The EK3 octode frequency changer is set on the short lived side contact base. Our other EK3 has an envelope of reduced diameter and the paint damage clearly shows the effects of excessive heating.

The local oscillator formed using a grid as anode would need to supply 17 volts peak to adequately modulate the main electron flow. The signal input to g4 is applied to the top cap for maximum circuit isolation. The frequency of use would be a few megahertz at best.

The metallising paint has a reticulated surface. The black paint for the identification lettering adheres well.

The classic envelope is 56 mm in diameter and, excluding the Ct8 base pins, is 115 mm tall.

 
Pin Connections

Ct8	1	2	3	4	5	6	7	8	tc
	m	h	h	k	g2	g1	g3,g5	a	g4

 
Absolute Maximum Operating Conditions

Octode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	6.3	0.65	250	100	-2.5	2.5	5.5	2M	0.65

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 10 June 2007 {find valves by name}