all righty ill try keep this simple......most modern cb radios have the capability to transmit on the varying frequencies allocated by the region they are sold in. some countrys have strict limits on the freq and the power output. however most countrys including ireland dont police the cb bands unless sombody starts interfering in something important.
the advantage of the modern cb is that when you change from one region to another ie, ireland to the uk you can switch the radio over to suit the region your in.
for a cb used in ireland your looking to get a radio that transmits on the 40 channels between 26.965 mhz and 27.405 mhz.preferably with am and fm.
to be honest as far as modern cbs go, one is just as good as the next, i would suggest to stick to the well known brands like president, cobra, tti, but do not buy a radio that has 27/81 stamped on it as this is restricted to the uk band only.
the cb is was probably the first social networking device ever but these days its use is usually restricted to events and specific communications.
as for the marshels at rallys they are probably using two way radios, well if they have any sense they will be. if they were to use cb's they are open to interferance and shitehawking from spectators and locals who have access to cbs. if they have to talk over a couple of miles there probably on high band vhf or on uhf. there are websites that could probably tell you the exact freq but you would need a scanner to receive them. once you go outside the realms of the cb bands the airwaves become policed much more stringently so they would have to be licenced so somebody somewhere has the list of radios and the freqs there on.
if they are using pmr 446 radios which are licence free they would only have very short range and you would have to be on top of them to receive them, also pmr 446 is an awkward band to receive on a scanner because of the channel spacing and is also open to interferance from idiots with similar radios.
