In the 1933 Mullard data book it is referenced as a general purpose valve for replacement use only and was sold for 13/6.
This exhibit has a plain glass envelope allowing the construction to be seen.
The pinch with mesh anode above. The top heater support is in the centre of the image.
The construction uses the old method of fixing the top electrode supports within a glass rod. This was the preferred method during the Azide days when the Barium decomposition splattered the inside of the glass and many of the other components.
Side view of the electrodes. The getter holder is bottom right.
In this enhanced image the form of the anode mesh is clear and the grid winding can be seen.
Looking into the dome the oxide coated cathode can be seen and the grid has been formed into a small central section by squeezing the wider parts of the winding.
The balloon envelope is 46 mm in diameter, and excluding the B5 base pins is 92 mm tall.
References: Data-sheet, 4023 & 1043. Type 244V was first introduced in 1930. See also1930 adverts.
