Sensibly equivalent¶ to:
The EL38 was designed as a television line output stage valve in the late 1940s. In the early days of CRT based television the tubes could have been either electrostatic or magnetic deflection. The EHT supplies were probably derived from special mains transformers and ran at about 10 - 14 kV. Thus the line output valve was not as heavily stressed as later types had to be.
The EL38 was designed to withstand a positive anode surge of 8,000 Volts and in addition to the 25 Watt anode dissipation the screen grid was wound to withstand a dissipation of 8 Watts. The cathode is oval, and the ceramic insulators are clearly visible.
The classic envelope is 41 mm in diameter and, excluding the IO base pins, is 115 mm tall.
References: Data-sheet & 1040. Type EL38 was first introduced in 1946. See also 1946 adverts.
Absolute Maximum Operating Conditions¶
Updated January 05, 2022.