VT320's,

The most recent DEC termainl I have is a VT240. I don't own a VT220, let alone a VT3xx. People here migth well be interested in them... It's time for me to admit the tiem I was a total idiot. I was using a VT101 (IIRC, maybe a VT100) for real work, and the screen was dim. So one morning I took the coveroff and checked the CRT voltages. All looked fine. I check ted the video amplifier circuit, that was fine too. All signales were what I expected. I was about to try tp source a repalcement CRT when I did what I should have done in the first place. I cleaned the screen. after remocing a thickj layer of dirt, the picutre was nice and bright ... I asusme you';ve tried cleaning the screen in yours. In genral a dim image is due to too low a beam current. Either because one of the CRT votlages is off (too -ve a control grid, not high enough +ve voltage on one of the anodes) or because the CRT cathode is losing emission. In general a careful tweak of the sub-brightness preset (if there is one) and the first anode ('a1' or 'g2' depending on which side of the Pond you are on) presets will do no harm and may improve matters. If the CRT is filing, this might get a bit more useful life out of it. -tony