The UBF11 is a double diode pentode with a 100 mA heater. This suggests use in domestic radio receivers for use on both AC and DC mains supplies. The double diode in the envelope points to signal demodulation and AGC voltage rectification in a superhet receiver.

The metal tube construction commenced in Germany in 1938 and was originally introduced by RCA in the USA in 1935.

The wide metal tube envelope is 35 mm in diameter and, excluding the Footless base pins, is 35 mm tall.

 
Pin Connections

Footless	1	2	3	4	5	6	7	8
	g2	g1	k,g3,m	a	h	h	d(1)	d(2)

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs
	20	0.1	200	200	-	5.0	1.7

Thanks to Frank Philipse for supplying the above PDF datasheet

 

This exhibit was last updated on 01 February 2008