The UABC80 is a triple diode triode in a miniature envelope.

It can be seen in the photograph that three separate valves exist within the envelope. The triode is at one end, the single diode at the other end. In the middle is the double diode, with each half of the box anode insulated from the other.

The UABC80 and its 300 mA brother PABC80 were specifically designed for use in the detector stage of early FM and FM/AM radios. Normally this valve featured in a ratio detector circuit for FM demodulation and a diode detector for AM as well as the first stage of audio amplification.

See also aaa0405.

The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins, is 58 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	a(d3)	a(d2)	k(d2)	h	h	a(d1)	k,k(d1),k(d3)	g1	a

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	ra	gm
	28	0.1	200	-2.3	1	50k	1.4

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 03 July 2009