Field coil on Philco 38-12 - Printable Version

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+--- Thread: Field coil on Philco 38-12 (/showthread.php?tid=23551)

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Field coil on Philco 38-12 - Tubeglow20 - 05-27-2022

I have begun restoring a Philco 38-12 radio and have a question that I hope I can get an answer to on the phorum The speaker in this radio uses a field coil with a resistance of 1.5k ohms according to the schematic. I have completely disconnected the coil from circuit and when I measure the resistance I get approximately 6k ohms on my multimeter. I have been told that the 1.5k ohms shown on the schematic is the impedance of the coil and not the DC resistance. I restored a Philco 39-6 and the schematic showed 1.7k ohms and the coil showed approximately 1.7k +/-. So my question would be, is the coil shorted and needs replacement, or is it ok as it is?

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RE: Field coil on Philco 38-12 - morzh - 05-27-2022

if anything, DC resistance is smaller than the impedance to AC current.

If it says 1.7K, it should measure 1.7K. Not 6K.

A shorted coil would be 0 Ohms, not 6k.

If it measure 6K, it is possible it is a different speaker altogether or the coil is bad.

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