The 1L4 is a miniature voltage amplifier pentode with low filament current consumption. The Mullard equivalent from its 1950s range is DF92. It would be used for portable domestic radio equipment.

The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 44 mm tall.

 
Pin Connections

B7G	1	2	3	4	5	6	7
	f-	a	g2	-	f-	g1	f+

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	1.4	0.05	90	67.5	0	3.7	1.4	0.5M	1.0

Thanks to Frank Philipse for supplying the above datasheet

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