The DL35 is an octal based audio output beam tetrode for use with dry batteries. This is no miniature valve so the probability is that the broadcast receivers that it was to be used with were large static pieces of equipment.

The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 71 mm tall.

References: Datasheet, ¹⁰⁴⁰ & ¹⁰⁴³. Type DL35 was first introduced^¶ in 1946.

 
Pin Connections

IO	1	2	3	4	5	6	7	8
	-	f+	a	g2	g1	-	f-	-

 
Absolute Maximum Operating Conditions^¶

Beam Tetrode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm	Pout	D
	1.4	0.1	90	90	-7.5	7.5	1.6	110k	1.55	0.24W	10%

Thanks to Frank Philipse for supplying the above PDF datasheet

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