As World Radio Day, which marks the anniversary of the first broadcast by UN Radio in 1946, is celebrated every 13 February, it is worth recalling the IEC’s central role in the technical development of radio broadcasting.
Ubiquitous and reaching all parts of the world
Radio remains to these days one of the most widespread and popular communication medium in spite of the growing popularity of television and, more recently, of the Internet. Unlike these it doesn’t require expensive equipment and, since the introduction of transistor radios in the mid-1950s, can even be independent from access to an electricity grid, a major benefit for millions in many countries.
Radio is experiencing a revival as more and more devices, such as car radios, portable audio players and mobile phones are designed to receive it, and as digital radio widens its reach.
IEC Standards central to development of radio equipment
Radio depends entirely on electricity as a source of power for transmission and reception, and on electrical and electronic components for its broadcasting and receiving equipment. A multitude of IEC TCs (Technical Committees) and SCs (Subcommittees) develop International Standards for such components and systems.
In 1926, shortly after radio broadcasting was introduced, the IEC created TC 12: Radiocommunications.
Nowadays, IEC standardization work for radio broadcasting and receiving equipment is carried out by TC 100: Audio, video and multimedia systems and equipment, TC 103: Transmitting equipment for radiocommunication, and TC 108: Safety of electronic equipment within the field of audio/video, information technology and communication technology.
Radio reception can be subject to interference from a variety of sources, which include electrical equipment.
As early as the 1930s it was decided to deal with the subject of radio interference at an international level. Following an ad hoc conference of interested international organizations held in Paris in 1933, CISPR (International Special Committee on Radio Interference) was created and first met in 1934.
CISPR is an organization within the IEC that brings together experts who come from radio regulatory authorities, test houses, manufacturers, other IEC committees, and organizations which are not associated with IEC National Committees.
The initial frequency range considered to deal with radio interference extended from 150 kHz to 30 MHz, therefore including long-, medium- and short-waves.
CISPR work led to the reduction in interference to radio (and later TV) broadcasts by the definition of limits from domestic, industrial and commercial appliances, as well as from ignition systems in the automotive field and fluorescent lighting fixtures.