Sensibly equivalent¶ to:
The EH90 is an indirectly heated heptode frequency converter. It was also used in the 1960's as an FM demodulator for 6 MHz inter-carrier TV sound.
See EH90 for full details.
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: Data-sheet & 1040. Type EH90 was first introduced in 1954.
Absolute Maximum Operating Conditions¶
Updated February 07, 2019. 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