The 12SJ7 is an amplifier pentode and is the 12.6 Volt heater version of the 6SJ7. It is an American metal valve, that were developed in the mid 1930s, and was probably used as an IF amplifier.

The thin metal tube envelope is 24 mm in diameter and, excluding the IO base pins, is 50 mm tall.

 
Pin Connections

IO	1	2	3	4	5	6	7	8
	m	h	g3	g1	k	g2	h	a

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	12.6	0.15	250	100	-3	3	0.8	1M	1.65

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 12 June 2007 {find valves by name}