The SP13 screened amplifier pentode was introduced in 1934-5. This version has the Ct8 base and the similar SP13C has a B7 base. The use would have been for HF amplification in radio receivers. It is a non variable-mu valve and was displaced in favour of the variable μ pentode when TRF receivers gave way to mass produced superhet receivers.

The classic envelope is 40 mm in diameter, and excluding the Ct8 base pins, is 104 mm tall.

 
Pin Connections

Ct8	1	2	3	4	5	6	7	8	tc
	m	h	h	k	g3	-	g2	a	g1

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	ra	gm
	13.0	0.2	200	100	-	3	1.3M	2.2

This exhibit was last updated on 21 July 2005