The 9D7 is a variable μ pentode. Brimar do not give a designated frequency range in their literature. As variable μ pentodes are used in AGC amplification systems, this suggests a role in IF amplification at up to 10.7 MHz.

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	g1	k	h	h	s	a	g2	g3

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	mAa	gm
	6.3	0.3	250	100	10	8.4

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 05 July 2007 {find valves by name}