As of 2015, it is illegal to install a linear amplifier or any other type of power amplifier to a Citizens Band (CB) radio in the United States, notes the Federal Communications Commission at FCC.gov. A CB radio is a two-way system of voice commission that operates on 40 channels between 26.965 and 27.405 MHz.
While installing a power amplifier to a CB radio is illegal, the general public can use a CB radio in the U.S. at any location that is regulated by the FCC. The FCC requires certification of any CB transmitter used in the CB Radio Service. CB radios can be used for business and personal communications.
The FCC also provides several other tips for those interested in installing and using a CB radio transmitter. The power output of a CB transmitter cannot be raised. There are no height restrictions on CB radio antennas, whether they are for hand-held radios or mounted on vehicles. For other antennas, the maximum height is 60 feet from the ground or 20 feet above the highest point of the structure in which it is mounted. While channel nine is reserved for emergency communications, they can occur on any channel and must be given priority. CB radio users can choose their own handle.