The UABC80 is a triple diode triode in a miniature envelope and this exhibit was made by Mullard in England with yellow lettering from the Mullard Golden Jubilee year in 1969.
The three box sections with heaters connected at the top. The triode is on the left.
This image offers a better look at the heater connections.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins, is 55 mm tall.
References: Data-sheet, 3002 & 1040. Type UABC80 was first introduced in 1952. See also1952 adverts.
