The 9AQ8 is a VHF double triode. These were used in Band III television tuners as RF amplifiers and oscillators.
The construction is of two pressed metal box anodes separated by space and an electrostatic screen. Within the small box anode cavity is a flat cathode and close spaced grid.
Face view of one triode with the screen behind.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall.
References: Data-sheet & 1040. Type 9AQ8 was first introduced in 1955. See also1955 adverts.