Philco Debutante issues

[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.