The type 226 is also known as type 26 and in this case as NX-226.
The 226 is an AC filament valve used for radio applications such as RF and IF where the mains hum was not important. It was not to be used where AF was present such as the detector or audio stages.
The bright box anode with the grid winding visible at the base.
The solid UX4 base pins.
Thanks to Mark Mallison for sending the images.
The balloon envelope is 44 mm in diameter, and excluding the UX4 base pins is 95 mm tall.
Reference: Data-sheet. Type 226 was first introduced in 1927. See also1927 adverts.
