This military valve is electrically equivalent to an 807. It could therefore be used at audio or for RF power generation up to 30 MHz.
Ceramic is less leaky at RF in damp conditions and the ceramic based versions would have been used in tropical and aircraft applications.
The valve employs a oxide coated cathode, wire inner grids and bright beam forming plates within a carbonised oval anode cylinder. The elliptical lower screen is a characteristic of this design.
A general view of the electrodes.
Looking along the seam of the anode, the centre of heat production, the wire grids and bright beam plate can be seen beyond the top and bottom of the anode.
The top screening box shields the tops of the grids from the anode connection. The strut bridging the two sides of the anode connects to the top cap. In this exhibit the top cap itself has been lost but the vacuum is not impaired.
The open side of the top screen reveals the tops of the grids. The gap between the top mica and the anode allows a view of the internal structure.
The ceramic base cap and UX5 base pins.
The classic envelope is 50 mm in diameter, and excluding the UX5 base pins is 119 mm tall.
