What do you know about the 23D4?

[Captn Dave]

I picked up close to a cubic yard of tubes at a sale a while back and just yesterday I discovered some Amperite 23D4 triodes. At least I think they might be triodes.

They have Octal bases and are about the size of a 100watt bulb.

None of my manuals mention this tube and I have not been able to search for anything useful. (It doesn't help that Lucas made a distributor with that designator)

Anyone familiar with these?

 

[Tom Bavis]

Amperite made ballast tubes and delay relays - either should be fairly obvious.

 

[Wavebourn]

23D4 is a ballast tube, like a light bulb carefully engineered as a current source.