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 RCA logo and clearly marked - Made in USA.
The outer screen with mica holding the electrodes firm in the tubular envelope.
The wide glass tube envelope is 28 mm in diameter, and excluding the IO base pins is 72 mm tall.
References: Data-sheet, 3002 & 1040. Type 1N5GT was first introduced in 1937. See also1937 adverts.
