|
after fighting poor greens I decided to try the vectorscope again. this time I clipped on the other side of the grid coupling caps for RGB on the CRT. Much better, did not effect the CRT display at all.
While there were color bars, the blue and reds were fine but the magenta was weak as was the green.
looking at the scope you could see the fingers but they were much more of an elipse that an a circle.
My interpretation of this is the phase of the CW from the osc was not correct to one of the demodulators, and the transformer that changes the phase needed to be adjusted. Since green is derived from the X and Y demodulators, then a defect there would really mess up green.
What I like about the vectorscope is the instant visual response (not just that its changing but that its changing in the right direction.
as it turned out about 1/4 turn of that phase adj transformer was able to open up the elipse and give a nice circle pattern, when I looked up at the CRT it now had a very nice color pattern.
This is the second time the vectorscope came to the rescue for me, I highly recommend one. Besides they also have nice dot and cross hatch settings.
funny thing is how good you can get flesh tones even with green so useless, I guess its just the flesh tone does not need much green unless your looking as Spock.
|