Hytron, Salem (MA) is a well known tube (and also semiconductor) manufacturer.

Headquarter in Salem, known facility in Lowell (MA).

In the early 50s Hytron was purchased by CBS (Columbia Broadcasting System). By late 1952, CBS was manufacturing germanium diodes and transistors at the Hytron facility in Lowell (MA). Various device types, labeled as "CBS" or "CBS/Hytron", were in production for approximately 10 years (until the early 1960s), when CBS exited the semiconductor manufacturing field.