Radio

Analog Radio

The original conceptualization of radio was as a unified, global system, taking advantage of a universal resource, the segment of the electromagnetic spectrum that became known as radio waves. Its component technologies emerged in an era when cables were being laid to link nations and continents via point-to-point Morse telegraph communication.

The properties of the long (LW), medium (MW), and short (SW) wave bands employed in the earliest organized transmission system, amplitude modulation (AM), were particularly suited to these national, international, and intercontinental uses. National coverage could be achieved with few MW transmitters or fewer LW transmitters; and SW frequencies could carry huge distances around the curvature of the Earth, making them especially suitable for international broadcasting. Of the three wave bands, MW achieved the better overall sound quality and became the preferred wave band for musical entertainment. Thus, most stations known today in popular terminology as AM radio are found on MW.

During the 1960s, AM was joined by a parallel system of frequency modulation (FM). Also known as VHF, from the very high frequency radio wave band it used, it offered higher fidelity than AM and the possibility of transmitting in stereo. However, because VHF carries over shorter distances, it requires more transmitters and is thereby better suited for localized broadcasting, such as across an urban area.

Three main technical factors converged to impel the worldwide adoption of FM: a reinvention of [Page 1431]radio's role in the developed world forced by its usurpation at the heart of the domestic social space by the television set; the opportunity, offered by the invention of the transistor and the mass-produced circuit board, for radio to exit that social space and move into private, more individualized spaces; and the demand thus created for more frequencies to be made available to increase the choice of listening as audiences became more differentiated. Socioeconomic components of this rapid repositioning of the medium were the postwar economic boom, led by the United States, which provided the purchasing power not only for television sets but also for private cars, into which radios could now be fitted as standard. Affluence extended to a wholly new youth market with leisure time to fill and identities to formulate, the expression of which was focused particularly on consumption of the products of a burgeoning transatlantic popular music industry, for which FM music radio provided strong identification and promotion.

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