Help Identify this Tube/coil

I received a small box of tube from a friend and one of them was rather strange to me.

It is a Crosley G3-51014. It is an octal base tube with a coil inside and no heater!

Would it be a ballast ? ..... Gregg

I have seen it suggested elsewhere that it is an oscillator coil for a Roamio, but I have not been inside a Roamio.

Dale H. Cook wrote:I have seen it suggested elsewhere that it is an oscillator coil for a Roamio, but I have not been inside a Roamio.

I've seen that also but could not find it on any schematic.

MEZLAW wrote:I've seen that also but could not find it on any schematic.

I looked through some of the Roamio pages in Rider and I didn't see anything promising either.

If it looks like a plug-in RF/IF coil then I think it likely that it came out of something that Crosley built for a military contract. I can't really imagine them building something with removable coils for civilian use. AFAIK they did not build amateur gear. Can you post some pics?

kb4yrc wrote:Would it be a ballast?

I am quite sure that if it were a ballast he would have recognized it as such.

Just for informational purposes, a ballast would have vertically mounted coils of resistance wire. I have had a couple of solonoids in vacuim tube glass. There's a coil, and, contact switches. Most commonly used on equipment where dirtry contacts would cause major issues, such as in transmitters.

One more bit of information, all of these tubes in the box were used in early (1930's and 1040's) automobiles.

Definitely looks like a plug-in oscillator coil...

But why...and for what.......?

I would think for Military applications it would be more robust then just a glass envelope and for civilian applications, why would you need the ability to change out this coil on-the-fly?

After seeing the picture, I'd have to agree. It's an oscillator coil. But, unusual.

It is an oscillator coil, but I cannot find one on a Crosley schematic as a plug in. I agree the big question is why?

I guess the next step is to see what kind of equipment Crosley built tor the war dept./DoD.