I had several televisions where the reception was off a bit, but if you turned the dial a very small amount, like 1mm or so, it would look better. So we would

I had several televisions where the reception was off a bit, but if you turned the dial a very small amount, like 1mm or so, it would look better. So we would wedge matchbooks or cardboard in the dial to hold it there. Happened across several different models. Also ones where the flyback transformer was dying, which would collapse the picture. But banging the TV would bring it back to life for 10-30 minutes. So we had a pile of shoes near the couch to throw at the TV as needed.