The ECH11 is a triode hexode mixer, for superhet receivers, on a continental footless base. The Footless bas popular on the continent during WWII and used extensively by the German military. The naming convention and pin numbering matches the Mullard/Philips one. Mullard being the UK subsidiary, by then, of Philips of Eindhoven (Holland).
The wide metal tube envelope is 35 mm in diameter and, excluding the Footless base pins, is 35 mm tall.
References: Datasheet. Type ECH11 was first introduced in 1939.
Absolute Maximum Operating Conditions¶
Updated December29, 2012. shape:wide.metal.tube construction:glass.disc type:triode.hexode age:1930.1940 base:footless heater:6.3v pins:8 pin:1.g2.g4 pin:2.g1 pin:3.k.m pin:4.a pin:5.h pin:6.h pin:7.g3.g1(t) pin:8.a(t)