The AC2/HL screened triode was introduced by Mazda in 1931.

As the metalising has fallen off in places it has been possible to photograph the internal structure. Apart from the clearly visible indirectly heated flat cathode, the fine control grid is just seen. The glass pinch is labelled AC2/HLJ.

The metalised balloon envelope is 43 mm in diameter and, excluding the B5 base pins, is 90 mm tall.

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	4.0	1.0	250	-1.2	2.5	11,500	6.5

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 02 December 2007 {find valves by name}