All of the following requirements must be met in order that an employee may be exempt under section 13(b) (9):

(a) The employee must be “employed as” an announcer, or a news editor, or a chief engineer.

(b) The employee must be employed “by” a radio or television station.

(c) The major studio of such radio or television station must be located in a city or town which meets the prescribed population and locality tests.