The EBF2 is a double diode triode. This exhibit is labelled Philips and is exactly the same dimensions as the Mullard sample that we have. The Ct8 base was popular on the Continent but never caught on in the UK. We suspect that both valves were made by Philips. 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.

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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