The VR65 is a WWII military receiving pentode valve made for the RAF. The VR in the designation provides this information. Commercially this is an SP61 that was developed originally for television RF stages. The SP41 is the same electrically but has the pre-war 4.0 Volt standard heater.
With the grid at the top cap, this is the normal pattern for RF and IF amplifier valves of the period. Providing high gain in tuned anode circuit applications. For additional screening the valve is covered with an external metallisation.
The VR65 was used in air-borne radar particularly GEE.
The reverse is plain.
The VR65 was supplied in this box that describes the change of Type designation to the CV reference.
The classic envelope is 32 mm in diameter and, excluding the MO base pins, is 88 mm tall.
References: Data-sheet & 1043. Type VR65 was first introduced in 1941. See also1941 adverts.
