(1) Tested Sylvania 12BR7 Tube with Box Date Code bf JEK Twin Diode Triode Tube

(1) Tested RCA 6BF6 Tube Date Code KG Twin Diode Medium Mu Triode Tube

(1) Tested RCA 8CM7 Tube with Box Date Code NI RCA Double Triode Tube

(1) Tested Strong RCA 8GN8 Tube with Box Date Code AV Triode Pentode Tube

(1) Tested Sylvania 3AV6 Tube with Box Date Code ACG Twin Diode High Mu Triode

(1) Tested Sylvania 6BJ8 Tube with Box Date Code ER DHL Twin Diode Triode

(1) Tested RCA 6AU8 Tube with Box Date Code KQ Triode Pentode Tube

(1) Tested RCA 5AN8 Tube with Box Date Code KQ Triode Pentode Tube