The valve characteristic tables on the following pages are as complete as possible. Many types, although used in thousands of sets, are no longer made. Alternatives can be chosen from a study of the characteristics, and of the bases.
The tables are subdivided into frequency changers, triodes, etc., and these appear approximately in the order in which they are used in receivers.
Order of presentation
Within each subdivision valves are listed in the alphabetical order of the manufactures’ names (Brimar, Cossor, Dario, etc.). Thereafter they are dealt with in ascending order of filament or heater voltage, which in general means that battery valves come first, followed by AC-only types, then those ...