[Radioroslyn]

Or when you "cleaned" the coil did it remove the insulating coat of lacquer from the winding under the feedback winding?  Did you see bare copper?

[whirligig]

The impedance of 38 gauge will not do that. It is low no matter what.

Could it be you wound it in opposite direction? Have you tried swapping the ends?

I recalled some spots of green oxidation. Well, that's the same as bare copper. I better have the boss order some of that gauge of wire then.

[whirligig]

Yes, I reversed the wire and it made no difference.

[morzh]

Oxidation is no good either. Is the continuity still there? At any event, if you see oxidation, it has to come out and be replaced.

And the bobbin has to be baked. And if there is still celluloid film left, has to come out too - this is what causes oxidation.

[whirligig]

All the celluloid was removed and the windings underneath were treated with a solution of ammonia and water after I scrubbed off the corrosion. Could be the winding underneath was compromised and shorted.

[Steve Davis]

Ammonia on copper, always a bad idea.

Steve

[morzh]

If you see corrosion, remove the winding and redo.

[whirligig]

Wow, it's been nearly a year since I posted this and I didn't give a conclusion. I apologize. Thanks to morhz and Steve I revisited this coil late last year and removed the secondary and corroded primary and rewound them. I installed this coil in another 60 that I cannabalized earlier and it now works. The second time around went much quicker. Thanks.