(1) Tested Philco 6AT6 Tube Date Code 50-26 Twin Diode High Mu Triode Tube

(1) Tested RCA 6AT6 Tube with Box Date Code BF Twin Diode High Mu Triode Tube

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

(1) Tested RCA 6BJ8 Tube Date Code AC RCA Twin Diode Triode Tube

(1) Tested Philco 6AT6 Tube Date Code 50-13 Dual Diode High Mu Triode Tube

(1) Tested RCA 6EB8 Tube Date Code AP High Mu Triode Pentode Tube

(1) Tested RCA 6AN4 Tube Date Code KJ RCA High Mu Triode Tube

(1) Tested Strong Ken-Rad 12AT6 Tube Date Code 6-30 Twin Diode High Mu Triode