivers for wireless microphone systems. * 1973 – The 450 RA/TA wireless microphone system, designed for TV news, is the first to enable reporters to move more than 1000 feet from the camera. * 1975 – The Comrex wireless cue system, composed of the CTA cue transmitter and the CRA (now LPQRA) receiver, enables field reporters and producers to hear production audio and instructions, without a wired connection to a news ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Services Digital Network
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work on the standard began in 1980 at Bell Labs and was formally standardized in 1988 in the CCITT "Red Book". By the time the standard was released, newer networking systems with much greater speeds were available, and ISDN saw relatively little uptake in the wider market. One estimate suggests ISDN use peaked at a worldwide total of 25 million subscribers at a time when 1.3 billion analog lines were in use. ISDN has largely been replaced with digital subscriber line (DSL) systems of much higher performance. Prior to ISDN, the telephone system consisted of digital links like T1/ E1 on the long-distance lines between telephone company offices and analog signals on copper telephone wires to the customers, the " last mile". At the time, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devens, Massachusetts
Devens is a regional enterprise zone and census-designated place in the towns of Ayer and Shirley (in Middlesex County) and Harvard (in Worcester County) in the U.S. state of Massachusetts. It is the successor to Fort Devens, a military post that operated from 1917 to 1996. The population was 1,840 at the 2010 census. Demographics History The area itself is named after jurist and Civil War general Charles Devens. In 2011, the CDP tried to secede from Ayer, Shirley, and Harvard and become the 352nd town in the Commonwealth of Massachusetts but failed the vote. Some residents are still looking to secede to become a town. Military Use The area operated as Fort Devens from 1917 to 1996. The Fort's sitting was due primarily to its location at a major hub of the rail network in New England. Since 1917, a formerly sleepy area was developed into a fort that was later redeveloped into the industrial area of Devens. Federal Medical Center, Devens was established as a federal prison ... [...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] |
Television Broadcasting
A television network or television broadcaster is a telecommunications network for distribution of television program content, where a central operation provides programming to many television stations or pay television providers. Until the mid-1980s, television programming in most countries of the world was dominated by a small number of terrestrial networks. Many early television networks (such as NBC, the ABC, or the BBC) evolved from earlier radio networks. Overview In countries where most networks broadcast identical, centrally originated content to all of their stations and where most individual television transmitters therefore operate only as large " repeater stations", the terms "television network", "television channel" (a numeric identifier or radio frequency) and "television station" have become mostly interchangeable in everyday language, with professionals in television-related occupations continuing to make a differentiation between them. Within the industry, a ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plain Old Telephone Service
Plain old telephone service (POTS), or plain ordinary telephone system, is a retronym for voice-grade telephone service employing analog signal transmission over copper loops. POTS was the standard service offering from telephone companies from 1876 until 1988 in the United States when the Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) was introduced, followed by cellular telephone systems, and voice over IP (VoIP). POTS remains the basic form of residential and small business service connection to the telephone network in many parts of the world. The term reflects the technology that has been available since the introduction of the public telephone system in the late 19th century, in a form mostly unchanged despite the introduction of Touch-Tone dialing, electronic telephone exchanges and fiber-optic communication into the public switched telephone network (PSTN). Characteristics POTS is characterized by several aspects: *Bi-directional (full duplex) comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP Codec
IP codecs are used to send video or audio signals over an IP network such as the Internet. The initials "IP" here stand for "Internet Protocol", while the term "codec" is short for "encoder/decoder" or "compressor/decompressor". IP video codecs IP video codecs are used widely in security and broadcast applications to send video between two locations. Video codecs use compression algorithms to send good video quality at substantially lower bit rates than uncompressed signals. Broadcast applications often use MPEG-2 and H.264/MPEG-4 AVC standards for video compression. The EBU is working on a minimum set of common standards for real-time video over IP transmissions. The recommended standards and protocols are designed to ensure compatibility between different codecs and provide adequate high quality transmissions. IP audio codecs IP audio codecs are used to send broadcast quality audio over IP from remote broadcast locations to radio and television studios around the globe. IP cod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications Equipment Vendors
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that feasible with the human voice, but with a similar scale of expediency; thus, slow systems (such as postal mail) are excluded from the field. The transmission media in telecommunication have evolved through numerous stages of technology, from beacons and other visual signals (such as smoke signals, semaphore telegraphs, signal flags, and optical heliographs), to electrical cable and electromagnetic radiation, including light. Such transmission paths are often divided into communication channels, which afford the advantages of multiplexing multiple concurrent communication sessions. ''Telecommunication'' is often used in its plural form. Other examples of pre-modern long-distance communication included audio messages, such as coded drumbea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics Companies Established In 1961
The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering, which only uses passive effects such as resistance, capacitance and inductance to control electric current flow. Electronics has hugely influenced the development of modern society. The central driving force behind the entire electronics industry is the semiconductor industry sector, which has annual sales of over $481 billion as of 2018. The largest industry sector is e-commerce, which generated over $29 trillion in 2017. History and development Electronics has hugely influenced the development of modern society. The identification of the electron in 1897, along with the subsequent invention of the vacuum tube which could amplify and rectify small el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
