This DAC32 is considerably shorter than other Mullard versions. The height matches the Sylvania version but this is a British Made valve and not an import.
The DAC32 is a dry battery diode triode that was designed, after WWII, for AM broadcast radio reception. Mullard describe this valve as a medium gain triode for use as an AF voltage amplifier combined with a single diode for signal or AVC (AGC) rectification.
The filament power is very low and consequently the valve is rated for a very low current.
The triode is at the top and above the base is a screening box that contains the single diode anode rod - left of centre.
Side view with the top filament support to the left with tension spring at the top.
The filament is a single coated strand of wire. The grid extends above and below the anode and connection is made to the top cap.
The wide glass tube envelope is 29 mm in diameter and excluding the IO base pins it is 70 mm tall.