Sensibly equivalent¶ to:
The VR56 is a pre-WWII UK RAF receiving pentode valve. The VR prefix in the type designation stands for Valve Receiving.
The valve in civilian name is an EF36 and this exhibit looks like a Mullard device from the size and shape of the envelope. Unlike VR56 this exhibit retains the full melallised paint screen coating.
This valve design was obsolete by the 1960s.
The reverse of the envelope carries the AM and crown logo of the UK Air Ministry.
The classic envelope is 30 mm in diameter and, excluding the IO base pins, is 85 mm tall.
References: Datasheet & 1040.
Absolute Maximum Operating Conditions¶
Updated October 21, 2016. shape:classic construction:pinch type:pentode age:1930.1940 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a pin:4.g2 pin:5.g3 pin:6.nc pin:7.h pin:8.k pin:tc.g1