(1) Tested Garod 6AC7 Tube Date Code 0-09 Garod 6AC7 Sharp Cut Off Pentode (b)

(1) Tested RCA 6AC7 Tube Date Code 352 RCA 6AC7 Sharp Cutoff Pentode Tube

(1) Tested Westinghouse 6AC7 Tube Date Code 1-22 6AC7 Sharp Cut Off Pentode Tube

(1) Tested Garod 6AC7 Tube Date Code 0-09 Garod 6AC7 Sharp Cut Off Pentode (a)

(1) Tested RCA 6AU6 Tube Date Code 504 RCA 6AU6 Sharp Cut Off Pentode Tube

(1) Tested Dumont 6AC7 Tube Date Code 4-14 Dumont 6AC7 Sharp Cutoff Pentode Tube

(1) Tested Tung Sol 6AC7 Tube Date Code 540-3 Sharp Cutoff Metal Pentode Tube

(1) Tested Truetone 6AC7 Tube with Box Code 517 Sharp Cut Off Pentode Tube