Stations in the CB service are limited to a power output of 4 watts, with additional restrictions on antenna height. Most stations use AM, but a single sideband (SSB) is allowed with a peak effective power of 12 watts output. In some countries, FM is used. CB radios are used for both fixed and mobile communication over relatively short distances. In the United States, communication at ranges greater than 250 kilometers is prohibited by law.

     Prior to the rapid growth of the CB service in the United States during the early 1970s, a Class D license was required, and a small fee had to be paid. A federal court decision made the fees illegal. Faced with no revenue to support the administration of issuing licenses, the FCC issued a blanket authorization allowing the CB service to operate within the constraints of 28 simple rules.

In the early days of the CB service, the FCC was divided into 18 regions. So, for example, call signs beginning with 18W indicated a station was somewhere in region 18 (region 18's central office was in Chicago, for example). The number of applications for CB licenses soon exhausted that call sign format. New call signs were issued that followed an alphabetical-numerical mix and were issued sequentially. As the service became even more popular, the FCC stopped issuing official call signs completely, but encouraged users of the service to identify using the call sign form of K followed by the opera­tor's initials and zip code. This can lead to duplication of call signs, but the FCC doesn't seem to be concerned about that.

The Original UHF Service

  Citizens Radio is a family of services, not just the one that rose to great heights of popularity during the 1970s. As originally conceived of and defined by the FCC-long before cellular mobile telephony-hobby-type conversations were explicitly forbidden in the service. Small businesses, many of which provided a service of some type-locksmiths, delivery services, and plumbers, for example-used the Citizens Radio Service to expedite and run their businesses efficiently. No one "owned" or was assigned to a particular channel. All users shared the channels available.

     The FCC established the first Citizens Radio service in 1947. A group of frequencies in the 460- to 470-megahertz range was assigned. This service still exists and is properly called the General Mobile Radio Service (GMRS). A license is required. Recently, the microwave band of 31.0-31.3 gigahertz was also opened for GMRS operation.

     Although UHF frequencies were widely used in military equipment during World War II, the near-microwave nature of the technology involved made production of commercially manufactured equipment expensive. Hobbyists were capable of building the required equipment but faced stiff certification requirements in order to legally use their creations.

     Even so, the new service was appealing to some early pioneers. John M. Mulligan, who was employed as a radio engineer, became the first recorded CB licensee in 1958. Mulligan, who had ties to industry, built his own equipment. By year's end, 40 citizens in the United States held FCC licenses in the new service.

     The same year, a single 3-watt experimental station heralded what would become Class D service, operating in the 27- megahertz range, often referred to by its wavelength of 11 meters. A total of 23 discrete channels were originally assigned to the Class D service. In 1977, to help relieve the congestion that had developed, The FCC increased the number of channels to 40. Several additional attempts to add more channels have not been successful.

     For a few years in the 1950s, the 11-meter band was assigned to the Amateur Radio Service as compensation for other spectrum reassigned from the Amateur Service. Amateurs retained the nearby 10-meter frequency range.

     By the 1960s, hobby magazines were filled with articles on building radio transceivers for the service as well as advertise­ments for kits that could be assembled. Heathkit, EICO, and Allied made many of the kits available. The EICO transceiver lives on today in reruns of television's Andy Griffith Show-it's one of the units seen in the Mayberry courthouse.

Gas Shortage Fuels Popularity

     The 1972 gas shortage in the United States played a major role in making the CB service popular. Originally, truck drivers relied on their CB radios to help each other locate fuel. In a short time, the general public caught on and began to purchase CB radios as well.

     Seven million units were sold in one year during the peak years of the 1970s. Even though CB has returned to relative obscurity in recent years, an estimated 3.5 million units are still sold each year. Today, the service's value as a traveler's aid and means of emergency communication has largely been supplanted by cellular telephones. CB sales in the trucking and freight industry, however, have never slowed.

     Popular culture embraced CB radio, including the jargon developed by truck drivers. Even the FCC has its own "han­dle"-Uncle Charlie. The song "Convoy," written and performed by C.W. McCall, a marketing executive, helped to fuel sales of CB units. A movie by the same name; another titled simply Citizens Band; and the popular movie series Smokey and the Bandit, starring Burt Reynolds, Jackie Gleason, Sally Fields, and Jerry Reed, are further evidence of the impact of CB during the period.

Public Service

     Long before the advent of 911 emergency telephone systems and cellular phones, CB radio provided an effective emergency communication system. There are numerous examples of how CB radio has been used for public service.

     On 23 January 1962, long before CB's rise to popular icon status, Henry B. "Pete" Kreer, a CB enthusiast, recruited the Hallicrafters Company (a manufacturer of radio equipment) to sponsor the REACT program. Kreer got the idea during a Chicago snowstorm after using his CB radio to help a family stuck on an expressway with a very sick child and a disabled car. The REACT concept was simple. Initially, a team consisting of three members agreed to monitor for CB emergencies. Today, there are thousands of teams, with teams in nearly every community, to monitor for emergencies around the clock.

     In 1964, with 800 teams in place, it became apparent that trying to monitor all 23 channels was a difficult if not impossible task. REACT called for the establishment of a voluntary National CB Emergency Channel. Thanks to their efforts, in 1967 the FCC designated channel 9 as the CB emergency channel, restricting communication on the channel to that associated with emergency operations.

     Although 9 is the only channel on which use is legally restricted, other channels have become de facto standards. Throughout California and western states, channel 17 is the unofficial "trucker's" channel. Nationwide, channel 19 is used by truckers and other motorists, especially for speed-trap advisories. Channels from 30 to 40 are used for SSB communication. Although most CB activity uses AM modulation, SSB is authorized with the advantage that all radiated power is concentrated on the information being transmitted, rather than having a large portion consumed by a carrier wave.

     Over the years, some have attempted to make the CB service into an unlicensed version of the Amateur Radio Service by modifying equipment to operate on frequencies not officially assigned, boosting power beyond what is allowed, and erecting antennae at variance with the law. CB operators and amateur radio enthusiasts or "hams" are often indistinguishable in the public mind. Operators in both services assist in natural disasters and provide communication for public events. Although both serve as valuable communication assets, they remain distinct services with different primary purposes.