Amateur Radio Frequencies

Amateur radio communications during emergencies may occur over varying distances. Ham operators use particular bands or frequencies, depending on how far they want their radio signals to go.

• Communications within a local area, such as a neighborhood or a city, use VHF/UHF frequencies. These frequencies are high enough that the radio signals pass through the ionosphere and are not refracted back to earth, and amateur stations must be relatively close to each other and within direct radio contact with each other. Usually, the 2-meter and 440 bands are used for local communications. Typically, communications can occur over a 8-10 mile radius, depending on the power and antennas used and the terrain involved. Repeaters may be used to extend the range of communications and to overcome obstacles that might hinder direct contacts.

• Communications over relatively long distances, such as 30 miles or more may use HF frequencies that are low enough to cause the signals to be refracted by the ionosphere and reflected from the surface of the earth. Depending on the frequencies used and time of day, radio signals might go distances of several thousand miles.

Except for this brief mention of HF frequencies, the information in this site pertains to the VHF/UHF frequencies.