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Radio call sign

A radio call sign or callsign is a unique designation for amateur, broadcast, and sometimes military radio use. Such call signs are formal, semi-permanent, and issued by a nation's telecommunication agency.

Each country has a set of alphabetic or numeric International Telecommunication Union-designated prefixes with which their call signs must begin. For example:

Table of contents
1 Amateur radio
2 Broadcast call signs
3 Military call signs
4 See Also

Amateur radio

Amateur radio call signs normally consist of a one or two character prefix, a number (which sometimes corresponds to a geographic area within the country) and a 1, 2, or 3 character suffix. The number following the prefix is normally a single number (0 to 9). Some prefixes, such as Djibouti's (J2), consist of a letter followed by a number. Hence, in the hypothetical Djibouti callsign, J29DBA, the prefix is "J2", the number is "9", and the suffix is "DBA". In the Italian callsign, IK1TZO, "IK" is the prefix, the number component is "1" and corresponds to the Piemonte region, and TZO is the suffix. Another example is WB3EBO. "WB" is the prefix, the number "3" most often indicates that the station is located in Delaware, Maryland, Pennsylvania, or the District of Columbia. The suffix is "EBO".

Broadcast call signs


Broadcast stations in the U.S. and Canada are assigned three or four letter callsigns. Many of these, such as Baltimore television station WJZ, Denver Radio Station KOA, and Pittsburgh Radio Station KDKA, have long historical associations. Others are changed frequently as the station changes format. Many stations prefer not to use call signs at all, since a slogan is more easily remembered by listeners filling in diaries for the Arbitron Company's radio ratings. However, in the U.S., the Federal Communications Commission does require periodic identification using the formal callsign, as close to the top of each hour as possible.

There are some common conventions followed for call signs in North America.

The Rosicrucian Order, AMORC of San Jose, California used the callsign 6KZ.


In Australia, broadcast callsigns begin with a single-digit number indicating the state or territory, followed by two letters for AM stations and three for FM, also, some AM stations retain their old callsigns when moving to FM, or just add an extra letter to the end. Australian broadcast stations used the prefix VL-, but since Australia has no nearby neighbors, this practice was discarded in use.


In Europe and much of Asia, callsigns are normally not used for broadcast stations.
Japan, South Korea and Taiwan are exceptions to this general rule. Other countries have yet other formats for assigning callsigns to domestic services.

Military call signs

US Army

United States Army uses fixed call signs for Army stations which begin with "W", such as WAR, used by U.S. Army Headquarters.

US Air Force

United States Air Force uses semi-fixed identifiers consisting of a name followed by a two or three digit number. The name is assigned to a unit on a semi-permanent basis; they change only when the U.S. Department of Defense goes to DEFCON 3. For example, "JAMBO 51" would be assigned to a particular B-52 aircrew of the 5th Bomb Wing, while "NODAK 1" would be an F-16 fighter with the North Dakota Air National Guard. The most recognizable callsign of this type is Air Force One, used when any plane is carrying the U.S. President, or Marine One, used to identify any helicopter doing the same thing.

Fixed call signs for USAF stations begin with "A", such as AIR, used by USAF Headquarters.

US Navy/Coast Guard

The United States Navy and United States Coast Guard use a mixture of tactical call signs and formal call signs beginning with the letter N. For example, the carrier USS John F. Kennedy has the callsign NJFK.

See Also