Westinghouse K840CK15 Restoration

[dtvmcdonald]

You can do a lot better than that on a 15GP22. The key is to not force it to be too bright. Be sure that you are never driving the red gun into grid current.

I did on my CT-100 when I first got it. The Westinghouse at the ETF has on occasion done much better. I need to look at what adjustments the Westinghouse has. To do it on my CT-100 I had to add one additional adjustment pot temporarily to get it
right, the put in the correct matrix fixed resistor.

I looked: the Westy has sufficient controls. But do note that the color matrix
controls all interact, as the matrix resistors do not drive current into a virtual
ground, as they would the the mixer tube were an inverting op-amp. The CT-100
does have feedback there so the interaction is less. Tweek until its right.

The final criterion is looking at the screen through good color filters and/or looking at the dots on the screen through a magnifying glass to see that the "off" dots are off.
Note that DC restoration is never perfect on these tube sets like it is on modern
solid state ones.

Finally ... be sure that AGC is set right so that there is no clipping of the composite video.