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.
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.
This example carries both the final version of the Mullard valve logo and it was made in the USA.
In the centre of the working face of the anodes is the side flange for extra radiating area.
The anodes are top and bottom, the beam plate is bright and common to both sections as is the screen grid. The latter wires pass flat across the cathode. Just visible are the single sided control grids.
The copper support of the lower control grid can be seen as can the screen grid support closed over the wire strands.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 70 mm tall.
References: Data-sheet & 1040. Type QQV03-10 was first introduced in 1955.