1920s GORDOS G83 POWER DIODE VACUUM TUBES FROM MY ATTIC

[nightfly61]

I have 5 of these & they look like big light bulbs with wire coming out the top of the globe. I got them from an old movie theater projector's rectifier. I was curious if there's a way to test these, since there's no large screw in jack that big on my tube tester. All of them have the little coil of wire still in tact inside so I guess that's a good sign. They look like when fired up they could heat a small room. Anyone familiar? Thanks!

[Chuck]

From your description, I think they are mercury vapor rectifiers. They used to use them in battery chargers.  In this case, they probably were used to provide DC for the projector's arc lamp.  Any, yes, I think you could heat a room with a few of them.

I don't know how to test them other than a continuity check of the filament across the Edison screw base.  As long as there is continuity, the bulb still has a vacuum and the mercury is in there, they ought to work.

[Lane_Lindstrom]

Yes Tungar tubes. They were commom as mentioned in old battery chargers.