Learn how radio stations have call letters assigned.
These beginning call letters are assigned on a geographical basis. For the majority of radio stations located east of the Mississippi River, their call letters begin with the letter W; if the stations are west of the Mississippi, their first call letter is the letter K. However there are exceptions to this rule. Stations founded before this rule went into effect kept their old letters. So, for example, KDKA in Pittsburgh has retained the first letter K; likewise some western pioneer stations have retained the letter W. Since many AM licensees also operate FM and TV stations, a common practice is to use the AM call letters followed by -FM or -TV.