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

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

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

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

(1) Tested Motorola 6DX8 Tube Date Code 7M-1584 Japan Triode Pentode Tube

(1) Tested Sylvania 6CU8 Tube Date Code NR DEK Triode Pentode Vacuum Tube

(1) Tested Westinghouse 6JW8 Tube Date Code 81-09 Triode and Pentode Tube (b)

(1) Tested GE 6JV8 Tube and Box Date Code NJ General Electric Triode Pentode (a)