The EF50 was designed in 1938 by Philips of Eindhoven for Band I television receiver use and first released in 1939. It was extensively used in radio and radar during WWII as one of the few designs that could amplify wideband signals at 45 MHz.
The Sylvania name and Made in USA.
Another code.The wide glass tube envelope is 33 mm in diameter and, excluding the B9G base pins, is 61 mm tall.References: Data-sheet & 1040. Type EF50 was first introduced in 1939. See also 1939 adverts. |
