(1) Tested RCA 6CX8 Tube with Box Date Code CR Medium Mu Triode Pentode Tube

(1) Tested Sylvania 6JV8 Tube with Box Date Code NR AAA Triode Pentode Tube

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

(1) Tested ITT 6X8 Tube with Box Date Code 1109 Japan Triode Pentode Converter

One Excellent GE 6JZ8 Tube NOS NIB Triode/Pentode HICKOK 6000A Results

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

(1) Tested Zenith 6KT8 Tube and Box Red Letters Code 74-22 GE EIA Triode Pentode

(1) Tested Westinghouse 6GH8A Tube with Box Date Code 70-22 Triode Pentode