(1) Tested RCA 6CX8 Tube with Box Date Code CR 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 Strong RCA 8GN8 Tube with Box Date Code AV Triode Pentode Tube

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

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

(1) Tested Very Strong RCA 6GN8 Tube with Box Date Code DL High Mu Triode Tube