I don't recall our PBS stations marathoning through cliffhangers, but that would have been cool. (Back then, during the antenna era, PBS stations didn't always tune in so well in our area, but I'd strain my eyes through a lot of static to see THE PRISONER or UFO.) In the Eighties, I recall catching serial chapters on PBS when they ran MATINEE AT THE BIJOU. After STAR WARS blew box offices away and George Lucas mentioned being inspired by the Flash Gordon serials, one local station in late 1977 (or early '78) decided to take advantage of the interest. After the 11:00 news on Saturday night they would run an episode of THE OUTER LIMITS, followed by a chapter from FLASH GORDON CONQUERS THE UNIVERSE. Not a bad way for a kid to spend an evening, back then. (Especially if you didn't have a car, yet.)