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Old 10-21-2017, 09:18 PM
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bgadow bgadow is offline
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Join Date: Oct 2003
Location: Federalsburg, MD
Posts: 5,397
CTC-5 Lost Vertical Deflection

Calling the CTC-5 Guru's!

Well, first, it's been way too long since I logged into VK. Nothing personal! Just been working on other things. About time I (tried) to fix something.

I hadn't fired up my Whitby in almost a year. The last time I ran it the convergence looked terrible & since I finally cleaned the stack of other sets off the top of it, I could pull it away from the wall. It powered up without drama (which has not always been the case with this set) and it ran for about 30 seconds before the vertical collapsed. Now, I really am not in a hurry to pull the chassis so I'm trying the easy stuff first. Here's where we are so far:

-I recapped the set years ago.
-I tried subbing both the 6AQ5 & 6CG7 in the vertical circuit, as well as wiggling them around & watching for any changes.
-There is a 50mfd cap from the vert output xsfmr to ground; I clipped in another (the grille underneath is missing & I have limited access), no change.
-I tried the old trick of running a .047 cap from the grid of the 6AQ5 to filament to introduce a pulse of sorts & that gave me about 3/4" of deflection.
-I jumpered resistors across R122 & R126 with no changes.
-I've tried tweaking vert hold, height & vertical centering, no effect. EDIT: I just pulled the front control panel off so I could try the vertical lineage control. I found that if I turn it rapidly I get a some deflection, but only as I'm turning it. Is that a good clue?

I'm going to try to grab some voltages & do some further poking & prodding. I really enjoy tinkering on sets like this & some may think I even know what I'm doing-but I'm not the greatest diagnostician. As always, advice is welcome!
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Bryan

Last edited by bgadow; 10-21-2017 at 10:12 PM. Reason: Additional information
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