|I just finished overhauling this Philco 90 with the single 47 output tube. It has reception and wants to pull in stations across the dial. But the volume stays the same no matter where the volume control is positioned. I put a screwdriver on the CT of the VC and I get a very audible hum from the speaker. Audio circuit is good? I wonder if I have a bad volume control? The only anomally I can find in the set is the voltage at the plate of the Det. Amp. Paperwork is a little fuzzy but it looks like I should have 140Vdc there. I have 54Vdc.