Quote:
Originally Posted by old_coot88
Back in the day, 210ma. when 'on dip' was considered nominal.
200 would have been all the better.
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Finally had some time to sort things out a bit better and made some improvement. First, the set is holding a steady 210mA, or did for at least an hour. The corona arc is all but gone, but you can sometimes hear it hiss just a bit, but not showing up on the screen. I'm real happy with that, but I would like to have it completely clear of any corona discharge. Possibly some more extended play time will work that out.
Either earlier here and/or on another related thread I mentioned complete loss of color. I have read that 6GH8 tubes were troublesome for whatever reason. That must have been an understatement as I remember checking the single tube in my set's compliment (which acts as the chroma reference oscillator) a while back and it checked OK, but I can't remember if that test was done on my cheaper Accurate Instruments tester or on my Hickok 6000A.
Either way it goes, I pulled the tube tonight and plugged it into my Hickok and the tube was really weak (in the red) on both the triode and the pentode tests. Luckily I had about 8 of them in my used collection and of them all only one came up to the question mark symbol between the bad and good scale on both tests. I thought that it was a bit odd that most of the tubes I had were testing in a very similar range which fell within that ever present "diodes OK" area, I tossed any that were below that point until perhaps I just try them in the set.
The one that was dead in the middle (question mark) got put in the set and BAM color at long last!
That's been a long time coming as it's was the first thing to go wrong with the set. Now if I can get that ugly white line (Barkhausen?) out of the left side of the picture and do some convergence work I might be one of those lucky guys who have Zenith color sets that they don't have to post about because they work as is! LOL!
I'll have to find me a CTC something to keep me busy if this goes right. I really don't have time anymore for a proper recap if repair is all that is needed. We will see.....