The AC2/HL is an indirectly heated triode for mains broadcast receivers.

The identification lettering is etched into the dome of the envelope, as is the BVA logo.

The low power of the design can be deduced from the bright anode and the absence of grid cooling fins. The anode is formed into two U sections placed symmetrically either side of the cathode/grid assembly. The grid is wound under tension and can be seen to lie flat across the cathode and parallel to the anode plates.

When slightly tilted the construction of the anode is revealed. The grid construction is also more clearly seen.

The balloon envelope is 45 mm in diameter, and excluding the B5 base pins is 93 mm tall.

 
Pin Connections

B5	1	2	3	4	5
	a	g1	h	h	k

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	4.0	1.0	200	-1.75	4.9	15,000	5.0

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 05 July 2007 {find valves by name}