Philco 86 Pwr Trans - Printable Version
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Philco 86 Pwr Trans - RadioDR401 - 03-05-2018
Does anyone know if a power transformer for a model 87 will work in a model 86? The schematics look almost the same.
RE: Philco 86 Pwr Trans - morzh - 03-05-2018
Well.....philament voltage for 71A is 5V at 0.25A and for 45 is 2.5V at 1.5A, so the "C" winding is different. Otherwise it would work.....
RE: Philco 86 Pwr Trans - RadioDR401 - 03-06-2018
Thanks for catching this morzh. I didn't dig deep enough and wrongly assumed the filament voltages would be the same.
RE: Philco 86 Pwr Trans - morzh - 03-06-2018
Dave,
What sucks that for the most part they are the same
Except the Pus-Pull section.
Then again, maybe you could fit the 45s into it instead of 71A
Could require some mods....
RE: Philco 86 Pwr Trans - Arran - 03-06-2018
The issue with the #45s is that they require more B+ voltage, and more bias I believe, I think you can use the same output transformer. It may be pretty close anyhow, the #45s run ar 2.5 volts but draw 1.5 amps, the 71As run at 5 volts but draw .25 amps, so the same winding with 1/6 the current draw. Are you sure that the original transformer has failed? Does it run hot, or smokes, or is open circuit?
Regards
Arran
RE: Philco 86 Pwr Trans - RadioDR401 - 03-17-2018
It's definitely shot. It looks like someone attempted to "repair" it before me and literally toasted the PT. The good news is that I found a stripped down 86 chassis on eBay that still had the PT on it. I took a chance and bought it for $30 and after I rewired the primary and CT leads it worked like a charm. Reinstalling it will take a while but it looks like I'm back on business.
RE: Philco 86 Pwr Trans - Radioroslyn - 03-17-2018
Sounds Great!