The VP13A is a variable μ amplifier pentode, and features the Ct8 side contact base.
In use the variable μ pentode was designed for AGC controlled stages of superhet receivers, the RF and IF sections. The control grid is taken to the top cap for maximum isolation between grid and anode circuits.
The plain screening paint on the reverse.
The base cap with the side contact base strips.
The classic envelope is 42 mm in diameter, and excluding the Ct8 base pins, is 98 mm tall.
References: Data-sheet & 1043. Type VP13A was first introduced in 1934. See also1934 adverts.
