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Philco Model 66 restoration
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I recently purchased a Philco Model 66. It was pretty well hacked up by someone. I now have the chassis restored to original and it pulls in station really great. However I am having a problem with two resistors. One is #47, which is a 37K resistor, which looked to be about 3W. It was way up in value. I replaced it with a pair of 75K 2W flame proof resistors in parallel. Then Resistor # 15 32K, I replaced with a 33K 1W carbon type. I have no idea of what the original wattage was. Someone had installed a 39K 1W resistor in its place and it had gone up in value. After the radio plays for between 5 and 10 minutes, you can't put your fingers on the 37K # 47 and the 32K #15 is also to hot to want to keep your fingers on it. Everything except the 6A7 tube has been replaced and I used my VTVM in the high meg scale and checked for high resistance to ground, which would indicate a short. None show up. Naturally capacitor #49 takes a charge when doing this so I disconnected it to make sure. All capacitors, except the micas have been replaced by new capacitors. All off value resistors have been replaced. I did have to install a replacement choke because it was missing. I used the exact part that Philco called for. I can tell by the discoloration on the small board where resistor #47, the 37K is mounted, that the original ran hot. When I pull the 6A7 tube, the 32K resistor #15, remains cold, resistor 47, the 37K is barely warm after 5-10 minutes. The only thing these two resistors have in common is the 6A7, however even after leaving it heat up at a higher filament voltage, in the tube tester it still tested good. I do not have a new one to try. Does anyone have any ideas? Would anyone know the correct wattage for the 32K resistor #15? Thank you guys.


Messages In This Thread
Philco Model 66 restoration - by Tubesforme - 05-31-2017, 02:14 PM
RE: Philco Model 66 restoration - by morzh - 05-31-2017, 04:05 PM
RE: Philco Model 66 restoration - by dacsman - 05-31-2017, 04:12 PM
RE: Philco Model 66 restoration - by Tubesforme - 05-31-2017, 06:17 PM



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