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

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

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

(1) Tested RCA 6BH8 Tube with Box Date Code BZ 6BH8 Triode Pentode Tube

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

(1) Tested RCA 6X8 Tube with Box Date Code 4-52 Triode Pentode Converter Tube

(1) Tested RCA 6AW8A Tube with Box Date Code BH 6AW8 A Triode Pentode (b)

(1) Tested GE 6JC8 Tube with Box Date Code SC General Electric Triode Pentode