>I have a BC18Z I have for connecting the VAXstation to the monitor, keyboard >and mouse. With this cable, a red hue across the whole screen flashes on and >off about once a second, the other colours are fine and the screen is >legible. There is also a thin dark line that scrolls up the screen >continuously. This happens on two different monitors. I don't think it is >the VAXstation itself either, because swapping with another cable the >problem goes away.

Me too! I have a VAXstation monitor cable that does that too or something very like it. It's been a while since I looked at the problem and I don't know where the cable is now. I think I did a DC comparison between the bad cable and a working cable and failed to find any difference. Unfortunately, the only solution I could come up with was the same one you did, use a different cable :-(