Webcast Radio

Shortwave Radio

The development of shortwave radio broadcasting traces its roots to early radio experimenters known as hams. These amateur shortwave radio operators would utilize their radio equipment to communicate with each other, transmitting on any frequency they chose.

Several objectives supported the use of shortwave radio for broadcasting purposes in the early days of radio. Most important was basic technical experimentation: determining how far and how reliably signals could be transmitted and at what times and frequencies. Another objective was to cover remote areas not easily reached by limited-range AM radio signals thus providing news and entertainment to those not otherwise served by radio.

A third objective was to serve as a unifying national force. In the US, broadcasting was essentially a private function. The government set technical standards and provided regulation on matters such as frequency, power, and hours of operation but the shortwave radio broadcasts themselves were private enterprises.

The relaying of programs from one country to another by shortwave radio for rebroadcasting on local AM radio frequencies was another objective of early shortwave broadcasting. Although in theory such relays would provide a means of enriching local programming. The relays were usually small in scale until World War II when rebroadcasting took on a propaganda objective.

After the war, the growth of shortwave radio broadcasting was largely a product of the propaganda needs of Cold War antagonists and the desire of many countries to have a place at the international broadcasting table and a voice that served national pride. Shortwave radio broadcasting maintained its usual shape however international services presented by government broadcasters in the listener's own language at convenient times and on multiple frequencies so as to provide the best reception in the target zone.

Although never as prevalent on the shortwave radio bands as the government broadcasters, private stations use shortwave as well. In some cases these are private AM radio stations simulcasting on shortwave radio simply to increase their range. Private religious organizations have also used shortwave radio as a means of transmitting their message worldwide. Most private shortwave radio broadcasting in the US is by religious stations.

Although its roots can be traced as far back as the Spanish Civil War, jamming became a serious problem in international shortwave radio broadcasting after Word War II. The international transmission of noise on or near the frequency of an offending station by a transmitter located in the listener's area was routine in communist countries and was effective in preventing the reception of unwanted broadcasts.

One response to jamming was to broadcast on multiple frequencies in hopes that one would get through. This led to more jamming and rendered significant parts of the shortwave radio broadcast bands useless. Fortunately jamming basically ceases in the 1980s.