The 6AM4 UHF triode is designed for grounded grid operation to ensure the maximum isolation between input and output circuits. The grid has many connections in order to approximate to a ring.

The gold-plated pins indicate that this is a relatively modern specimen (1980s? and suggest professional usage in communications link equipment eg. on a microwave link tower. This is not your average TV valve!

The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 37 mm tall.

 
Pin Connections

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

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	gm
	6.3	0.225	200	-1	10	9.8

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 02 July 2007 {find valves by name}