page_title: Citizens band radio
section_title: Origins
hierarchical_section_title: Citizens band radio / History / United States / Origins
caption_attribution_description: English: QSL card from a US CB operator KHI-6261, in South Lebanon, Ohio.
context_page_description: Citizens band radio, used in many countries, is a land mobile radio system, a system allowing short-distance person-to-person bidirectional voice communication between individuals, using two way radios operating on 40 channels near 27 MHz in the high frequency band. Citizens band is distinct from other personal radio service allocations such as FRS, GMRS, MURS, UHF CB and the Amateur Radio Service. In many countries, CB operation does not require a license, and it may be used for business or personal communications. Like many other land mobile radio services, multiple radios in a local area share a single frequency channel, but only one can transmit at a time. The radio is normally in receive mode to receive transmissions of other radios on the channel; when users want to talk they press a "push to talk" button on their radio, which turns on their transmitter. Users on a channel must take turns talking. Transmitter power is limited to 4 watts in the US and the EU. CB radios have a range of about 3 miles to 20 miles depending on terrain, for line of sight communication; however, various radio propagation conditions may intermittently allow communication over much greater distances.
context_section_description: The citizens band radio service originated in the United States as one of several personal radio services regulated by the Federal Communications Commission (FCC). These services began in 1945 to permit citizens a radio band for personal communication (e.g., radio-controlled model airplanes and family and business communications). In 1948, the original CB radios were designed for operation on the 460–470 MHz UHF band. There were two classes of CB radio: "A" and "B". Class B radios had simpler technical requirements, and were limited to a smaller frequency range. Al Gross established the Citizens Radio Corporation during the late 1940s to manufacture class B handhelds for the general public. Originally designed for use by the public sector, the Citizens Radio Corporation went on to sell over 100,000 units, primarily to farmers and the US Coast Guard.
  Ultra-high frequency (UHF) radios, at the time, were neither practical nor affordable for the average consumer. On 11 September 1958 CB service class D was created on 27 MHz, and this band became what is popularly known today as "Citizens Band". Only 23 channels were available at the time; the first 22 were taken from the former amateur radio service 11 meter band, and channel 23 was shared with radio-controlled devices. Some hobbyists continue to use the designation "11 meters" to refer to the Citizens Band and adjoining frequencies. Part 95 of the Code of Federal Regulations regulates the class D CB service, on the 27 MHz band, since the 1970s and continuing today. Most of the 460–470 MHz band was reassigned for business and public-safety use; CB Class A is the forerunner of the General Mobile Radio Service (GMRS). CB Class B is a more distant ancestor of the Family Radio Service. The Multi-Use Radio Service is another two-way radio service in the VHF high band. An unsuccessful petition was filed in 1973 to create a CB Class E service at 220 MHz, (part of the amateur radio 1¼ m band at the time) which was opposed by amateur radio organizations and others. There are several other classes of personal radio services for specialized purposes (such as remote control devices).
  During the 1960s, the service was popular among small businesses (e.g., electricians, plumbers, carpenters), truck drivers and radio hobbyists. By the late 1960s, advances in solid-state electronics allowed the weight, size, and cost of the radios to fall, giving the public access to a communications medium previously only available to specialists. CB clubs were formed; a CB slang language evolved alongside 10-codes, similar to those used in emergency services.
caption: A QSL card issued by a US CB station in 1963.
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