Triode+Beam-Output-Tetrode. With only 12% space volume, 70% heater power and 4 to 3.8 watts output power against the ECL11, the ECL86 represents the final perfection of this kind of tubes. Those AF-multiple-tubes were asked for again, as FM-detectors became fitted with Ge-diodes, making the EABC80 obsolete.