DAVE SCOTT 3:00 to 6:30 P.M. At 5:30 one evening the housewife in Mt. Lebanon wondered whether to put dinner on the table or back in the overn to keep 'til Dad got home. He was late. The the voice on KQV said, "Don't worry, Mom - the Old Boy'll be a little late tonight. It's raining downtown and the traffic cops are all in the cigar stores." That's the "Great Scott" - Dave Scott - a fast man with a record, a road report., and a quip. Pittsburgh thinks so, too, as shown by Dave's tremedous rating in both Hooper and Pulse. Scott is blessed with an empathetic, gravelly voice that gets to the heart of the gigantic Pittsburgh steel-working force. In his early 40's, Scott is the very embodiment of the mature, hurry-home commuter racing from the office and the plant over Pittsburgh's twenty-some bridges and three tunnels. Dave's also quite popular with the younger set. His activities with young people keep him in constant demand as a speaker and entertainer at district events, and that younger set listens to Dave with the blessing of the parents. After all, he has been talking to Pittsburgh for over 20 years. Dave and his audience have matured together.