Philco 81 Front End Problem

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02-02-2009, 10:00 PM

Thanks Exray. I did the test with the second radio (Philco 41-226). When the Model 81 was dead, there was no oscillator sound in the second radio. I removed the grid cap from the 1st detector and the Model 81 started to oscillate and could be heard in the second radio. So we now know that we have a problem with an oscillator that fails to start. I have tried swapping the two #77 tubes, and that didn't help.

Disconnecting and reconnecting the antenna doesn't help. Disconnecting the ground doesn't get the oscillator going. Switching to police band doesn't get the oscillator going.

Now the Model 81 is oscillating and I can't get it to quit. It will probably have to cool down for a while.

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Philco 81 Front End Problem - by Guest - 02-02-2009, 07:56 PM

Re: Philco 81 Front End Problem - by exray - 02-02-2009, 08:41 PM

Re: Philco 81 Front End Problem - by Guest - 02-02-2009, 10:00 PM

Re: Philco 81 Front End Problem - by exray - 02-02-2009, 10:45 PM

Re: Philco 81 Front End Problem - by Steve Davis - 02-02-2009, 11:12 PM

Re: Philco 81 Front End Problem - by Guest - 02-05-2009, 08:48 PM

Re: Philco 81 Front End Problem - by Guest - 02-06-2009, 06:45 PM

Re: Philco 81 Front End Problem - by exray - 02-06-2009, 07:01 PM

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