The 9D2 is a variable μ Rf pentode. The 200 mA heater requirement indicates that this valve is suitable for series heater chain use.

The base has the Brimar logo heat pressed into it.

Inside the outer cylindrical screen is the anode cylinder, three wire grids and an oxide coated cathode in the centre.

The classic envelope is 38 mm in diameter, and excluding the B7 base pins is 96 mm tall.

 
Pin Connections

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

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm	μ
	13	0.2	250	125	-1	10.0	3.5	0.6M	1.65	1,000

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 09 March 2008 {find valves by name}