This exhibit is an ML6C (with ceramic base) of WWII vintage. The ML6 was simply a version of the ML4 adapted for operation in sets powered by vehicle batteries.
ML6s were widely used as RF oscillators in medium-sizes military transmitters.
The wires attached to the top mica are a push fit into the shoulder of the envelope.
The carbonised anode, control grid and flat cathode.
The classic envelope is 44 mm in diameter and, excluding the B5 base pins, is 100 mm tall.
