01-14-2024, 06:24 PM
Hi Pat and welcome to the Phorum.
It could be the noise is coming thru the ac line and not the air if it is interference (not hum). There are a couple of other possibilities. A miswired cap from the ac voltage over to anything on the dc side of things. A short in the heater to cathode or cathode to grid in any of the tubes will give you a 60cy hum. An open grid circuit in the audio or somewhere else can produce a hum situation.
Try plugging the ac plug around the other way and see if that makes a change. Is there any sort of "ground" connection to the set, I know this thing is an ac/dc job.
Have fun chasing electrons!
de N3GTE
It could be the noise is coming thru the ac line and not the air if it is interference (not hum). There are a couple of other possibilities. A miswired cap from the ac voltage over to anything on the dc side of things. A short in the heater to cathode or cathode to grid in any of the tubes will give you a 60cy hum. An open grid circuit in the audio or somewhere else can produce a hum situation.
Try plugging the ac plug around the other way and see if that makes a change. Is there any sort of "ground" connection to the set, I know this thing is an ac/dc job.
Have fun chasing electrons!
de N3GTE
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 it!
Terry
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