[zenithfan1]

Just wiggling it may not indicate a bad tube, sounds like a bad socket connection. Try spraying a very small amount of de-oxit in the socket and replace the tube, wiggle it again and if it stopped, try tapping on the tube with your fingernail or a popsicle stick. If the problem continues, the tube might be shorted. If it goes away altogether, it was just a bad connection. I had a problem like this with the '63 Zenith I recently restored, drove me nuts for a few days. It was bad socket connections at several I.F tubes and the sound detector IIRC. Good luck with it, she's a nice set. I have a similar chassis in my Admiral.