The 955 Acorn
The type 955 triode “acorn tube” is a small triode thermionic valve (vacuum tube in USA) designed primarily to operate at high frequency. Although data books specify an upper limit of 400–600 MHz, some circuits may obtain gain up to about 900 MHz…… More at Wikipedia
5 September 19 – Trivia Question
The Acorn Valve
An acorn tube, or acorn valve, refers to any member of a family of VHF/UHF vacuum tubes starting just before World War II. They were named after their resemblance to the acorn, specifically due to the glass cap at one end of the tube that looked similar to the cap on an acorn. The acorn tubes found widespread use in radios and radar systems….. More at Wikipedia