Frequencies
High frequency (HF) 3-30MHz
These frequencies have the longest range and are used mainly for the military, government, maritime sea-to-shore/ship-to-ship, and aviation air-to-ground communications. They are also popular with amateur radio operators.
Very high frequency (VHF) 30-300MHz
Common uses in this band are for DAB (Digital Audio Broadcasting) and FM radio, and air traffic control, as well as communications within the emergency services prior to the introduction of TETRA. Your local emergency department should have a VHF radio base station to communicate with the regional Emergency Operations Centre in case of other communications failure.
Ultra high frequency (UHF) 300MHz-3GHz
UHF has a short range, and waves travel mainly by line of sight. These frequencies are used for television broadcasting, mobile phones, GPS, and personal radios when used in close proximity (for example at the scene of an incident). The lower end (380-400MHz) contains the ranges used by TETRA.