[davemc]

The 37-624 is a 6 volt set. The pilot lamp is in series with the 1C7 and 1J6 tubes, both which need 2 volts at 240ma. The pilot lamp is shunted by a 16.7 ohm resistor, which means it needs to be 2 volts at 120ma, since the voltage table says that the 1C7 and 1J7 filament voltage is 2 volts each and the supply is 6 volts.

The original lamp was not marked, and was destroyed getting it out of the typical Philco pilot lamp socket mess. But it was a bayonet type and tubular shape or T-3-1/4 type.

I don't see a lamp rated 2 volts at 120ma in my catalogs. The #49 is rated at 2 volts at 60ma, but is a globe type.

Anybody know what lamp I should use? I hope it's not one of the rare types no longer available.

Thanks!

[rghines1]

Can you see the lamp's bead color?

Another thing is the 1J6 plate current also passes through the lamp and resistor. Max current is 50 mA per plate (100 mA total) according to the tube manual. Expect it would average about half that, 50 mA altogether.

Google search on the Philco part no. was no help.

Richard

[Chuck Schwark]

In the 37-624 Service Bulletin, the pilot lamp, part no. 62 is a Philco Part No. 34-2150 which, according to my parts chart, is a 2.1 volt, 120 ma. bayonet based lamp. An odd type, not equivalent to any contemporary lamp number. See the Pilot Lamp Chart on my site in the PHILCO RADIO PARTS VALUES section under Pilot Lamps.

Maybe use a 6 volt lamp to fit the socket and rewire it to a 6 volt point in the schematic.


Chuck