New '60s Philco Roundie

[Hagstar]

I have the answer- massive arc-over of the high voltage insulating cup under the high voltage rectifier. Ordered a new one.

[Electronic M]

Originally Posted by Hagstar

I have the answer- massive arc-over of the high voltage insulating cup under the high voltage rectifier. Ordered a new one.

Sometimes that can be fixed. I had a zenith color port set that arced through the bottom of the cup. My solution was to drill out the carbon arcing path then use Permatex gray silicone to fill in the hole...It worked well and was almost a free repair.

[Findm-Keepm]

Originally Posted by Electronic M

Sometimes that can be fixed. I had a zenith color port set that arced through the bottom of the cup. My solution was to drill out the carbon arcing path then use Permatex gray silicone to fill in the hole...It worked well and was almost a free repair.

+1 - works every time. The Silicone Rubber has a higher volts/mil rating than the plastic in the cup - the cup will go before the patch!

RTV3145 is the best for HV applications - it's electronic grade, self wets, and cures in 6 hours or less. Navy avionics owes it's success to RTV3145 - it solved many arcing problems in F-14 (AWG9) radar power supplies, sealed chaff buckets, and I used it to cure arcing in a Conrac monitor used in the CATIIID bench that troubleshot modules. Great stuff.

[DavGoodlin]

Originally Posted by Findm-Keepm

+1 - works every time. The Silicone Rubber has a higher volts/mil rating than the plastic in the cup - the cup will go before the patch!

+2 a similar repair is still holding in a 16" Zenith color portable. There was a full metal cap behind the HV rect cup, drilled out the pinhole the arc made and plugged and coated the cup bottom with black RTV.

[Hagstar]

Fixed high voltage issues. Just rough convergence so far but finally an okay picture My next puzzle is that the AGC doesn't work though the pot seems to measure and function normally. Only just the right fairly weak signal makes an image, it overloads at the drop of a hat.

https://www.youtube.com/watch?v=Uj-wk-OtwzE

John H.