The 6K8GT was purpose designed for radio as a mixer or frequency changer. The valve has a common cathode and the triode and hexode control grids are internally connected.

The local oscillator would produce 7.5 Volts peak to peak signal from the triode section.

The input signal would be coupled to the frequency changer via the top cap connection to grid 3.

The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 71 mm tall.

 
Pin Connections

IO	1	2	3	4	5	6	7	8	tc
	m	h	a	g2-g4	g(t)-g1	a(t)	h	k	g3

 
Absolute Maximum Operating Conditions

Hexode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	6.3	0.3	250	100	-3	2.5	6	0.6M	0.36

Triode	Va	mAa
	100	3.8

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 04 July 2007 {find valves by name}