The EBC81 is a double diode triode with the triode designed for audio amplification. The diodes share the same cathode as the triode.

Thanks to Michael for sending the photograph. Michael says that the EBC81 was used in his Normende Tannheuser stereo radio that dates from the 1960's. In this application the diodes were probably used as AM detector and AGC rectifier. A separate valve would be used for the FM demodulator.

The thin glass tube envelope is 55 mm in diameter, and excluding the B9A base pins is 22 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	a(t)	g1	k	h	h	a(d1)	s	a(d2)	ic

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	6.3	0.23	250	-3.0	1.0	58,000	1.2

Thanks to Frank Philipse for supplying the above PDF datasheet

 

This exhibit was last updated on 08 February 2009