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Eurosignal
Eurosignal was a European paging system in operation between 1974 and 1997. Transmissions were broadcast between 87.3 and 87.5 MHz in FM, so that their characteristic modulations could be heard on mainstream FM radio receivers. History Eurosignal was introduced in Germany in 1974, France in 1975, and Switzerland in 1985. In France and Switzerland, transmissions were stopped on 31 December 1997 and 1 April 1998, respectively. Operation Utilization A receiver could handle up to four phone numbers. It included an acoustic signal and four optical signals that indicated which of the four numbers called. Eurosignal did not allow other transmissions; the actual four telephone numbers had to be established previously, and use of the signal was limited to telephones. Eurosignal numbers were not listed in a directory in order to limit abuse. Eurosignal had a major advantage over other radiotelephone networks due to its costs, which were about 10% of ordinary phone lines. It also e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paging System
A pager (also known as a beeper or bleeper) is a wireless telecommunications device that receives and displays alphanumeric or voice messages. One-way pagers can only receive messages, while response pagers and two-way pagers can also acknowledge, reply to and originate messages using an internal transmitter. Pagers operate as part of a paging system which includes one or more fixed transmitters (or in the case of response pagers and two-way pagers, one or more base stations), as well as a number of pagers carried by mobile users. These systems can range from a restaurant system with a single low power transmitter, to a nationwide system with thousands of high-power base stations. Pagers were developed in the 1950s and 1960s, and became widely used by the 1980s. In the 21st century, the widespread availability of cellphones and smartphones has greatly diminished the pager industry. Nevertheless, pagers continue to be used by some emergency services and public safety personne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one hertz is the reciprocal of one second. It is named after Heinrich Hertz, Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in metric prefix, multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the photon energy, energy of a photon, via the Planck relation ''E'' = ''hν'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FM Broadcasting
FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is capable of higher fidelity—that is, more accurate reproduction of the original program sound—than other broadcasting technologies, such as AM broadcasting. It is also less susceptible to common forms of interference, reducing static and popping sounds often heard on AM. Therefore, FM is used for most broadcasts of music or general audio (in the audio spectrum). FM radio stations use the very high frequency range of radio frequencies. Broadcast bands Throughout the world, the FM broadcast band falls within the VHF part of the radio spectrum. Usually 87.5 to 108.0 MHz is used, or some portion thereof, with few exceptions: * In the former Soviet republics, and some former Eastern Bloc countries, the older 65.8–74 MHz band ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the ''carrier signal'', with a separate signal called the ''modulation signal'' that typically contains information to be transmitted. For example, the modulation signal might be an audio signal representing sound from a microphone, a video signal representing moving images from a video camera, or a digital signal representing a sequence of binary digits, a bitstream from a computer. The carrier is higher in frequency than the modulation signal. In radio communication the modulated carrier is transmitted through space as a radio wave to a radio receiver. Another purpose is to transmit multiple channels of information through a single communication medium, using frequency-division multiplexing (FDM). For example in cable television which uses FDM, many carrier signals, each modulated with a different television channel, are transported through a sing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unlisted Number
In telephony, an unlisted number (United States, New Zealand), ex-directory number (United Kingdom) silent number, silent line (Australia), or private number (New Zealand, and Canada) is a telephone number that, for a fee, is intentionally not listed in telephone books. Although an unpublished number is not included in the phone book, an unlisted number may be available from the phone company's information operator. When used for residential households they're primarily for privacy and security concerns. When it has personal value it is called a ''vanity'' number.NYTimes: "includes the last four digits" of a person's address. Another form of anomity is being listed with just a first initial, for those with a relatively common family name; sometimes these listings also lack an address. No fee is charged for initially being so-listed. Unlisted numbers as a paid service NYNEX was charging $1.95 per month in 1994; in 1976 the same service was 93 cents monthly. In 1971 ''The New Y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiotelephone
A radiotelephone (or radiophone), abbreviated RT, is a radio communication system for conducting a conversation; radiotelephony means telephony by radio. It is in contrast to '' radiotelegraphy'', which is radio transmission of telegrams (messages), or ''television'', transmission of moving pictures and sound. The term is related to radio broadcasting, which transmit audio one way to listeners. Radiotelephony refers specifically to two-way radio systems for bidirectional person-to-person voice communication between separated users, such as CB radio or marine radio. In spite of the name, radiotelephony systems are not necessarily connected to or have anything to do with the telephone network, and in some radio services, including GMRS, interconnection is prohibited. Design Mode of emission The word ''phone'' has a long precedent beginning with early US wired voice systems. The term means ''voice'' as opposed to telegraph or Morse code. This would include systems fitting in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FM Radio
FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is capable of higher fidelity—that is, more accurate reproduction of the original program sound—than other broadcasting technologies, such as AM broadcasting. It is also less susceptible to common forms of interference, reducing static and popping sounds often heard on AM. Therefore, FM is used for most broadcasts of music or general audio (in the audio spectrum). FM radio stations use the very high frequency range of radio frequencies. Broadcast bands Throughout the world, the FM broadcast band falls within the VHF part of the radio spectrum. Usually 87.5 to 108.0 MHz is used, or some portion thereof, with few exceptions: * In the former Soviet republics, and some former Eastern Bloc countries, the older 65.8–74 MHz band ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplitude Modulation
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to that of the message signal, such as an audio signal. This technique contrasts with angle modulation, in which either the frequency of the carrier wave is varied, as in frequency modulation, or its phase, as in phase modulation. AM was the earliest modulation method used for transmitting audio in radio broadcasting. It was developed during the first quarter of the 20th century beginning with Roberto Landell de Moura and Reginald Fessenden's radiotelephone experiments in 1900. This original form of AM is sometimes called double-sideband amplitude modulation (DSBAM), because the standard method produces sidebands on either side of the carrier frequency. Single-sideband modulation uses bandpass filters to eliminate one of the sidebands and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Modulation
Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and Run-length limited#FM: .280.2C1.29 RLL, computing. In Analog signal, analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the instantaneous frequency deviation, i.e. the difference between the frequency of the carrier and its center frequency, has a functional relation to the modulating signal amplitude. Digital data can be encoded and transmitted with a type of frequency modulation known as frequency-shift keying (FSK), in which the instantaneous frequency of the carrier is shifted among a set of frequencies. The frequencies may represent digits, such as '0' and '1'. FSK is widely used in computer modems, such as fax modems, telephone caller ID systems, garage door openers, and other low-frequency transmissions. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Bartos
Karl Bartos (born 31 May 1952) is a German musician and composer known for his contributions to the electronic band Kraftwerk. Career Karlheinz Bartos was born on 31 May 1952 in Marktschellenberg, Germany, named after his grandfathers Karl and Heinz. He was the drummer in a college band called The Jokers (later The Jolly Jokers in 1975) as Carlos Bartos, around 1965 to 1975. Between 1975 and 1991, he was, along with Wolfgang Flür, a member of the electronic music band Kraftwerk. This lineup of the group remains the most stable and productive yet assembled. He was originally recruited to play on Kraftwerk's US "Autobahn" tour where he changed his name to "Karl", as the band member's names were displayed on stage in neon lighting; "Karlheinz" was deemed too long and thus too expensive by Kraftwerk's front man Ralf Hütter. In addition to his percussion playing, Bartos was credited with songwriting on the ''Man-Machine'', ''Computer World'', and ''Electric Café'' albums and sang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esperanto (Elektric Music Album)
''Esperanto'', released in 1993, was the first studio album by Elektric Music, initially a collaboration of Karl Bartos (formerly of Kraftwerk) and Lothar Manteuffel (formerly of Rheingold), but later only Bartos worked under this name. The project begun after Bartos ended his involvement with Kraftwerk in 1991. The songs "Show Business" and "Kissing the Machine" were co-written with Andy McCluskey of Orchestral Manoeuvres in the Dark, with McCluskey performing vocals on the latter track. "Crosstalk" and "Overdrive" were co-written with Kraftwerk associate Emil Schult, who was also the art director of the cover graphics of the early Elektric Music releases. About half the songs are similar to Kraftwerk, and the others more to contemporary techno. Many Kraftwerk fans were dissatisfied by the techno elements, while others claimed the album was an unexpected masterpiece. Later Kraftwerk releases would, however, feature similar elements. Reception Allmusic AllMusic (previously k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
