The 1N5GT is a variable μ RF pentode for dry battery operation. The design is American and the VT-146 designation shows that it was a design supplied to the US military. The 1N5GT is used at both RF and IF in superhet receivers.
Etched into the envelope is the octagonal border and the Type designation 1N5 with GT below. The border can be seen as a feint image on the right of the main picture.
The solid outer screen. Other examples have a perforated screen. The Type designation is on the left.
The Type designation etched into the glass. This image is significantly enhanced.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 69 mm tall.
References: Data-sheet, 3002 & 1040. Type 1N5GT was first introduced in 1937. See also1937 adverts.
