The ECF80 was originally a British made product as in ECF80 but this later example was made abroad when it became cheaper to manufacture overseas.The ECF80 was designed for operation up to 220 MHz. As 1950s television receivers tended to use the PCFnn 300 mA valves, the production of this valve with a 6.3 Volt heater suggests that it was aimed at the professional VHF communications market.
The triode on the right with the screen between it and the pentode. The bars above the base connect the two heaters in parallel. The heater wire can be seen to be coiled, insulated and bent into a hairpin for passing into the cathode.
The holes in the pentode anode reveal the wire grids.
A closer view of the triode.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 53 mm tall.
References: Data-sheet & 1040 Type ECF80 was first introduced in 1954.