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Joined: Dec 2009
City: Roslyn Pa
Seems like 1/2 of your interstage transformer is open. This is why the plate voltage on your 71's isn't more even, one tube has no grid bias and it's causing the plate to draw more current. Just to confirm measure the resistance from each 71 grid back to the center tap of the transformer. Should see a fairly low resistance 1K or less.
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
(This post was last modified: 06-19-2017, 10:18 PM by Radioroslyn.)
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RE: Philco Model 20 Lowboy - by Radioroslyn - 06-19-2017, 10:18 PM
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