The MSPen (1933) had the anode connected to the top cap. In the 'B' variant of 1937, the same device had the control grid connected to the top cap. The signal isolation afforded by taking the control grid to the top cap became standard practice for most manufacturers.

The amplifier pentode would have been used in RF and IF stages of domestic radio receivers.

The classic envelope is 42 mm in diameter and, excluding the B7 base pins, is 107 mm tall.

 
Pin Connections

B7	1	2	3	4	5	6	7	tc
	m	a	g3	h	h	k	g2	g1

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	4.0	1.0	200	100	-1.5	4.8	1.3	0.8M	2.8

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 02 December 2007