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Philco Model 20 rebuild - thanks for all the info
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I appreciate this forum. In searching through all the past posts about audio quality on the model 20 I found several good bits of information. The first I did not have to worry about. The spider had been replaced at some point in the past and the speaker re-coned. Both were a pleasant surprise to me. The next useful part was about the detector circuit. I was getting distortion in the audio and read about the modulation levels of early radios so I dropped my transmitter to 25% modulation and cleared that up. Then the reminder about line voltages back in the 30's so I dropped my bench variac to 115 volts.

End result is a very acceptable sound quality. Not as good as some of my other radios but acceptable. I have been wanting to add a model 20 to my collection but so far just had a spare chassis that was too rusty. The spare came in handy by supplying the dial, an rf transformer and the speaker pig tail. It was very nice to have the parts on hand!

Thanks!

Rick


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Philco Model 20 rebuild - thanks for all the info - by black85vette - 12-16-2017, 08:07 PM



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