The JJ 5Y3S Vacuum Tube is a glass octal
type used in the power supplies of radio equipment
having moderate DC requirements. They require an octal
socket. Vertical tube mounting is preferred, but
horizontal opration is permissible if pins 2 and 8 are
in horizontal plane.
Electrical Data:
Heater Voltage ................................ 5.0 V
Heater Current ................................ 2.0 A
Preferred Substitutes .............. 5Y3G, 5Y3S,
5AX4, 5AZ4, 5R4
Substitutes .................................. 5U4