The Mullard ECC81 was designed for RF use and is of the low impedance type.

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

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	a(2)	g1(2)	k(2)	h	h	a(1)	g1(1)	k(1)	hct

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.6	250	2.0	10.0	10,000	5.5

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 10 June 2007 {find valves by name}