The DF11 is a directly heated battery pentode for use at HF and IF in radio receivers.
The makers name and logo together with the Type designation.
The wide metal tube envelope is 36 mm in diameter, and excluding the footless base pins is 44 mm tall.
References: Datasheet, 1040 & 1043. Type DF11 was first introduced in 1940.
Absolute Maximum Operating Conditions¶
Updated November 27, 2014. shape:wide.metal.tube construction:glass.disc type:pentode age:1930.1940 base:footless pins:8 pin:1.g2 pin:2.g1 pin:3.f(-).m.g3 pin:4.- pin:5.f(+) pin:6.f(-) pin:7.- pin:8.a