09-16-2018, 04:51 PM
If the hum happens after it's been on for a few minutes and not when you 1st turn it on I would suspect a bad tube. Leakage between the heater to cathode or cathode to control grid could do it. Try removing each tube one by one and listen to hear if the hum goes away. Tubes in the audio output would be a little more likely to be the cause vs the others. Leave the rectifier tube in place, if you remove it the set won't do anything (no hv).
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
