This is a most unusual triode with small Edison Screw connectors at either end. There are no markings and it remains a mystery.
The filament is a single self supporting V with both ends attached to one end cap. The grid and anode are also supported at one end only.
The sheet anode is folded over to enclose the support rod.
The anode is not a closed cylinder and the helical grid can be seen within. The wire diameter of the grid is substantial. It can be seen that the filament is broken.
The broken end of the filament.
The wide glass tube envelope is 25 mm in diameter, and including the bases is 117 mm tall.
Updated December29, 2014. shape:wide.glass.tube construction:pinch type:triode base:es pin: