The EC91 is a miniature single triode. The Mullard manual describes the EC91 as a miniature screened triode for use as a grounded grid amplifier.

Mullard also produced the M8099 special quality version for critical applications.

This type of valve was designed for RF applications at VHF up to a maximum frequency of 250 MHz. These would include radio, television and radar. The equivalent noise resistance was given as 400 Ohms.

The thin glass tube envelope is 17 mm in diameter and, excluding the B7G base pins, is 45 mm tall.

 
Pin Connections

B7G	1	2	3	4	5	6	7
	g	k	h	h	k	g	a

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.3	250	-1.5	10	12k	8.5

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 10 June 2007 {find valves by name}