The X109 is a triode hexode mixer for operation at up to 100 MHz and designed for circuits with series heater chains.
The hexode is the lower section with the triode at the top. The strut in the foreground is the triode anode connection. The support with the getter holder at the top connects to the triode grid and the hexode g3. The triode anode is a simple square ended open U shape.
The closed end of the triode anode can be seen at the top.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 47 mm tall.
References: Data-sheet & 1040. Type X109 was first introduced in 1951. See also1951 adverts.