Sensibly equivalent¶ to:
The EH90 is an indirectly heated heptode frequency changer. Later, in the 1960's, Mullard application engineers designed circuits for the EH90 to act as an FM demodulator for 6 MHz inter-carrier sound of UK 625 line television.
See The Mullard EH90 for more information.
The side view of the anode shows the wire grids. The rods visible either side of the centre above the top mica are the g3 supports.
The thin glass tube envelope is 18 mm in diameter, and excluding the B7G base pins is 47 mm tall.
References: Datasheet & 1040. Type EH90 was first introduced in 1954.
Absolute Maximum Operating Conditions¶
Updated April 14, 2014. shape:thin.glass.tube construction:all.glass type:heptode age:1950.1960 base:b7g heater:6.3v pins:7 pin:1.g1 pin:2.k.g5 pin:3.h pin:4.h pin:5.a pin:6.g2.g4 pin:7.g3