This glass version of the MS4B is probably contemporary (1933-4) with the Catkin version MS4B. It is certainly neither very early nor particularly late.

The missing top cap connector was almost certainly of the black screw-on type.

It is a tetrode from the early mains valve era with its 4 Volt heater. The screened tetrodes and pentodes were employed for RF and IF amplification.

The balloon envelope is 43 mm in diameter and, excluding the B5 base pins, is 110 mm tall.

 
Pin Connections

B5	1	2	3	4	5	tc
	g2	g1	h	h	k	a

 
Absolute Maximum Operating Conditions

Tetrode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	4.0	1.0	200	80	-1	3.4	1.2	0.35M	3.2

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 03 June 2007 {find valves by name}