The 5R4GY is a 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.
See also5R4WGY for a later version of this design.
In this design the flat side of the anode is to the centre with the flange and support to the outside nearest the glass.
The ribbon filament is tensioned by springs that sit below the top mica. Most rectifiers with tape filaments have the springs above the top mica.
The classic envelope is 50 mm diameter, and excluding the IO base pins, is 115 mm tall.
