Sensibly equivalent¶ to:
The 5840 is the special quality version of the EF732 pentode. It appears to be an updated version of the EF72.
The 5840 was designed for wide band HF amplification under adverse conditions where good reliability is required. These applications include military equipment and industrial applications. As it will maintain its emission when used with long periods operating at cut-off, application in computer circuits are a possible use.
Another application area is as a microphone pre-amplifier built into condenser microphones.
The thin glass tube envelope is 9 mm in diameter and, excluding the B8D base pins, is 36 mm tall.
References: Datasheet & 3002. Type 5840 was first introduced in 1957.
Absolute Maximum Operating Conditions¶
Updated January 31, 2013. shape:thin.glass.tube construction:all.glass type:pentode age:1950.1960 base:b8d heater:6.3v pins:8 pin:1.g1 pin:2.k.g3 pin:3.h pin:4.k.g3 pin:5.a pin:6.h pin:7.g2 pin:8.k.g3