The EBF2 is a delightful double diode triode with the Mullard bright red metalising and our exhibit is unused. The valve is a high impedance variable μ pentode, with two auxiliary diodes all sharing a common cathode. This valve would have been used in radio receivers probably with the triode as an AGC amplifier. This would imply communications receivers as broadcast sets would use a straight triode for the audio voltage amplifier.

The classic envelope is 29 mm in diameter and, excluding the Ct8 base pins, is 85 mm tall.

References: Datasheet & ¹⁰⁴³. Type EBF2 was first introduced^¶ in 1938.

 
Pin Connections

Ct8	1	2	3	4	5	6	7	8	tc
	m	h	h	k	a(d1)	a(d2)	g2	a	g1

 
Absolute Maximum Operating Conditions^¶

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	6.3	0.2	250	250	-2	5	2	2M	1.8

Thanks to Frank Philipse for supplying the above PDF datasheet

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