[dconant]

Hello, Still messing with this radio. The 42 tube was weak and played well so I though I would just leave it be. Did not notice any appreciable hum at the time. I decided to replace the tube and now I have lots of hum. I'm pretty sure it is 60 cycle hum. The volume control has not effect on the hum, It is not the 42 tube that is the cause as I have tried 3 others. If I disconnect the wire to pin 4 (grid) of the 42 tube the hum is gone. If I touch pin for with metal object I get a hum as expected. I connected the wire back up and then disconnected the wire at the plate of the 75 tube and the hum is still present. Disconnecting the 70k (#59A) resistor at the .02 (#59) junction does not effect the hum. After disconnecting the 500k (#58) resistor the hum is gone. So this make me wonder about the 10uf (#67) ecap. I have it wire as positive ground. Is that correct? If it is then what may be the issue here. I recapped the whole radio. Also removing all tubes except the 80 and 42 make no difference. Doubling the ecaps one at time made no difference either. The one thing that bothers me is the field coil reads 678 ohms where the schematic say it is supposed to 1140. The speaker list on the Philco site says the K-32 speaker DC resistance is 435. 

Dan