Radio
From RationalWiki
Radio is like television without the amusing graphics. Or an internet that does not require reading ability.
It involves the broadcasting of coherent audio signals encoded into specified frequencies of electromagnetic waves, which can then be intercepted with an appropriate antenna and tuned oscillating circuit, and decoded, amplified, and listened to via loudspeakers of your choice.
The simplest receivers are all in one small package, and often run on batteries. The most complex involve many separate components, all carefully selected for their ability to produce the highest possible quality listening experience. There are also radios built to receive a large number of frequency bands.
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[edit] Radio in the U.S.
In the United States, FM, or "frequency modulated" radio, with a clumsy provision for stereo, or two channel reproduction, is usually used to transmit music; whereas AM, or "amplitude modulated" radio is nowadays the province of various genres of "talk radio".
The FM band is noticeably further divided into vague sections, with various public radio, college radio and religious radio stations found in the 88-92 MHz range, while popular dance hits can usually be found promoting their beats at 105 - 107 MHz. Rock stations are usually at 94 - 97, and country stations in the fat middle of the dial from 98 - 103.[citation needed] These are not hard and fast regulations, except that stations near the middle of the band will experience better reception due to the antenna's lengths being a compromise that favors it.
[edit] Cooler stuff
In addition to these large scale, usually commercial operating bands, there are parts if the spectrum reserved for amateurs of all stripes, including "ham" radio operators and those using "Citizen's Band" (CB) radio. Both of these bands permit reception and low power broadcast. Citizen's Band is the coolest because it is used by truck drivers ("big, burly..." sorta like loggers. WOOF!) and was one of the more memorable fads of the mid 1970s.
Shortwave refers to the spectrum above the AM (medium wave) and below the CB radio and television channel 2-6 bands; about half of the "ham" bands are located within the shortwave spectrum, as well as all sorts of other fun and weird stuff, including commercial and government broadcasts which can be received internationally.
For the terminally cool, one can build simple yet high powered AM radio transmitters from nothing more than several meters of common copper wire and some extremely butch capacitors. Such transmitters have the dual properties of operating at a sufficient voltage to kill you stone dead if mishandled, and being highly illegal due to the broad spectrum RF noise they produce.More detail.
The telecom industry currently wants to get their hands on as much of the radio spectrum as they can so they can gobble it up for cellular phone use and trunked multifrequency radio systems for the cops, which are completely unnecessary but a financial boon to the telecom industry who have convinced public safety agencies they need those new trunked systems in teh name of homeland security. This is why broadcast TV no longer goes up to channel 83. It is also why analog TV broadcasting is about to be phased out by government mandate, forcing you to have to buy a (made in China) converter box or a new (made in China) digital TV to replace your (union made in the USA) analog TV that has served you so well for the last 19 years. They also have their eye on grabbing as much of the ham radio spectrum as they can, if not for the ARRL which is the only thing holding them back in that area.
[edit] R.O.W.
Foreign radios are as strange as foreign languages, with bands labeled "MW", "LW", etc., which make no sense and don't pick up anything useful in America.
