Since my parents still have the Sylvania, I should go over there one Saturday night and watch it there, and completely throw myself back in time! I absolutely can't believe the TV still works!
There was a brief interval after the U.S. converted to digital television when I hadn't yet bought a modern TV set. I used a converter box to watch digital broadcasts on my old TV.
It was weird. The picture seemed small. The image was square within the curved edges of the CRT. So I don't think you'll get that old-time feeling from a digital broadcast. The thing to do is watch a Star Trek
DVD on you parents' old TV. That would look about right.