Museum of the Broadcast Television Camera

Image Orthicon Dynode Structure

Image Orthicon Dynode Structure

A close up of the dynode structure of a 3 inch tube. This worked on the same principle as an electron multiplier photo electric tube.

 

An increasing voltage was applied to each dynode step with some 1250v on the final one. An electron in the return beam from the target striking the first dynode produced a shower of electrons which then struck the second dynode and the cascade of electrons were collected in the final dynode as the tube output. Considerable and adjustable, gain could be archived.