11-09-2020, 11:04 PM
Well, I may be wrong, but page 16 of the 1937 Philco List Parts catalog on this site says the bulb bead should be white, indicating a 2.5 volt bulb, not a blue 6.8 volt bulb. The bulb voltage is taken right off the heater 2.5 ac line; I always thought it looked dimmer than it should be - and tried cleaning the socket to no avail.