Portal:Radio
From Wikipedia, the free encyclopedia
Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of light.
Radio waves are a form of electromagnetic radiation, created whenever a charged object (in normal radio transmission, an electron) accelerates with a frequency that lies in the radio frequency (RF) portion of the electromagnetic spectrum. In radio, this acceleration is caused by an alternating current in an antenna. Radio frequencies occupy the range from a few tens of hertz to a few hundred gigahertz.
Electromagnetic radio spectrum
ELF - SLF - ULF/VF - VLF - LF/LW - MW - HF/SW - VHF - UHF - SHF - EHF
The electromagnetic spectrum is the range of all possible electromagnetic radiation. Also, the "electromagnetic spectrum" (usually just spectrum) of an object is the range of electromagnetic radiation that it emits, reflects, or transmits.
The electromagnetic spectrum, extends from frequencies used in the 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 infinite.
This diagram shows both the position of radio waves in the electromagnetic spectrum as well as how radio waves are used for communication.
BBC Radio 2 is one of the BBC's national radio stations and is the most popular station in the UK. It broadcasts throughout the UK on FM radio between 88 and 91 MHz from its studios in Western House, adjacent to Broadcasting House in central London. Programmes are also relayed on DAB, Sky Digital, Cable TV, Freeview and the Internet.
The station started at 7:00am on September 30, 1967, and succeeded the Light Programme, with some of the Light's music shows transferring to the newly-launched Radio 1. The first show however had actually started at 5.30am (on the Light programme) but continued on with Breakfast Special from Paul Hollingdale as Radio 1 split off.
- People
- Guglielmo Marconi
- H V Kaltenborn, early network radio commentator
- David Sarnoff
- Frank Conrad
- Places & Businesses
- The Marconi Company
- Marconiville (a section of Copiague, New York once named for him)
- The National Broadcasting Company
- XM Satellite Radio
- Things
- AM broadcasting
- Vacuum tube
- Radio network
- Transistor radio
- Amateur radio
John Peel, OBE (30 August 1939 – 25 October 2004), was a British disc jockey, radio presenter, and journalist.
He was one of the original DJs of Radio 1 in 1967 and the only one remaining on Radio 1 at the time of his death. Known for the extraordinary range of his taste in music and the occasional mistakes (such as playing records at the wrong speed) that marked his shows, John Peel was one of the most popular and respected DJs and broadcasters in the world. He was one of the first to play reggae and punk on British radio. His profound influence on alternative rock, pop, and dance music is widely acknowledged. The BBC also released albums of his BBC shows, bands like Joy Division, The Fall, Clash. Live and upfront in the BBC studio.
I, madam, I made radio! So I dared! Am I mad, am I?
- A palindrome by Spider Robinson.
The human brain must continue to frame the problems for the electronic machine to solve.
- –David Sarnoff, radio pioneer (1891-1971)
Radio is a medium of entertainment which permits millions of people to listen to the same joke at the same time, and yet remain lonesome."
- -T. S. Eliot
Radio is the theater of the mind; television is the theater of the mindless.
- -Steve Allen
It's not true that I had nothing on. I had the radio on.
- -Marilyn Monroe
