Sensibly equivalent¶ to:
7971 CV4060 CV8077 L.5B/280K
The S11E12 is a special quality version of the 12E1. It is rated as an output valve but the reference books do not make it clear that this valve was specially designed for use as a series pass element in a voltage regulator.
This valve has the classic STC logo on the glass but the later S11E12 has the letters STC picked out in bold caps.
The wide glass tube envelope is 38 mm in diameter and, excluding the IO base pins, is 80 mm tall.
References: Data-sheet & 1040. Type S11E12 was first introduced in 1959. See also 1959 adverts.
Absolute Maximum Operating Conditions¶
Updated October 24, 2016.