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

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

(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 6AZ8 Tube with Box Date Code KG Medium Mu Triode Cutoff Pentode

(1) Tested RCA 6JV8 Tube and Box Date Code BZ Triode Pentode Tube (b)

(1) Tested Tung-Sol 6AW8A Tube Tung Sol 6AW8 A High Mu Triode Cut Off Pentode

(1) Tested Tung-Sol 6AW8A Tube Date Code PRI 6AW8 A High Mu Triode Pentode