Sensibly equivalent¶ to:
10LD12 28AK8 DH109
The UABC80 is a triple diode triode in a miniature envelope and this exhibit was made by Mullard in France. We also have a British made UABC80 with yellow lettering from the Mullard Golden Jubilee year in 1969.
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. for more details see UABC80.
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.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins, is 58 mm tall.
References: Datasheet, 3002 & 1040. Type UABC80 was first introduced in 1952.
Absolute Maximum Operating Conditions¶
Updated January 29, 2016. shape:thin.glass.tube construction:all.glass type:triple.diode.triode age:1950.1960 base:b9a heater:100ma pins:9 pin:1.a(d3) pin:2.a(d2) pin:3.k(d2) pin:4.h pin:5.h pin:6.a(d1) pin:7.k.k(d1).k(d3) pin:8.g1 pin:9.a