Restoration begins on Ed Reitan's CTC-7

[ohohyodafarted]

It is my opinion that copper wire corrosion in the HV cage is not uncommon. I had this problem on my Hallicrafter 820 set. I think this is exacerbated inside the HV cage due to corona that can cause ozone, which is highly corrosive. A small knick in the varnish covering the wire can expose bare copper which will oxidize over time and physically weaken the wire.

[etype2]

Originally Posted by ohohyodafarted

It is my opinion that copper wire corrosion in the HV cage is not uncommon. I had this problem on my Hallicrafter 820 set. I think this is exacerbated inside the HV cage due to corona that can cause ozone, which is highly corrosive. A small knick in the varnish covering the wire can expose bare copper which will oxidize over time and physically weaken the wire.

Thanks. The insulation broke away with very little effort exposing this broken wire coming out of the windings.

After repair.

[Josef]

Nice, but I would j hook the copper wire to make the connection long term stable. In your case it could be better not to touch the connection any more to avoid further damage. I usually clean flybacks (from our european b&w sets) with WD40 to protect them from moisture and soften dried out isolations. Take care if there are carbon track pots and don't use WD40 in this case.

[colorfixer]

Originally Posted by Josef

Nice, but I would j hook the copper wire to make the connection long term stable. In your case it could be better not to touch the connection any more to avoid further damage. I usually clean flybacks (from our european b&w sets) with WD40 to protect them from moisture and soften dried out isolations. Take care if there are carbon track pots and don't use WD40 in this case.

I would be really afraid of using something as explosive as WD40 near anything high voltage or capable of arcing.

[Electronic M]

Originally Posted by colorfixer

I would be really afraid of using something as explosive as WD40 near anything high voltage or capable of arcing.

WD40 isn't explosive as an applied coating...heck it won't even explode if you shoot the spray through the flame of a lighter as I have done... It'll just burn energetically and give you a nice flame thrower for toasting jumping spiders.

Wet WD40 isnt that easy to light either. Many years ago I was trying to fix a 30s fan that I eventually found had a bad contact brush and it was arcing like crazy but not easy to keep enough WD40 on the rotor to sustain burn for more than a couple seconds.