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Originally Posted by JCFitz
Can I ask you one more question on this chassis since you have the Beitman's? What voltages and pp are shown on the HO tube grid and screen grid ?
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Beitman's says -30V on G1 of the 6CU6 horiz output tube, and it shows a triangle wave of 145V (I presume that's peak to peak, it doesn't say).
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I replaced a bad drive trimmer that maxed out at 400 pf (half the stated max value). The new one goes up to over 800pf and it too is maxed out to stop the plate from glowing.Couldn't eliminate it with the other trimmer. Trying to figure out what is amiss that causes me to have to max out the trimmer to just barely get enough drive (if I have enough) instead of getting a drive line like I would expect with a trimmer maxed out.
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The Beitman's diagram has in series a 0.0047uF cap with that trimmer. A note says "may be used in some models". If your set has it, maybe it's bad?
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Sams says -28 on the grid and 80vpp which I get when I got the line voltage set to give me the rated 265v B+ but Sams quotes 145 v for the screen grid. I'm getting more like 185-190v.The screen grid resistors are new. The originals were burnt to a crisp and the 8200 measured way low.
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Beitman's has 145V for the screen grid. It says B+ is 270V, so yours is close enough I'd think. Boosted B+ is 520V, terminal 8 of the flyback transformer (don't know it that is marked, though).