Why is it that American radio stations names always seem to start with the letter K? | Notes and Que

Why is it that American radio stations names always seem to start with the letter K?

Jack Hurley, Leeds, England

• Only those stations west of the Mississippi river start with 'K'. The eastern stations generally begin with 'W'. But I still don't know why.

  Brian, San Diego, USA

• The 'names' were/are originally call-signs, allocated by the US government. They start with K on one side of the Mississippi and W on the other. A fairly well-known piece of trivia.

  Dave, Portsmouth, UK