I'll start. Feel free to chime in.
There was a station that broadcasts out of Scranton -- probably still does -- called 590-WARM. Growing up, it was my only link to Major League Baseball. The Poconos are a vast place, far less populus than they are today, and we lived about six miles in either direction from the closest cable line. That meant either a cable bill of several hundred dollars, or a roof-top antennae and fuzzy picture. My parents chose the fuzzy picture.
That left radio as the chief option for all things baseball. The Phillies, apart from their run in 1993, weren't very good. Better yet, they stunk. Yet there was still something special about flipping on the radio in the bedroom or on the dashboard of the family mini-van and hearing Kalas' deep voice crackle over the AM airwaves.
There are a lot of people in Philadelphia who knew Harry the man better than I. But I think I speak for most of the metro-area in saying that we all had wonderful relationship with that voice.