COLOR CRT MANUFACTURING in the Mullard Plant

[Tom_Ryan]

Originally Posted by Eric H

He calls the little plates control grid cooling fins but would "cooling fins" really work in an airless environment?

Yes. Eric, in vacuum tubes virtually all anode heating comes from the kinetic energy of electrons striking the anode. The actual resistance of materials in the anode (and other elements in the tube) is very low, and the relatively small amount of heating is dwarfed by electrons impacting the surface of materials in the tube, including the control grid. Those little plates help to dissipate heat given off as infrared radiation, which passes through the vacuum and is absorbed by the glass neck, or envelope, of the tube, ultimately transferring to the surrounding air on the outside.