The 2A6 double diode triode is designed for detector and first audio stage in radio receivers made for the American domestic market. The heater voltage of 2.5V was the original (late 1920s) standard for American indirectly-heated AC mains valves.

The valve has a common cathode assembly, seen running vertically through the centre of the valve. The signal diode anodes are the bright plates seen in the centre of the envelope. Each side is insulated and forms a diode anode. The top of the electrode structure is the triode. The anode cavity is blackened.

The valve carries the ADZAM brand of RCA and also a paper band around the base showing that it was imported into France.

The classic envelope is 38 mm in diameter and, excluding the UX6 base pins, is 100 mm tall.

 
Pin Connections

UX6	1	2	3	4	5	6	tc
	h	a	a(d2)	a(d1)	k	h	g1

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	2.5	0.8	250	-1.35	0.4	91k	1.1

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 10 March 2008 {find valves by name}