Just like each radio or TV station is identified by a unique “call sign” identifier like WABC, likewise each ham radio operator has a unique call sign. Your call sign is automatically generated from the Sequential Amateur Station Call Sign System after you successfully pass your test. However you can request a custom “vanity” call sign at no additional cost.
Call signs (and all of ham radio operations) are governed globally by the ITU (International Telecommunications Union), with each of the 340 participating countries having their own governing body. In the U.S., the governing body is the FCC.
Each call sign consists of three elements.
- A prefix of 1, 2, of 3 alphabet letters assigned by country. In the U.S., the prefix is 1 to 2 letters. For the first letter, the alphabet letters assigned to the U.S. by the ITU are W, K, N, or A. If there’s a second letter, it can be anything.
- A middle numeral. In the U.S., this number corresponds to one of 10 geographic areas in which the operator’s original license was issued. For Colorado, this number is 0.
- A suffix of one, two, or three alphabet letters (A-Z, AA-ZZ, AAA-ZZZ). Note that some letter combinations are not used, such as common “Q-signals” (example: QST), distress symbols (like SOS), and certain other combinations.
An example of a U.S. call sign is W0FP where “W” is the prefix, “0” is the numeral, and “FP” is the suffix. The variety of combinations have led to an abbreviated way to refer to call sign formats, like “1-x-1” (1 prefix, a numeral, 1 suffix), “2-x-1” (2 prefix letters, a numeral, and 1 suffix letter). “W0FP” is a “1-x-2” format.
To avoid misunderstanding in transmission, hams are encouraged to use phonetic alphabet keys in their transmitted call signs. For example, C, D, and E have a similar sound and could be misinterpreted. But Charlie, Echo, or Delta are more clear. There are various standard phonetic alphabets you can use, e.g., the ITU Phonetic Alphabet list. Just be sure that what you use is clearly understandable.
There are several special call signs, including:
- A “Special Event call sign” consisting of 1 prefix letter, a number, and 1 suffix letter. This is a temporary call sign issued to commemorate a special event, like an anniversary.
- A “Tactical call sign” to designate a specific entity during a public service event, e.g., “Race HQ” during a bicycle race.
- A “club call sign” in which a minimum of 4 operators, led by a “trustee,” band together under 1 call sign.