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

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

(1) Tested Sharp Japan 17JZ8 Tube Date Code 8-7 Medium Mu Triode Power Pentode

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

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

(1) Tested Raytheon 6AN8 Tube Date Code 643 Triode Pentode Tube

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

(1) Tested GE 6KA8 Tube with Box Great Britain Date Code HI Triode Pentode