[Radionut78]

Can someone advise a good book that describes the different components of vacuum tubes? I would like to know what a "getter" is and how to distinguish the various types. Also, how do you tell the difference between a tube with smooth plates and one with ribbed plates? I have a copy of the book "Tube Lore" by Ludwell Sibley but it does not contain information of the components or how to distinguish the difference between the various types. Thanks for any and all help.