very very strange - question involving B&T modulator

[Adam]

I'm only a few blocks from the stadium, so that makes sense. If it's combining with my ch2, to show up on ch3, then wouldn't it be around 120MHz?

Even though the game is long over, and there's no more audio signal on ch3 like before, I'm still getting that weird video signal on ch4, that must be caused by something else.