The 6SN7GT is a small glass tubular audio double triode, the design dates to the 1940's. This was a classic valve with two separate triodes in the one envelope. The 6SN7 remains the most popular Octal based double triode valve for audio applications. The valve is especially well suited to phase splitter designs.

We have many exhibits from the 6SN7 family in different envelope sizes and with different construction methods. This device uses a miniature pinch as does the Radiotron 6SN7GT

The wide glass tube envelope is 27 mm in diameter and, excluding the IO base pins, is 65 mm tall.

References: Datasheet, ¹⁰⁴⁰ & ¹⁰⁴³. Type 6SN7GT was first introduced^¶ in 1941.

 
Pin Connections

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

 
Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.6	250	-8	9.0	7700	2.6

Thanks to Frank Philipse for supplying the above PDF datasheet

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