Production Testing of Vacuum Tubes

The factory testing of vacuum tubes is becoming more specialized every year. In the early days of broadcasting a few tubes served many purposes and actual performance in its relation to tube characteristics was not as widely studied and understood as it is today. Increasing knowledge of the how and why of tube and set operation has led to the development of many more or less special tubes designed for a specific function in the set. The increasing use of accurate set measuring equipment has enabled. designers to work out the optimum circuit arrangements for the use of these specially designed tubes in the various stages. As a result of this growth of the industry the testing of vacuum tubes has required more and more attention to set operation, a constant elaboration of test methods and equipment being necessary in order to exercise the necessary control over tube characteristics.