Contrast

[DaveWM]

I would guess so, but to trouble shoot, I would still recommend the composite video at the grid fo the video amp tube. Just make sure there is no voltage before hooking up to the dvd. I couple thru a big cap (.1 should do) to avoid any DC just in case there is any.

[DaveWM]

I have had some pretty bad testing CRTs (b&w) that still make an ok pic, not great but ok. by passing the tuner/IF allows you to quickly know where you are, plus is a good way to see how good your tuner/IF is. I compare the picture (RF at tuner to composite at grid) to determine how well the alignment is setup.