The 35Z4GT is a half wave rectifier and was designed for equipment where low heater power was important. Halicrafters made communications receivers not valves.
The 35Z4 would feed a 40 µF reservoir capacitor through an effective series resistance of 100 Ohms.
As a half wave rectifier, only a single section is required. The cathode is a small tube and the spread of the anode into side wings is for mounting and heat dissipation.
In close-up the method of holding both sides of the anode together becomes clear. The exposed fixing lugs are bright as the blackening of the anode plate is on the outer surface of each plate only. The cathode connection can be seen on the left as can the heater wires entering the cathode.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 68 mm tall.
