The 1LD5 is a single diode pentode for operation from dry batteries. It probably dates from the 1940s and was employed in broadcast radio receivers.

The wide glass tube envelope is 28 mm in diameter and, excluding the B8B base pins, is 55 mm tall.

 
Pin Connections

B8B	1	2	3	4	5	6	7	8
	f+	a	g2	a(d)	-	g1	-	f-

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	1.4	0.05	90	45	-0	0.6	0,1	0.95M	0.6

Thanks to Frank Philipse for supplying the above datasheet

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