Sensibly equivalent¶ to:
The 6K7 pentode was designed for intermediate frequency amplifiers in 'modern' superhet type receivers during the mid 1930s. A couple of years later the slightly changed single ended version 6SK7 appeared.
It is high impedance allowing for a high Q in the tuned anode circuit. It has a long grid base allowing for the stage gain to be altered according to the grid bias applied. Thus this a variable-μ valve where the gain is to be controlled by and AGC voltage developed at the detector stage. This was usually an additional diode. Typically within a double diode triode such as the 6Q7.
See also 6K7G for the glass envelope version.
The thin metal envelope is 25 mm in diameter and, excluding the IO base pins, is 60 mm tall.
References: Datasheet & 1040. Type 6K7 was first introduced in 1936.
Absolute Maximum Operating Conditions¶
Updated November 16, 2013. shape:thin.metal.tube construction:glass.disc type:pentode age:1930.1940 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a pin:4.g2 pin:5.g3 pin:6.nc pin:7.h pin:8.k