The LSD8 flash tube was designed for stroboscope use where the maximum flash rate of 500 Hz allowed examination of machinery rotating at up to 30,000 RPM.
A single flash can be up to 100 J, but for stroboscope use at a limiting dissipation of 30 Watts the energy per flash is in the range 1-5 J.
The discharge tube is formed by the central column and an outer tube. The trigger electrode is housed within the outer helical tube and connects at the base only.
The trigger wire can be seen at the top of the outer tube. The main discharge tube is discoloured with use.
The trigger wire is clearer in this image and the centre connection is to the discharge tube cathode.
The wide glass tube envelope is 38 mm in diameter, and excluding the UX4 base pins is 110 mm tall.
References: Data-sheet & 4095. Type LSD8 was first introduced in 1949. See also1949 adverts.
