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American Bosch model 515.
#1

Icon_problem Audio output transformer has open primary. output tube is a 42 and schematic about 3 watts+/- of power. any suggestions as to what I need to replace the transformer Icon_confused:
#2

Pretty much any output transformer used with a another 42, a 6F6, 6V6,or even a 6BQ5 will work as a replacement, there are others of course but the plate impedance is pretty close between those tubes.
Regards
Arran
#3

Icon_wave thank you for advise--will do.
#4

Or if you want to live life on the edge you can use a 6.3v filament transformer. the 110v side goes to the plate circuit and the 6v side to the speaker.
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
#5

Agree with all, you'll get some audio if everything else is OK. Then you can fine tune it and get a proper transformer




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