Sensibly equivalent¶ to:
The acorn valves were designed to have low capacitances and therefore work to higher frequencies than the normal valves. The 955 triode was introduced in 1934, and has a 6.3 Volt heater.
The valve is marked JRC955, the JRC marking being a US Government quality code.
The 955 was later re-issued on a B7G base as the 9002.
Radio amateurs used acorn valves for work at 144 MHz after WWII.
The acorn envelope is 14 mm in diameter and, including the base pins, is 32 mm tall.
References: Private Communication & datasheet. Type 955 was first introduced in 1935.
Absolute Maximum Operating Conditions¶
Updated December05, 2016. shape:acorn construction:all.glass type:triode age:1930.1940 base: heater:6.3v pins:5 pin:1.f pin:2.a pin:3.g1 pin:4.f pin:5.k