Maybe already mentioned; but in EU CB and UHF are licened if you use high power (+4W) for everything up to 4W (send and receive) you do not need a licence. Everything more you do.The Overland Bound community has settled on some common "calling" frequencies for the most common radio types. These are meant to be a starting point for making contact with a Overland Bound members. If your local region already has other generally accepted practices, you may want stick with them instead.
U.K. 27Mhz CB
License: There is no license requirement for 27Mhz CB use in the U.K.
Squelch: Almost all CB radios will have a squelch control, this additional knob is used to adjust the noise cut-off on the incoming signal. If you find that other people in your group can hear you, but you can't hear them, adjust the squelch down as you may be filtering too much of the incoming signal.
Range: CB power output is limited to 4 watts, so in a typical trail situation, the range is realistically about 4-7km.
E.U. UHF CB / PMR
License: There is no license requirement for UHF CB use in the E.U.
For CB we use generalt channel 16 (4x4)