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After months of on-and-off work I've decided the Whitby is good enough for now. Here is what I did since my last update:
I replaced all the low value (mica, etc) caps on the horiz. osc. board along with some resistors that were just a little off. I was eventually able to get the oscillator waveform to look like the picture. While I was at it I did the contrast control mod; funny, in another thread old tv nut mentioned doing the mod according to the magazine article and he ended up with the travel being backwards. Well, I purposely wired it the opposite of the article-and I ended up backwards, too! Not sure how or where it got messed up both times, but not a big deal.
I was able to gain a lot of stability; my lingering problem was high voltage that was too low. The best I could get with brightness turned down was 18.5kv. I looked at the waveform going in to the HO tube and found the peak was very rounded, not sharp as pictured in Sams. After the above recap this was also corrected but the HV did not improve. I spent a lot of time measuring currents and voltages at the HO and regulator and the only thing that was out of spec was the drive voltage to the HO. It should be 190v but instead was running 175+. The resistors in that circuit test good and the caps are new. I finally decided not to fight it anymore as the set performs pretty well as-is. I went ahead and did the setup-I was surprised that the purity looked fine. Yeah, I know, in the first photo posted below there is some impurity in the corner-only shows up on the red. That is one of a few problems I'll save for some other day. (likely some other year!) There is some color smearing, for one. I guess that term is correct. Delay line? Or just something off kilter on the color board? And vertical lines have a waviness-not a crawl, they stay put. I'm not going to let this bother me as this is about as good as this set has been since I bought it, and I consider it an ongoing project. With time my abilities, hopefully, will improve, and I'll feel more confident when it comes to tackling these other problems. For now I'll just kick back and enjoy the show.
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Bryan
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