09-04-2024, 12:33 PM
Just another update. Because of several tubes that were DOA, I started to check the power transformer windings for the correct ohm readings. When I checked the HV secondary, my VTVM showed the hallmark reading of a leaky capacitor charging. This should not happen as the HV secondary is isolated from the filter circuit. I did some poking around the rectifier socket and found a burn mark. When I poked at the burn, my probe went through the phenolic right between the plate connections for the 80 rectifier. I suspect the burn allowed a path to the filament connection, which would allow a connection to the filter circuit. Anyhow, since the socket has to be replaced, it seems better to replace it with an octal socket and replace the 80 with a 5Y3. Any advice as to the type of octal socket, ceramic, plastic? I may be able to get an octal socket from my local Vetco Electronics.
It looks as though someone replaced the line cord at some point. Not sure, but I don't think it was done correctly and that, coupled with a leaky filter capacitor may have caused arcing that burned the socket. I will be checking the other sockets for burn marks.
Thanks!
Rich
It looks as though someone replaced the line cord at some point. Not sure, but I don't think it was done correctly and that, coupled with a leaky filter capacitor may have caused arcing that burned the socket. I will be checking the other sockets for burn marks.
Thanks!
Rich