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Philco 111 schematic question.
#1

I'm currently restoring Philco Lowboy 111. I am having difficulty comprehending this schematic, particularly rectifier and plate voltages. It seems to me that -VDC is fed from the center tap of the transformer into the field coil and then connects directly to the +VDC line coming from the rectifier tube. Also, it looks like -VDC goes to all tube plates and I'm not sure how that works. I marked the negative in yellow and positive in red. Could someone tell me what am I missing here? Thank you.


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#2

Hi,
What you are missing is the ground symbol next to 57. Everything to the left of the symbol  is - voltage and everything to the right is +voltage. D and E are - bias voltages for the detector and the audio output stages. Easy peasy! [Image: https://philcoradio.com/phorum/images/sm...iggrin.gif] You might find this : https://philcoradio.com/library/images/schem/111.jpg diagram easier to work with as it as the pasts values noted.

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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