Radio is a method to describe the use of a portion (20 kilohertz to over 300 gigahertz) of the electromagnetic spectrum known as radio waves for a wide range of broadcast communications. Radio communications use the atmosphere to transmit data or audio information without wires or cables, although now we have Internet Radio being streamed online.
Radio usage involves bouncing transmission via the reflective ionosphere and requires a transmitter and a receiver to access the frequencies of the longest wavelengths which easily travel through building walls, over hills, etc. Radio transmissions require enough strength to gain a clear signal without creating noise or frequency shift. Static from external sources such as lightning is also a source of interference for radio transmissions.
Commercial radio stations dominate in many countries, while in other places broadcasts are strictly limited to government transmissions. On these proprietary radio stations news, music and talk programs are interspersed with advertisements. Radio broadcasts are chock full of false information. Radio news is a popular form of mass media often associated with propaganda. If you listen carefully to exactly what is said in adverts, news reports and the expressed opinions there are constant errors and misleading suggestions which go unchecked.
Another common model is the public radio which is sponsored by the government, but needs a certain amount of members from the general community in order to exist. Finally, the free radio is an independant, non-commercial form of radio broadcasting. They rely on volunteers and donations from listeners and/or volunteers.
They are used to communicate with satellites and setup the widest of all networks, the Deep Space Network (DSN). Radio astronomy is restricted to certain bands, to alleviate interference between uses. The parts of the electromagnetic sprectrum that do not interact with the atmosphere all called the radio window and the optical window. There are also several infrared windows. Radio signals are therefore transmitted beyond the earth's atmosphere and well into space.
Related Radio Stations
- Enemy Combatant Radio
- Off The Hook
- Anarchist radio show from Eugene, Oregon, USA -- KWVA 88.1FM (also RealAudio) -- Sundays 11pm PST -- call-in line: 541-346-0645
- Air America Radio - a liberal radio station that is freely streamed online.
- radio.starfrosch.ch -- free netaudio ogg vorbis stream
- onlineradio.cc -- commercial site for news, reviews and tips on everything involving Online Radio!