The QQV03-10 is a Mullard design and follows the European pattern of a central common core and two spaced anodes finned for greater heat sinking. Here the exhibit is marked as Made in Holland - by the parent company Philips.
This valve type was much used for mobile VHF transmitters, as well as drivers for the larger power valves. such as the QQV06-40A.
In keeping with the Mullard practice the heater is centre tapped to enable operation from 12.6 volts as well as the normal 6.3V, thus making them directly suitable for operation from vehicle batteries.
A central column with common cathode, beam plates and screen grid plus single sided control grids. The anodes are rated for a dissipation of 5 Watts each.
The visible grid is the screen grid. It is shaped to give the required separation from the cathode and then passes flat across the centre of the valve. The control grids are very close to the cathode and not visible here. The control grids would be wound conventionally and then one side of the wires would be sheared off.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 69 mm tall.
References: Data-sheet & 1040. Type QQV03-10 was first introduced in 1955. See also1955 adverts.
