The 6U5 is a Magic Eye tuning indicator and this example was made by Hytron. The triode amplifier electrode assembly is mounted centrally in the envelope with the display above.
The triode section seen along the grid axis.
The triode section seen full face. Note the anode connected to a flat extension that passes into the display bowl.
The display bowl.
The wide glass tube envelope is 29 mm in diameter and, excluding the UX6 base pins, is 87 mm tall.
References: Data-sheet, 1043 & 1040. Type 6U5 was first introduced in 1937. See also1937 adverts.
