The EF86 is the standard early stage audio pre-amplifier valve. This exhibit is branded with the name of a well known dealer, originally based in London and latterly in West Sussex. The actual manufacturer is not known.

The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins, is 47 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	g2	s	k	h	h	a	s	g3	g1

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.2	250	-5	4	16k	2

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 11 July 2007 {find valves by name}