(1) Tested Motorola 6BL8 Tube Date Code 7M-431 Made in Japan Triode Pentode Tube

(1) Tested Strong Sylvania 6JC8 Tube Date Code NR JAG Triode Pentode Tube

(1) Tested Sylvania 6JC8 Tube with Box Date Code NR EDF Triode Pentode Tube

(1) Tested Sears 8JV8 Tube Japan Date Code 6K High Mu Triode Cutoff Pentode

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

(1) Tested Very Strong GE 6JC8 Tube with Box Date Code CV Triode Pentode Tube

(1) Tested GE 6JV8 Tube and Box Date Code NJ General Electric Triode Pentode (b)

(1) Tested GE 6JC8 Tube with Box Date Code SC General Electric Triode Pentode