CRT Distortion lines on inputs, perhaps caused by temperature?

[aseriouslee]

I have tried listening to radio and looking for patterns in speech, but the pattern moves so quickly it's only comparable to static. I wish I could show this on video but I can't get a good recording.

[StillTrying]

I've looked at the JVC-HV32D40BK manual twice, but I'm running out of ideas.
Maybe something in the TV itself that only effects that input.
Maybe they're there all the time, but you only see them when the 2 frequencies drift so that a multiple of them matches.