The 6GW8 was one of the last audio triode output pentode valves designed. Uses were in domestic radio and audio equipment. Normally in single ended output stages for radiograms and tape recorders. The design proved popular in low cost stereo systems and was made by several companies, this exhibit being labeled Sylvania but made in England, probably by Mullard.

The triode is on the left. At the right can be seen the top of the control grid support rods complete with radiator fins. The getter holder is at the extreme right.

The pentode with the triode in the top left corner. The ratings for the triode section are almost identical to one half of the ECC83.

The thin glass tube envelope is 21 mm in diameter and, excluding the B9A base pins, is 70 mm tall.

 
Pin Connections

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

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.7	250	-1.9	1.2	62k	1.6

Pentode	Va	Vs	Vg	mAa	mAs	ra	gm	Pout	D
	250	250	-7	36	6	48k	10	4W	10%

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 04 July 2009