The UAF41 is an early all glass valve and consists of a single diode and a variable μ RF amplifier pentode in a single envelope.

The valve is screened and the envelope has the moulded glass pip for pin registration in the metal skirt of the base. The first B8A valves had metal skirts fitted with built in locating pips and spigots to guide the valve into its base.

Mullard do not list this valve in 1949, so we think it dates from the early 1950s.

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	a(d)	g3	g2	g1	k,s	h

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	12.6	0.1	200	85	-2.0	5.0	1.5	1.0M	2.0

Thanks to Frank Philipse for supplying the above datasheet

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