(1) Tested RCA 6AX4GTB Tube Date Code DV Coin Base RCA 6AX4 GTB Rectifier Tube

(1) Tested RCA 6AX4GTB Tube Date Code AK 6AX4 GTB Rectifier Tube

(1) Tested Raytheon 6AX4GTB Tube with Box Code J-22 Japan 6AX4 GTB Rectifier (b)

(1) Tested Westinghouse 6AX4GTB Tube with Box Date Code 70-52 6AX4 GTB Rectifier

(1) Tested Truetone 6AX4GTB Tube with Box Date Code 6535 6AX4 GTB Rectifier

(1) Tested Truetone 6AX4GTB Tube with Box Date Code 6513 6AX4 GTB Rectifier Tube

(1) Tested Silvertone 6AX4GTB Tube Date Code 274 Silvertone 6AX4 GTB Rectifier

(1) Tested Lindal 6AX4GTB Tube & Box Date Code 9J Japan 6AX4 GTB Rectifier Tube