[Chuck Schwark]

Thanks guys! Got it.

I pulled the schematic from philcoradio.com on this Philco 90 with all of the component values added. My Philco 90 (single 47 output) has a 250K volume pot in it and the part number 5366 is on the volume control which matches the parts list. But the schematic calls out a .5 meg pot. Is this a discrepancy on the edited schematic or is my volume pot not functioning properly? It seems to be functioning properly with my Fluke 179 hooked up to the CT and each leg but reads 250K across it.

Pepper

All my Philco Parts Catalogues show the volume pot to be Part No. 5724 for the 1-47 tube version, which is 500,000 or 0.5 meg pot. Part No. 5366 only shows up in my 1945 Parts Catalogue as subbed with p/n 45-5019 (a 1945 version part) with also a value of 0.5 Megohms.

From all this info, it appears that 0.5 meg for the pot is the correct value. The schematic (90 w/1-47) on this site also shows Part No. 20 as 0.5 Meg.

Be sure you are measuring the resistance of the pot from the outer two terminals, not from the each end to the center terminal, which is the wiper.

Regards,
Chuck