The 35Z5GT is a half wave rectifier for heater chain service. The maximum reservoir capacitor is 40 μF and the surge limiting series resistance must be at least 100 Ohms.
The heater is tapped to allow a dial lamp to be wired in parallel with a portion of the heater. The lamp lasts longer as the surge is reduced and the radio continues to work with a broken dial lamp.
The remains of the word Radiotron can be seen on the base - an RCA brand.
The flat stitched anode. The heater tap goes to the L shaped support at the top of the valve.
The small front to back dimension and the heater tap support on the left.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 66 mm tall.
References: Data-sheet, 3002 & 1040. Type 35Z5GT was first introduced in 1939. See also1939 adverts.
