On “MAS*H”, most of the PA announcements were made by a voice that was not any on-screen character’s. Announcements were even made while the scene was in Radar’s/Klinger’s office, where one would assume the PA equipment was.
With a little digging, I found that it was actor Sal Viscuso, who was better known as Father Tim on “Soap”.
Question is: why would an actor do voice work for 11 years of a show (and the movie) and not get some credit for it. Sometimes the PA jokes were funnier than Hawkeye’s.