The HABC80 is a triple diode triode. The triode and two diodes share a common cathode but one diode has a separate cathode.
Electrically the HABC80 is identical to the EABC80 except for the heater rating. The H prefix denotes a 150 mA heater designed for heater chain use. This implies good heater cathode insulation. The xABC80 series was specifically designed for use in the detector stage of early FM and FM/AM radios. The triode section providing the first audio amplification, the single diode and one of the diode pair were used as an FM detector in a ratio detector circuit. SeeFM Broadcasting and Signal Detection. The other diode in the pair being used as the AM detector when that part of the circuit was required.
The xABC80 family includes UABC80 100 mA heater, PABC80 300 mA heater as well as the EABC80 with a 6.3 Volt heater.
The valve was made by Brimar but the reseller in this case was a London Company Technical Trading. I believe they were in a side street off the Charing Cross Road until the 1970s.
The three towers, two are shields for the diode anodes and the third (on the left) is the triode.
The thin glass tube envelope is 21 mm in diameter and, excluding the B9A base pins, is 60 mm tall.
References: Data-sheet, 1040 & 3002. Type HABC80 was first introduced in 1953. See also1953 adverts.