The Sylvania 5Y4-G is a classic full-wave rectifier tube found in a wide range of vintage radios, amplifiers, test equipment, and other vacuum tube electronics. Manufactured in the USA during the golden age of tube production, Sylvania tubes earned a reputation for dependable performance and long service life.
 
This tube has been individually tested on a calibrated EICO Model 625 tube tester and produced a strong GOOD reading, making it an excellent choice for replacing a weak or failed rectifier while preserving the originality of your vintage equipment.