Reliability in Miniature and Subminiature Tubes

The meaning of the term "reliability" as applied to electron tubes is discussed, and the thesis is developed that reliability is a function not only of tube design and quality but also of the relationship between tube ratings and the operating conditions and requirements. Specific features of the miniature and subminiature tubes are discussed with respect to factors affecting tube reliability, such as mechanical ruggedness, operating temperature, emission stability, and life. General comments are made on the over-all effect of reduction in tube size on life and reliability.