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

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

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

(1) Tested RCA 6BR8A Tube with Box Date Code CB RCA Triode Pentode Tube

(1) Tested RCA 6AZ8 Tube with Box Date Code KG Medium Mu Triode Cutoff Pentode

(1) Tested RCA 6GH8A Tube with Box Date Code HE Triode Sharp Cutoff Pentode Tube

(1) Tested RCA 5BR8 Tube with Box Date Code AQ Medium Mu Triode Cutoff Pentode

(1) Tested RCA 6BH11 Tube with Box Medium Mu Twin Triode Sharp Cutoff Pentode