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Old 07-07-2011, 12:20 PM
DaveWM DaveWM is offline
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still fighting that darn tendancy towards line pairing...
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Old 07-09-2011, 08:35 PM
DaveWM DaveWM is offline
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fooled with it some more, tried some new vert tubes (6GF7), no change. every now and then I can get it to not pair up, but most of the time it does (messing with the vert hold, but its not a very reliable way to get it).

I couple of things noticed. I need to very nearly max out the lin adj (on this set its the one that feeds the plate from the boost, I know on some sets its called the vert height, I dont know why they cant make up their minds on this) to get the linearity as good as I can get it. Also I noticed its a tad jumpy, you can really notice it when there is some text near the top of the screen. I dont know if this "jumpy" vert is tied into the "jumpy" line pairing but it seems like it could be.

While I did test the various caps in the circuit with my old school cap tester the 2kv .0086 cap from the plate of the output side of the multivibrator could not be tested at rated voltage (tester only goes to 450v). there is also some little 680pf disc caps that I am not sure of the function.

I never did scope the grid output from the integrater the way the sams said to (bright down, tube out) to look for excessive horz hash.

I think I mentioned before the last tough dog line pairing issue I had was on a B&W maggie, it was from the yoke, some how it was getting horz back thru vert out transformer and back into the vert osc. I only found it by comparing a working set to the bad set and seeing all the hash on the bad set secondary.

I have another CTC-16 (this is a clone) so I could do the same, or just try a different yoke (I have an NOS). Its really a pita as the rest of the pic looks fine.

I dont know if the boost voltage could be causing this (if it had hash on it from a bad cap). I think I checked it, but not sure. again I could prob scope the it and see, again not being experienced in this I would need to look at a working set to see what it should look like...
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