The 5R4WGB is a directly heated high voltage power rectifier and was designed for transmitter use. It has a rating of 180 Watts. The maximum reservoir capacitor is specified at 4 µF and the rectifier needs a series resistance of 250 Ω to limit peak current.
The data-sheet indicates that the 5R4WGB has been individually inspected for manufacture details to ensure a long stable working life.
The 12-83 looks like a manufacturing date.
The last test results.
The top mica showing the tensioning springs holding the oxide coated filament in the end hooks.
Direct top view. Note how thin the anode metal is.
The wide glass tube envelope is 45 mm in diameter, and excluding the IO base pins is 113 mm tall.
Reference: Data-sheet. Type 5R4WGB was first introduced in 1958. See also1958 adverts.
