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Philco 40-140 Field Coil Replacement
#39

Radiola, again, assuming no objectionable hum all is well. It might be interesting to see what the B+ is after the dropping resistor just to see how closely your resistor matched in reducing the B+ to the original field coil if you have any voltage levels indicated in the schematic. You should be set to go. Most all of the later tube radios like the AA5s never used a choke and had permanent magnet speakers, so no field coil. Generally they had higher value electrolytic caps to make up for the loss in filtering and most important, keep the cost of manufacturing down.
Bear in mind, I'm not the sharpest on radio repair but have a couple radios running speaker replacements using the resistor method and all have worked nicely for years.

Jerry

A friend in need is a pest!  Bill Slee ca 1970.


Messages In This Thread
Philco 40-140 Field Coil Replacement - by radiola - 09-04-2012, 11:21 PM
RE: Philco 40-140 Field Coil Replacement - by jerryhawthorne - 10-12-2012, 12:38 AM



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