Philco 84 Restore - Printable Version

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+--- Thread: Philco 84 Restore (/showthread.php?tid=12800)

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Philco 84 Restore - markmokris - 07-31-2015

I am just finishing up a restore of a Philco 84 cathedral.  I had to rewind the primaries on the antenna and oscillator coils.  I replaced all the capacitors. I also replaced all the dogbone resistors. I have adjusted the regeneration control, and peaked the IF capacitors.  It is playing with pretty good volume with only an 8 ft. piece of antenna wire.

I need to still make the 2 meg ohm resistor change from the service tip in the IF transformer to see if it plays even better.

Question...I noticed that someone had removed the "gimmick" capacitor (#3) so I replaced it.  It seemed to make no difference.  What exactly is the capacitor doing?  Coupling a little extra signal from the antenna to the oscillator?

Why would it seem to not be needed?

   

Thanks,

Mark K8KZ

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RE: Philco 84 Restore - GarySP - 08-01-2015

Hi Mark.  I have that same gimmick cap in my 41-280.  My guess is it works as a filter.  I don't know exactly how, but others on this site can offer more info than I can.  All I know is that I was told to keep it in the circuit or you can pick up a lot of "white" noise.  Take care, Gary

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