The EF42 miniature high slope RF pentode is of an all glass construction and dates from 1950. Mullard specify this device for use as an RF or an IF amplifier.

The pins are equi-spaced and the external metal skirt has a locating pip, seen on the right in the picture.

The thin glass tube envelope is 20 mm in diameter and, excluding the B8A base pins, is 52 mm tall.

 
Pin Connections

B8A	1	2	3	4	5	6	7	8
	h	a	s	g3	g2	g1	k	h

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	6.3	0.33	250	250	-2	10	2.3	0.44M	9.5

Thanks to Frank Philipse for supplying the above datasheet

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