The 11E13 is the STC implementation of the transmitting double beam tetrode more commonly known as the QQV03-10.
The design follows the European pattern of a central common core and two spaced anodes finned for greater heat sinking. This valve type was much used for mobile VHF transmitters, as well as drivers for the larger power valves. such as the QQV06-40A.
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 discoloured lettering shows that these valves ran very hot in use, especially for CW of FM transmitters where full carrier power was required during the entire transmitting period.
The anodes are at the sides with the central column surrounded by the common beam plate. Within the beam plate the single screen grid can be seen. The single sided control grids are just visible.
The screen grid passes flat across the cathode. Even in this image the control grids are not clearly seen.
The CV2798 indicates direct equivalence with the commercial Type.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 64 mm tall.