The 6DS8 is a triode heptode frequency changer has the unusually low anode voltage of 12.6 Volts, the voltage of vehicle batteries. This valve was clearly designed for use in such an environment and was intended for use as a mixer in hybrid car radios. In such designs the front end would be valve based and the audio section would be transistor. Early transistors not being particularly good at RF.

On the left can be seen the Copper control grid support rods and the spiral wound heater in its insulated coating. Through the hole in the shield can be seen the grid support but little else.

See also ECH83, EBF83, ECC86 and EF98.

The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins the valve is 59 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	g2,g4	g1	k,g5,s	h	h	a	g3	a(t)	g1(t)

 
Absolute Maximum Operating Conditions

Heptode	Vh	Ah	Va	Vs	mAa	mAs	ra	gm
	6.3	0.3	12.6	12.6	0.15	0.35	1.5M	0.2

Triode	Va	mAa
	12.6	0.75

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 04 July 2009