(1) Tested Relay 6CX8 Tube Date Code 6-66 Medium Mu Triode Pentode Tube

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

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

(1) Tested RCA 6EH8 Tube with Box Date Code CQ Triode Pentode Vacuum Tube

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

(1) Tested RCA 6EA8 Tube with Box Medium Mu Triode Sharp Cutoff Pentode Tube

(1) Tested RCA 6JV8 Tube with Box High Mu Triode Sharp Cutoff Pentode Tube

(1) Tested RCA 6JN8 Tube Date Code BW Triode Pentode Vacuum Tube