The 30C17 is a triode variable-mu pentode designed for frequency changer use. The variable-mu pentode enables the AGC line to be applied to the mixer and avoid overloading on strong local signals. The intended frequency range was probably VHF.

The perforated cylindrical screen encloses the pentode but not the triode. Both cathodes are connected together internally.

The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 47 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	k	g2	a	h	h	a(t)	g1(t)	k,s,g3	g1

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	7.4	0.3	155	135	-3.0	7.8	2.4	0.4M	4.7

Triode	Va	mAa
	60	7.0

Thanks to Frank Philipse for supplying the above datasheet

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