Portal:Radio
The Radio Portal  Welcome to Wikipedia's portal for Radio. Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. It does not require a medium of transport. Information is carried by systematically changing (modulating) some property of the radiated waves, such as their amplitude or their frequency. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. The word 'radio' is used to describe this phenomenon, and television, radio, and cell phone transmissions are all classed as radio frequency emissions. Modulation is the process where speech, music and the like are impressed onto the carrier wave of a transmission. Detection or demodulation is the reverse proces which takes place in a receiver. The speech, music etc is recovered and may then be amplified and applied to an ear piece or a loud speaker. The most common forms of modulation are Amplitude Modulation (AM) and Frequency Modulation (FM) both of which use different modulation and detection circuits. Cell phones, digital radio and digital television use more complex modulation and demodulation systems. The simplest AM receiver is the Crystal Set or Crystal Radio. Demodulation is achieved by a semiconductor diode. One of the earliest forms of detection consisted of a thin copper wire in contact with a small chunk of Galena Rock. Adequate signals could be heard in headphones for up to 50 km with simple arrangements. Selected article The electromagnetic spectrum, extends from frequencies used into electric power grid (at the long-wavelength end) to gamma radiation (at the short-wavelength end), covering wavelengths from thousands of kilometres down to fractions of the size of an atom. It is commonly said that EM waves beyond these limits are uncommon, although this is not actually true. The 22-year sunspot cycle, for instance, produces radiation with a period of 22 years, or a frequency of 1.4*10-9 Hz. At the other extreme, photons of arbitrarily high frequency may be produced by colliding electrons with positrons at appropriate energy. 1024 Hz photons can be produced today with man-made accelerators. In our universe the short wavelength limit is likely to be the Planck length, and the long wavelength limit is the size of the universe itself (see physical cosmology), though in principle the spectrum is it infinite. Selected image This photograph shows the receivers and transceivers used in an amateur radio station. Amateur radio is a hobby in which enthusiasts purchase or build their own equipment and use radio for their own enjoyment. Radio amateurs are licensed to use frequencies in a large number of narrow bands throughout the radio spectrum. Photo Credit: User:NX1Z Selected stationBBC Local Radio is the BBC's regional radio service for England and the Channel Islands, consisting of 40 stations. Initially, stations had to be co-funded by the BBC and local authorities, which only some Labour-controlled areas proved willing to do. Radio Leicester was the first to launch on 8 November 1967, followed by Sheffield, Merseyside and Nottingham. By the early 1970s, the local authority funding requirement was dropped, and stations spread across the country; many city-based stations later expand their remit to cover an entire county. Today, stations are asked to target their coverage to Dave and Sue, two fictional fifty-five-year-olds. CategoriesThe following are categories relating to radio: Radio by country • Radio networks • Radio formats • Radio stations • Radio people • Radio programs • History of radio • Radio drama • Amateur radio • Pirate radio • Types of radios • Radio technology • Radio frequency receivers • Radio hobbies • Radio logos • Radio writers • Years in radio • Military radio systems • Radio astronomy • SETI • Radio-related lists • Radio stubs Radio listsThe following are lists relating to radio: 97.3 FM • 105.9 FM • BBC Radio 4 programmes • Dad's Army radio episodes • Fictional radio stations • FM broadcasting in Egypt • High school radio • Indie radio stations • Q92 • Q107 • Radio Stations of the BBC • Reith Lecture • Sirius Satellite Radio stations • This American Life episodes • UK radio programmes • World's oldest radio stations • XM Satellite Radio channels • Z103 • AOL Radio • Angel Radio • List of radio stations in Kosovo Selected quote
Selected biographyHoward Stern (born Howard Allen Stern on January 12, 1954) is an American radio and TV personality, media mogul, humorist, actor, and author. He is best known for his national radio show, which for many years was syndicated on FM radio stations (and a few AM stations) throughout the United States until his last terrestrial radio broadcast on December 16, 2005. He began broadcasting on the subscription-based Sirius satellite radio service on January 9, 2006. The self-proclaimed "King of All Media" (a humorous reference to Michael Jackson's appellation "The King of Pop") has been dubbed a shock jock for his highly controversial use of scatological, sexual and racial humor. Stern has said that the show was never about shocking people, but primarily intended to offer his honest opinions on a gamut of issues (ranging from world affairs to problems among his own staff). Though controversial, he is one of the highest-paid radio personalities in the United States and the most fined personality in radio broadcast history. Related portalsWikiProjects
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