Those five channels were NBC, ABC, CBS, PBS, and the local UHF channel. The last of these was usually my favorite as a child, especially when it ran a 3-day Star Trek marathon when I was 8 years old. I never felt deprived, even when I had to tweak the aluminum foil around the TV antenna to improve the reception.
Local listings included another PBS station in Allentown, that some of the outlying suburbs might have been able to get reliably. I don't believe I ever tried, since their programming didn't vary all that much from the other one. In the later '70s I believe a couple more UHF stations popped up, and as cable was just getting established in the early '80s, as Philadelphia proper dragged its feet in granting cable franchises, there were even one or two broadcast "scrambler" stations on UHF channels, were you could rent a decoder box to pick up their movie offerings. Those died out quickly once cable was widely available.