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

(1) Tested GE 6EB8 Tube Date Code JU 6GN8 High Mu Triode Pentode Tube

(1) Tested Westinghouse 6EB8 Tube Date Code 69-22 High Mu Triode Pentode Tube

(1) Tested GE 6EB8 Tube General Electric 6GN8 High Mu Triode Pentode Tube

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

(1) Tested Philco 6JE8 Tube Date Code EBF High Mu Triode Sharp Cutoff Pentode

(1) Tested Cornell 6EB8 Tube Date Code XRMT-PNH 6GN8 High Mu Triode Pentode Tube

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