The Z14 is a variable μ RF pentode for dry battery operation used for domestic broadcast receivers at RF or as an IF amplifier. The filaments had to have the lowest possible consumption due to the cost of the dry batteries.
The Osram paper label.
The pinch construction places all connections in line. The outer perforated screen has shaped mica sheets that hold the assembly firm within the envelope.
The filament tensioning spring can be seen on the left. At the base is a screening disc.
The wide glass tube envelope is 28 mm diameter, and excluding the IO base pins, is 81 mm tall.
References: Data-sheet, 1040 & 1043. Type Z14 was first introduced in 1940. See also1940 adverts.
