Cossor made these double signal valves as both the Type 6AL5, American identifier, as here and as the EB91 the European identifier. This exhibit has white lettering.
These double diode valves were designed for vision and sound detection in television receivers. Additionally they are recommended for limiting and DC restoration. Each section is internally screened.
The stitched anodes are held between upper and lower mica sheets.
The twin diode sections with electrostatic screen between.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 45 mm tall.
References: Data-sheet & 1040. Type 6AL5 was first introduced in 1945. See also1945 adverts.
