The wartime Hytron Corporation worker shown here is using a tube tester, but it’s probably a bit bigger than the one down at the drug store. She is operating a master test station for measuring various attributes of transmitting vacuum tubes. It was described in the October 1944 issue of Radio News.

A year later, the editors were undoubtedly looking for a stunning picture for the cover, so they went ahead and used it 75 years ago this month, in the October 1945 issue.

The test station had various power supplies, as well as precise measuring instruments for voltages and currents to each tube element. The nicely crafted drawers provided storage space for jumper cables and adapters. The heights and angles of all of the meters were carefully considered to avoid paralax errors.

Hytron was acquired by CBS in the 1950’s, and was a major producer of tubes under the Hytron CBS label.

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