[davemc]

I am working on restoring a Philco 38-39. Does anyone know what dial lamp is supposed to be used? The schematic shows the lamp in parallel with a 16.7 ohm resistor and both in series with the 1J6 output tube and an 8.3 ohm resistor across 6 volts. The 1J6 draws 240ma at 2 volts. The 8.3 ohm resistor drops about 2 volts at 240ma. That leaves 2 volts for the pilot lamp. The only 2 volt bulb I know about that is available is a #49, which is a bayonet based 2 volt 60ma bulb. If the bulb voltage is 2 volts, then the parallel 16.7 ohm resistor draws 120 ma. So the parallel combination would draw 120ma plus 60ma for the bulb, or 180ma. So that does not compute! The parallel combination needs to draw 240ma at 2 volts for all this to work out. Thus it appears I need a 2 volt 120ma bulb! Never heard on that. Was it a Philco-specific part? If so, I'm sure it is no longer available!

I suppose I could change the parallel resistor to draw 180ma and use a #49 bulb. But I'l bet it would be dimmer than the original.

Thnks!

[rghines1]

There is a type 49-A lamp at 2.1V @ 120mA (Bayonet) looking at the chart in the link below.

http://www.nostalgiaair.org/References/lamps/