Sensibly equivalent¶ to:
The ECC40 from Mullard dates back to the early days of all glass construction. This valve is two independent triodes within the single envelope and with a gain of 30 would be useful for most purposes including instrumentation. Mullard describe the ECC40 as a low-microphony double triode with separate cathodes, primarily intended for use as an AF voltage amplifier or phase splitter. The 6SN7GT was the valve it was designed to replace and three years later it was superseded by the ECC82 on the B9A base.
The foot containing the pins is joined to the envelope with a groove that is characteristic of Philips production. This suggests either an import of the valve or an import of a Philips designed assembly line.
The thin glass tube envelope is 20 mm in diameter and, excluding the B8A base pins, is 60 mm tall.
References: Datasheet, 3002 & 1040. Type ECC40 was first introduced in 1948.
Absolute Maximum Operating Conditions¶
Updated January 31, 2013. shape:thin.glass.tube construction:all.glass type:double.triode age:1940.1950 base:b8a heater:6.3v pins:8 pin:1.h pin:2.a(2) pin:3.g1(2) pin:4.k(2) pin:5.a(1) pin:6.g1(1) pin:7.k(1) pin:8.h