Sensibly equivalent¶ to:
The D77 is the Marconi equivalent of the Mullard EB91, and consists of two separate signal diodes in the envelope. The QD77 is a special quality version of this valve.
The diodes were designed for vision and sound detection in television receivers. Additionally they are recommended for limiting and DC restoration.
The MWT logo.
The thin glass tube envelope is 17 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
References: Datasheet & 1040. Type D77 was first introduced in 1949.
Absolute Maximum Operating Conditions¶
Updated January 05, 2013. 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)