The EY86/87 from mullard is a high voltage half wave rectifier. It was designed as an EHT rectifier in television receivers and instruments.
The reverse of the envelope showing the anode bell and heater connections and cathode support.
The oxide coated cathode tube can be seen in the centre of the anode.
The thin glass tube envelope is 21 mm in diameter, and excluding the base pins is 61 mm tall.
References: datasheet Type EY86/87 was first introduced in 1956.
Absolute Maximum Operating Conditions¶
Updated April 05, 2011. shape:thin.glass.tube construction:all.glass type:rectifier.hw age:1950.1960 base:b9a heater:6.3v pins:9 pin:1.h.k.s pin:2.h pin:3.- pin:4.k.h.s pin:5.h pin:6.h.k.s pin:7.- pin:8.h pin:9.h.k.s pin:tc.a