(a) General rule.--No person engaged on, connected with, or employed by any newspaper of general circulation or any press association or any radio or television station, or any magazine of general circulation, for the purpose of gathering, procuring, compiling, editing or publishing news, shall be required to disclose the source of any information procured or obtained by such person, in any legal proceeding, trial or investigation before any government unit.
(b) Exception.--The provisions of subsection (a) insofar as they relate to radio or television stations shall not apply unless the radio or television station maintains and keeps open for inspection, for a period of at least one year from the date of the actual broadcast or telecast, an exact recording, transcription, kinescopic film or certified written transcript of the actual broadcast or telecast.