Recoating flyback in RCA CTC-11
 

Here's what I see when peeking into the h-v cage of my RCA CTC-11.

I guess this means recoating is in order. I have a little bottle of GC corona dope which I bought a while ago but haven't used yet. Would that work?

And if so, would I recoat the naked-looking structure to the right of the doughnut, as well as the other side? And, I guess you would carefully use a heat gun to get the old wax blobs out of there.

Sorry to be so dense, but I haven't done this before.

Phil Nelson

Hi Phil,

I would leave it as it is if the set works. Check the line output transformer for high currents and try to lower the cathode current of the line output tube to the lowest possible value. If you seal the transformer, there is no possibility for water which comes with the air into the coils, to dry out.

- Eckhard

Recoating
 

Phil,

Is your CTC-11 arcing or sizziling or giving off blue corona? If not, I would leave it alone. Carefully remove any wax dribbles, but don't break any wires doing so. A little heat from a heat gun (or soldering iron) will soften the misplaced wax and allow it to be removed. When in doubt, leave it alone. The HV winding (where most of the troubles arise) is potted in that (silicone rubber?) substance, which usually holds up well. I am not much of a fan of chrona dope. If there is a chrona problem, it is best to address the underlying problem, rather than just paste ove the root cause with dope.

Of course, opinions may vary....

The set looked decent the first time I powered it up. I didn't hear any sizzling or Bzzt noises from the back, but wasn't peeking inside the h-v cage at that time.

I think I'll quit worrying about this for the time being and finish replacing the electrolytics.

Thanks!

Phil Nelson

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