Sensibly equivalent¶ to:
CV918 KTW74M W76
The 12K7GT variable-mu screened pentode was designed in the 1940's for intermediate frequency amplifiers in superhet receivers where the stage gain was controlled by the application of negative bias on the grid. That bias or AGC voltage was derived from the received signal by rectification. It is high impedance valve allowing for a high Q in the tuned anode circuit.
See also 6K7.
The wide glass tube envelope is 28 mm in diameter and, excluding the IO base pins, is 67 mm tall.
References: Data-sheet, 1040 & 1043.
Absolute Maximum Operating Conditions¶
Updated November 18, 2013. shape:wide.glass.tube construction:pinch type:pentode age:1940.1950 base:io heater:12.6v 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 pin:tc.g1