The EBC11 is a double diode triode. One diode is for detection of the amplitude modulated signal and the other diode is the rectifier diode used to generate the AGC voltage to control the IF amplifier and possible the RF amplifier also. The triode is the first audio amplifier stage.
We have the complete line-up of valves from the set this valve was used in. Frequency changer ECH11, IF amplifier EF11 x 2, demodulator, AGC detector and first audio stage EBC11, push-pull audio output EDD11 and rectifier EZ11.
The Identification is on the dome with the sides plain black paint. Note the copper evacuation tube that can be seen as the spigot has been broken off.
The wide metal tube envelope is 36 mm in diameter, and excluding the footless base pins is 42 mm tall.
Reference: Datasheet. Type EBC11 was first introduced in 1940.
Absolute Maximum Operating Conditions¶
Updated September 10, 2013. shape:wide.metal.tube construction:glass.disc type:double.diode.triode age:1930.1940 base:footless heater:6.3v pins:8 pin:1.a pin:2.g1 pin:3.k.m pin:4.- pin:5.h pin:6.h pin:7.a(d1) pin:8.a(d2)