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 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.

 
Pin Connections

B8A	1	2	3	4	5	6	7	8
	h	a(2)	g1(2)	k(2)	a(1)	g1(1)	k(1)	h

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.6	250	-5.2	6.0	11,000	2.7

Thanks to Frank Philipse for supplying the above PDF datasheet

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This exhibit was last updated on 10 June 2007