Philco Debutante issues

[Zsuttle]

Hi all,
I recently finished restoring a Philco Debutante, which included replacing all of the resistors, electrolytics, networks, and all other mica, wax, and bumblebee caps. A few questions.

Someone was running the set with a 6AX4 instead of a 6DA4 as the damper, I know it's not a direct replacement, how compatible are the two? I replaced it, with a 6DA4, just to have it short out while I was adjusting the Horizontal. Not sure if it was a bad tube, or if it was the TV that killed it. It tests as shorted on every function on my TV7. New tube restored the HV.

Also, I recoated the flyback as it was missing half of the tar. Used the sensor safe sealant that everyone suggests. Worked great, but now it's buzzing with the new damper. Didn't see any arcing in the HV cage, any thoughts?

Lastly, the V lin pot was broken, but I found a 3kohm NOS philco pot, and replaced it while shunting it with 3k resistor to get the 1.5k required.

[Zsuttle]

I haven't been able to find the source of the buzzing. I tried swapping the 1B3, to no avail. I did replace the resistor underneath the tube, which makes me wonder if it's too close to something else underneath the socket. The buzzing intensity increases with the brightness control. All the way down, and it stops.

[old_coot88]

Originally Posted by Zsuttle

The buzzing intensity increases with the brightness control. All the way down, and it stops.

That would indicate an open gap somewhere in the pathway between the 1B3 and the CRT anode. The CRT beam current is forced to jump the gap as you raise the brightness. Check the HV lead itself for continuity. It might be open.

[Zsuttle]

Originally Posted by old_coot88

That would indicate an open gap somewhere in the pathway between the 1B3 and the CRT anode. The CRT beam current is forced to jump the gap as you raise the brightness. Check the HV lead itself for continuity. It might be open.

Ok, thank you, will check it tomorrow. I never would have suspected the cable itself

[Zsuttle]

I checked the cable, and I'm getting solid continuity. I swear the sound was coming from the tube itself. It was coming from the HV cage, around the tube, but didn't appear to be coming from the flyback.

I should also mention that everything was going fine until the damper shorted out. Then I lost the HV, and replaced the tube, but then the buzzing or sizzling started.

[Zsuttle]

Finally found the issue, but have been unable to remedy. I removed the 1B3 socket and fired it up outside the cup. As soon as the HV came up, I saw arcing between the pins of the socket. There was also arcing from the pins to the body of the resistor itself. I tried bending things out of the way, and tried coating with super corona dope, but have had no success. Any idea how to get it to stop arcing?

[Electronic M]

Could there be poor continuity between the socket contact and the tube pin causing another in used pin tied to the same tube element to arc to the connected socket pin?