Sensibly equivalent¶ to:
The VR56 is a pre-WWII military receiving pentode valve. The VR prefix in the type designation stands for Valve Receiving and was specified for the UK Air Force. This exhibit was made in Canada by Rogers and also has the old stores code of 10E/11402 printed on the screening paint.
The valve in civilian name is an EF36. This valve was obsolete by the 1960s, and our data sheets show that the EF36 had identical characteristics and pin connections to the EF37 and EF37A. These were all high gain low current intermediate frequency amplifiers in superhet receivers and all featured external metallisation. With their low capacitances they would be useful at radio frequencies as well as IF.
The up arrow was used by the Air Ministry and the C around the arrow on the glass probably indicates a product from Canada.
The wide glass tube envelope is 30 mm in diameter and, excluding the IO base pins, is 83 mm tall.
References: Data-sheet & 1040.
Absolute Maximum Operating Conditions¶
Updated April 22, 2021.