The 6B8 American metal valve is a double diode pentode. Such valves were made for the signal detector, AGC detector and first audio amplifier stages of superhet receivers.

The thin metal tube envelope is 24 mm in diameter and, excluding the IO base pins, is 62 mm tall.

 
Pin Connections

IO	1	2	3	4	5	6	7	8	tc
	m	h	a	a(d2)	a(d1)	g2	h	k	g1

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	6.3	0.3	250	125	-3	10	2.3	0.6M	1.33

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 09 June 2007 {find valves by name}