The 20L1 from Mazda is from the early days of all glass construction in the UK. This is a low impedance amplifier double triode and could have found uses in a wide variety of equipment. The 12.6 Volt heater requirement makes this particularly suitable for vehicle use. The 6L1 is identical except for a 6.3 Volt heater.

The thin glass tube envelope is 19 mm in diameter and, excluding the B8A base pins, is 53 mm tall.

 
Pin Connections

B8A	1	2	3	4	5	6	7	8
	h	a(2)	g1(2)	k(2)	a(1)	g1(1)	k(1)	h

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	12.6	0.2	250	-11.5	10.0	6,200	2.8

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 04 June 2007 {find valves by name}