The 6AQ5 ia a small audio output beam tetrode valve capable of 4.5 Watts in a single ended configuration.

The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 58 mm tall.

References: Datasheet & ¹⁰⁴⁰. Type 6AQ5 was first introduced^¶ in 1950.

 
Pin Connections

B7G	1	2	3	4	5	6	7
	g1	k,bp	h	h	a	g2	g1

 
Absolute Maximum Operating Conditions^¶

Beam Tetrode	Vh	Ah	Va	Vs	Vg	mAa	gm	Pout
	6.3	0.45	250	250	-12.5	45	4.1	4.5W

Thanks to Frank Philipse for supplying the above PDF datasheet

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