The 6F15 is an early all glass variable μ pentode. It would have been designed for AGC controlled RF and IF amplifiers.
The mutual conductance is a function of the winding pitch of the control grid. In variable μ types the grid would be wound with a graded pitch from fine to course.
The base skirt with central locating spigot. The locating pip is on the side of the metal skirt.
The thin glass tube envelope is 20 mm in diameter and, excluding the B8A base pins, is 54 mm tall.
References: Datasheet & 1040. Type 6F15 was first introduced in 1948.
Absolute Maximum Operating Conditions¶
PDF scanned from an original document held by the museum
Updated January 12, 2016. shape:thin.glass.tube construction:all.glass type:pentode age:1940.1950 base:b8a heater:6.3v pins:8 pin:1.h pin:2.a pin:3.s pin:4.g3 pin:5.g2 pin:6.g1 pin:7.k pin:8.h