Citizens band radio (CB radio) is a land mobile radio system, a system allowing short-distance one-to-many bidirectional voice communication among individuals, using two-way radios operating near 27 MHz (or the 11-m wavelength) in the high frequency or shortwave band.

2023年4月30日 · is there a future for AM SSB Citizen Band radio in 2023? or will the 27MHz band be eventually re-allocated? I hear little to no activity in this part of Australia.

2024年9月30日 · The United States Government has exclusive usage rights to the 25.33 MHz-25.55 MHz band, the 26.48 MHz-26.95 MHz band, the 27.54 MHz-28.0 MHz band, the 29.89 MHz-29.91 MHz band and the 30.0 MHz-30.56 MHz band.

The 27 MHz CB27/81 Bandplan is a list of the channel frequencies for FM CB radio in the United Kingdom. Unlike CB usage in the United States, and subsequently elsewhere in the world, the original UK 40 channels progress in order with 10 kHz spacing.

Everyone has heard about the CB radio popularized in the 1970s by the romaticized trucking industry and movies like "Smokey and the Bandit." The original Citizen Band frequency allocation from the FCC is in the 27MHz band.

2025年1月19日 · The 10 km range, 27 MHz transmitter circuit explained here uses citizen's band which consists of 2 main types of users: radio control (R/C) modellists and users of low-power FM transceivers for local communication. However, here it is designed and intended for testing antennas and aligning receivers.

The 11 metre band now appears, unofficially, to cover anything from 25 to 28MHz. Warning: It is illegal to use frequencies and modes not specified for use in your country by licensing authorities. Here is a very useful document from Ofcom concerning CB spectrum use, information and operation in the UK.

At first inspection, 27MHz seems like an odd, archaic band. With a wavelength of around eleven meters (!), the antennas would seem to be prohibitively large, while the allocated spectrum is, by the standards of modern “digital” communication, a tiny handful of 10KHz wide channels.

2020年1月29日 · In the U.S., 27MHz (with up to 6 color-coded channels) is commonly used in both hobby-grade and toy-grade RC vehicles. Those frequencies are: 26.995 MHz -- Channel 1 (Brown)

The ISM bands are also widely used for radio-frequency identification (RFID) applications with the most commonly used band being the 13.56 MHz band used by systems compliant with ISO/IEC 14443 including those used by biometric passports and contactless smart cards.