The DH77 amplifier triode with twin signal diodes on a common cathode. It was designed for use in superhet receivers at the end of the IF chain and as the first audio amplifier feeding the output stage.

The thin glass tube envelope is 17 mm in diameter and, excluding the B7G base pins, is 46 mm tall.

 
Pin Connections

B7G	1	2	3	4	5	6	7
	g1	k	h	h	a(d2)	a(d1)	a

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.3	250	-3	1.0	58,000	1.2

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 06 July 2007 {find valves by name}