The TT24 VHF double beam tetrode follows the European pattern of a central common core and two spaced anodes finned for greater heat sinking.
The heater is centre tapped to enable operation from 12.6 Volts as well as the normal 6.3 V, thus making them directly suitable for operation from vehicle batteries.
The central common cathode with the screen grid visible. The central core is surrounded by the beam plates. The anodes are either side of the core.
The beam plates extend out beyond the anode plate. Each anode is made from two L shaped pieces stitched together to make a flat surface and a central flange.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 70 mm tall.