Simple production methods for dynamic testing of horizontal-deflection tubes

By the time television deflection circuits had become an important tube application, it was known that conventional static-characteristics and trans-conductance tests of tubes did not correlate well with deflection output. Furthermore, some tube defects peculiar to deflection-circuit operation were not apparent during such tests. Until recently, therefore, the quality of tubes for this application was checked by means of operation tests in a deflection circuit. Although such a test has merit, particularly for checking characteristics such as microphonics, considerable engineering time was consumed on the design of the test set and the deflection-circuit plug-in boxes for each tube type.