what do the w and k stand for in call letters
Call signs in North America Many countries have specific conventions for classifying call signs by transmitter characteristics and location. The call sign format for radio and television call signs follows a number of conventions. All call signs begin with a prefix assigned by the International Telecommunications Union. For example, the United States has been assigned the following prefixes: "AAA"â€“"ALZ", "K", "N", "W". For a complete list, see international call sign allocations.