philco 41-240 (121) - Printable Version

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+--- Thread: philco 41-240 (121) (/showthread.php?tid=7033)

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philco 41-240 (121) - sam - 07-11-2013

hi guys
in my 41-240 power trans former sits in a black can, looks like brown shalac all over it. dose not smell burnt but has that look and around mounting bolts are black. thinking it is bad ?
readings should be = are
13.5 = 19.0
.2 = .8
300 = 297.6
320 = 272.4
i think thats right as i am still learning schmatics p.s. colour blind so cloth wires look the same to me
thank for your help
sam

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RE: philco 41-240 (121) - Radioroslyn - 07-11-2013

Probably not. Pull out the 7Y4 and turn on the set and measure the AC voltage between the chassis and pin3 and then pin 6 of the 7Y4. Should see about 300vac from each of those pins to the chassis. If you do and the other tubes light your power trans is good. Do not try to operate the set with the 7Y4 till the filter caps have been replaced!
Terry

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RE: philco 41-240 (121) - Arran - 07-11-2013

Those resistance measurements aren't too far off the factory spec, though the one reading 272.4 seems a little low if the actual is supposed to be 320. A shorted high voltage winding will have one side substantially lower then the one on the other side of the center tap. A shorted H.V winding will also cause the transformer to heat up even without a load. What you need to check is the voltages on each side of the H.V winding as Terry suggested, they should be pretty close to equal, maybe withing 5 to 10 volts. These sets do cook transformers from time to time but less often then their brand Z counterparts from the same era.
Regards
Arran

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