Robert Eidt
Forum Participant

I fired up the Philco 40-165 today! …but it still hums. The volume control does not affect it and it’s not real loud but definitely too loud. I also cannot tune any station. It sounds like an AC issue, but I’m sure the recap job is good. When I bought this I was told it hums.

I checked my recapping job around the power supply area in particular and all is where it should be. I think it would have been hard to mess up with a schematic in front of me and the old electrolytic wires still attached at the time of the recapping, but I checked everything in the area against the schematic to be triple sure. While checking some resistors I noticed the 470000 Ohm (item 45) is reading 523000 ohm. This is actually the Canadian “model 23” so maybe it’s correct. It’s in the area of tube 41E, but the biggest thing I notice is I can’t see any light in tube 41E and it doesn’t get hot.

Should I be able to see and feel the heater glowing in this particular tube?
I’ve read that a failed filament can touch the cathode and cause a hum. Is this common?

I guess my biggest question is “should I be able to see a glow in 41E. If so, I know what I need to do next. If not, Have you any ideas?

I do read 3 ohms between the two fattest pins and I know one is the filament, but I don’t know where the ground is. I have no tester.