The RV120/350 full wave rectifier was designed to work with a maximum reservoir capacitor of 32 µF and to have an effective series resistance of 100 Ohms. The RV120/350S was the same valve but fitted with a Ct8 side contact base cap.
The broad face of one section with the ribbon filament.
The folded anodes join to the supports along their length.
The dome with Type designation, the Tungsram name and Made in England.
Below the securing top mica is the ceramic pad that holds the four filament tension springs.
The classic envelope is 45 mm in diameter and, excluding the B4 base pins, is 106 mm tall.
References: Data-sheet & 1043. Type RV120/350 was first introduced in 1938. See also1938 adverts.