EP33
From Night Vision Wiki
The EP33 is a generation 0+/1 image intensifier tube of Russian origin.[1] All variants of the EP33 are produced by Ekran. There are multiple variants of the EP33, these are: EP33, EP33-U, EP33-UD, EP33-US-D and EP33-SF. The SF is special, as it has a spherical photocathode to counteract distortion.[2] These tubes were and still are widely used in civilian devices marketed as "generation-1". The U in some EP33 variant indicated that the anode cone is shortened for the sake of compactness.[3]
