Beam tetrode used in the output stage of battery powered radios. Equipped with a centre-tapped filament allowing use in either a parallel filament arrangement running from a 1.5 volt battery or a series arrangement with other 50 mA filaments.
1.4/2.8 V directly heated cathode.
Series filament strings were used in radios designed to be operated from either battery or mains power.
Manufacturer: Radio Corporation of America, USA
Cylindrical glass bulb on octal base with six pins present.
Bulb: 3Q5GT Base: RCA/RADIOTRON/ELECTRON/TUBE/(RCA logo)/MADE IN U.S.A./3Q5GT(paper label)
Type of item
72 mm (Length), 32 mm (Outside Diameter)