CB radio service began in United States during the 1940's as short radio communications for business and personal use. Their popularity grew in the 1960's, with small traders and service people using them. In the '70s, technological advancements promoted the usage of CB radio services. CB slang terms and codes gradually evolved, with truckers using their own codes to send alerts to their counterparts.
FCC Rules And Regulations
The Federal Communication Commission (FCC) regulates CB radio service. Initially, CB radio services were in the UHF band between 460 to 470 MHz. Two classes of CB radios?Class A and Class B'were popular. Class B types were simpler, but limited to smaller frequency ranges. The FCC restricts the frequency allocation.
Any individual can operate a CB in the United States. However, foreign nationals are not eligible to operate them. There are 40 authorized CB channels, and anyone can utilize any of these channels (except channel 9, which is meant for emergency call transmission). The channels are operated on a shared basis; there are no territorial limits for CB radio operations within or outside of the United States, except those restricted territorial limits.
The FCC requires an individual to use certified equipment; further modifications aren't allowed. The output power is restricted to four watts for an AM transmitter, while up to 12 watts of output power is allowed on a single sideband transmitter (SSB). The antennas should not go beyond 20 feet from the point of mounting and not beyond 60 feet from the ground level.
The FCC takes strict action against people who violate their rules and regulations, and also those who use modified equipment. Severe actions are taken against illegal users operating in the range of 26MHz and 30MHz. Even retailers are o't spared if caught selling non-type approved equipment.
GMRS Bands
Additional radio frequency bands have been given permission to operate. Located in the band of 460 to 470 MHz, it is called General Mobile Radio Service, or the GMRS, and requires a license. In addition to this, the FCC has opened a microwave band of frequency at 31 GHz, which also requires a valid license.
Restricted Channels
All 40 channels can be used; however, some channels are devoted for special purposes. As already mentioned, channel 9 is meant for emergency calling services. Channel 17 is the unofficial trucker channel; truckers communicate traffic problems and other emergency needs on channel 19. Channels 30 to 40 are allocated for single sideband services.