A Citizen's Band (CB) radio or CB transceiver is a two-way communications device that is operated by individuals on approved frequencies in various nations. The technology originated in the United States in 1945 when the Federal Communications Commission (FCC) officially approved a band of frequencies for CB transmissions. By the 1960s, the CB had become a popular addition to the equipment of most long distance truckers who transported goods across the nation, and was also spreading to other businesses and countries.
Originally, the frequencies allotted to CB transceiver equipment were the 460- to 470-megahertz UFH band, but this was changed to the 27-megahertz, 11-meter band in the 1970s in the US, and similar frequency ranges are used in other nations. Using a CB radio in most cases does not require a broadcasting license. It is open to personal or business use and is based on a simplex system, where a unit can transmit only when no one else is, and cannot transmit and receive signals at the same time. The European Union in general, Canada, and the UK all have similar systems. Asian nations such as Indonesia and Malaysia also have them, and Australia adopted the same US 40-channel 27-megahertz band in 1980.
Societal changes in the United States in the early 1970s propelled the purpose of a CB transceiver to greater heights, when an Arab oil embargo from October 1973 to March 1974 made fuel supplies expensive and scarce in the US. This led to a an increased level of CB transceiver air traffic among truckers and other small businesses that relied on fuel to survive. They shared the location of open fuel stations, as well as speed traps by law enforcement, as a reduced speed limit on federal highways in 1973 also went into effect to promote conservation. Trucking businesses, which are responsible for most of the movement of goods throughout the United States, are dependent on rapid transit and readily available fuel to make a profit.
Types of transceivers had become more portable by the late 1960s and early 1970s, as advances in solid state electronics meant that they could be installed in automobiles, on motorcycles, and more. Advances in technology in recent years have also reduced the use of the CB transceiver, as it is replaced by more convenient methods of communication, such as cellular phones and free wireless Internet services. The simplex design of the CB transceiver does not work well when there is heavy traffic on a frequency, as only one person can talk at a time. This has led to a decline in using a CB transceiver, though most over-the-road truckers still have active units installed in their cabs for emergencies.