Abstract :
In the first section of this paper cooled-anode valves of the transmitting, modulating and rectifying types are described, with details regarding construction and pumping. Characteristic curves are given, and in some cases particular applications are considered. The second section deals with various factors which affect the lives of valves. The importance of the life of the valve cathode is emphasized, and means of obtaining the maximum life from the cathode are described. In the last section survivor curves are given for various types of radiation-cooled valves, showing actual results obtained on commercial stations. As such data are not yet available for cooled-anode valves, extracts are given from valve records of stations using these valves.
