The exhibit in the Collingwood Museum was labelled Pen4BA but we suspect that it is, in fact, a Mullard Pen4VA on a B7 base cap.

The classic envelope is 45 mm in diameter and, excluding the B7 base pins, is 113 mm tall.

References: ⁴⁰²⁴ & ¹⁰⁴³. Type Pen4VA was first introduced^¶ in 1933.

 
Pin Connections

B7	1	2	3	4	5	6	7
	-	g1	g2	h	h	k,h3	a

 
Absolute Maximum Operating Conditions^¶

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm	rk	rl	Pout	D
	4.0	1.35	250	250	-20	36	3.0	40,000	2.8	500	6,000	3.4W	10%

PDF scanned from an original document held by the museum

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