The W143 is a variable μ amplifier pentode. It is equivalent to the Mullard EF22 and our EF22 exhibit looks very much like this valve, to the point where they probably came off the same Philips production line.

The Made in Holland suggests Philips.

The wide glass tube envelope is 27 mm in diameter, and excluding the B8B base pins is 61 mm tall.

 
Pin Connections

B8D	1	2	3	4	5	6	7	8
	g3	s	g2	g1	a	k	h	h

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	6.3	0.2	250	100	-2.5	6	1.7	1.2M	2.0

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 31 August 2008 {find valves by name}