This ECC85 shows another version of this definitive double triode for the front end stages of FM radio receivers. This valve shows the Telefunken livery.

The two independent valves are screened by a rectangular plate across the diameter of the envelope. One triode would be used as an RF amplifier and the other as the local oscillator. The oscillator would be run 10.7 MHz lower than the incoming signal, and in the mixer a standard 10.7 MHz IF would be produced.

The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 46 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	a(2)	g(2)	k(2)	h	h	a(1)	g(1)	k(1)	s

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.435	250	-2.3	10	9700	5.9

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 06 July 2007 {find valves by name}