This EZ81 clearly shows the method of construction of the two anodes around the central cathode.
The EZ81 was introduced by Mullard as a high current B9A rectifier, the lower power rectifier was the pin compatible 90 mA EZ80.
In use the maximum reservoir capacitor would be limited to 50 µF and to prevent damage by excess current an effective series resistance of 230 Ω is required.
On this Pinnacle exhibit two Type designation are printed on the envelope with U709 appearing alongside the EZ81.
The two anodes are mounted at right angles to one another and appear to have a smaller surface radiating area than the smaller EZ80.
Side view of the top anode and face view of the lower anode. The heater is coiled and probably made from tungsten. The copper support looks to have melted around the heater wire.
The thin glass tube envelope is 22 mm in diameter and, excluding the B9A base pins, is 70 mm tall.
References: Data-sheet, 3002 & 1040. Type EZ81 was first introduced in 1954. See also1954 adverts.
