Test results will vary between testers as it is not an exact science and all testers have their limitations. Mutual Conductance (GM)Test: 97.1 & 39.1 ( 72 & 42 = NOS AVERAGE & 47 & 27 = Good MINIMUM).
NOS International Servicemaster 6GV8 / ECL85 Vacuum tube
NOS International Servicemaster 6GV8 / ECL85 Vacuum tube
6GV8/ECL85 VERY RARE BRAZIL FACTORY Amperex IBRAPE Sao Paulo Tube Triode Pentode
The tube also has Brazil labeled on the tube.