DeForest Audion DPDG
DC Amplifier Triode
1918

This is one of the last spherical audions, produced by DeForest in 1918 for the military. This tube is one of a very small number which used dumet in the press rather than platinum. At this time DeForest could not normally use dumet because of patent issues, but patent immunity was given to military suppliers during WWI.

 Click the back button on your browser to return to the thumbnails