The DY51 is an EHT rectifier designed as a replacement for use in portable television receivers. At this time all such receivers would be black and white only.
The bell anode. Rounded edges are present to minimise the possibility of a flash-over.
The oxide coated cathode tube is connected to one side of the heater.
The thin glass tube envelope is 13 mm in diameter, and excluding the base wires is 55 mm tall.
References: Data-sheet & 3002. Type DY51 was first introduced in 1964. See also1964 adverts.
