Audion_oxide-filament

The element structure of this tube is very similar to that of the de Forest Oscillion tube. It was designed to have a lower anode dissipation. The change in bulb shape from spherical to tubular enaled this heating allowed this. The tube had an oxide filament. The first tube designed was fitted with an E12 (Edison Screw) base. It is understood that the base was changed to the special Navy 3 pin bakelite base in 3 developmental tubes as well as the final tube. This base was used on the US Navy CF185 tube. It is not known if the tube was given its own type number. An adaptor was made so that the 3 pin tube could fit a UV socket. The final development of the tube had a UV base, with all 4 pins used.as normal..