09-04-2016, 10:23 PM
No your missing the driver transformer(#83). Unless there is phase inversion circuit the output stage isn't going to work properly. It may have been rework to have a resistor in the plate circuit of the 42 driver tube (to act like the transformer pri) and capacity coupled to the control grid of one the 42 output tubes. The other 42 control grid might be connected to the the screen grid of the first 42 though a cap. Much like the late 30's and early 40's philcos. The problem it that the original set up the 42's have the screen and plate connected together in a triode configuration in what Philco their super class A 10w audio output stage.
Any way what you have is a mess but it can be fixed by replacing the driver transformer with https://www.tubesandmore.com/products/tr...i-158k-sec
Simple enough to wire it like the original and dig up a cover to cover this replacement.
From the top I looks just like my 660 AAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Terry
Any way what you have is a mess but it can be fixed by replacing the driver transformer with https://www.tubesandmore.com/products/tr...i-158k-sec
Simple enough to wire it like the original and dig up a cover to cover this replacement.
From the top I looks just like my 660 AAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Terry
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
