Sensibly equivalent¶ to:
This Mullard EB91 double signal diode designed these for vision and sound detection is branded Bently by the reseller.
The EB91 dates from 1949 but the American 6AL5 was produced in 1946. Prior to the EB91 there was the EB41 all glass valve and the EB34.
The most common fault with the EB91 design is heater to cathode leakage.
The original Mullard lettering on this UK made valve.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
References: Datasheet 1040 & 3002. Type EB91 was first introduced in 1949.
Absolute Maximum Operating Conditions¶
Updated March 19, 2018. shape:thin.glass.tube construction:all.glass type:double.diode age:1940.1950 base:b7g heater:6.3v pins:7 pin:1.k(1) pin:2.a(2) pin:3.h pin:4.h pin:5.k(2) pin:6.s pin:7.a(1)