smear

[DaveWM]

do you have a dvd player or converter box? all you need is an RCA cable connect the outer shield part to the chassis and the inner to the grid. use the video out. the audio will not work of course but you will be able the check the video

Before you make this connection check the chassis to grid with a voltmeter.

I goofed once and thought I was a the grid (which was near 0v) but was in fact at a B+ take off (the video test point was next to a B+ test point, it was late and I was tired). You dont want to fry your DVD or video source.

to be safe you could isolate with a large value cap like a 1uf or larger. Too small and you will get....smear

but you dont really need it, just check that voltage before hooking up. I do this all the time to see how well my IF alignment went. If its as good as the composite signal then I know it cant get any better.