Sensibly equivalent¶ to:
The EBC33 is a double diode triode with a common cathode. The design dates from the late 1930s (1937-1940). This is another case of a valve that was released with the continental Ct8 base as well as the IO base. See EBC3 for the Ct8 version. Both had identical electrical characteristics.
Typically such multiple valves would be used in superhet receivers at the end of the IF amplification chain. One diode would produce the AGC voltage and the other would be used as the AM signal demodulator feeding into the triode as a first audio amplifier.
Our other EBC33 shows different markings and points to a long life for the design or production in different factories or a change of marketing.
The classic envelope is 29 mm in diameter and, excluding the IO base pins, is 85 mm tall.
References: Datasheet, 1040, 1043 & 3002. Type EBC33 was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated February 16, 2013. shape:classic construction:pinch type:double.diode.triode age:1930.1940 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a pin:4.a(d2) pin:5.a(d1) pin:6.- pin:7.h pin:8.k pin:tc.g1