The 5687 is a special quality double triode. It is described as a general purpose medium gain triode pair with good emission. The pair can dissipate 7.5 Watts or a single triode can dissiapte 4.2 Watts.

The picture clearly shows the pair of flat cathodes at the top, with the copper grid supports either side of each cathode. The anodes are shaped and blackened.

The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 45 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	a(2)	g1(2)	k(2)	h	h	k(1)	g1(1)	hct	a(1)

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vg	mAa	ra	gm	μ
	6.3	0.9	300	-12.5	12.0	3,000	5.4	16

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 12 June 2007 {find valves by name}