(1) Tested Zytron 6BC5 Tube with Box Date Code 56-20 Sharp Cutoff Pentode Tube

(1) Tested Strong Philco 6BC5 Tube Date Code 61-47 Sharp Cutoff Pentode Tube

(1) Tested RCA 12AW6 Tube with Box Date Code 822 Sharp Cutoff Pentode Tube

(1) Tested RCA 3CE5 Tube with Box Date Code MG Sharp Cutoff Pentode Tube (b)

(1) Tested RCA 6HS8 Tube with Box Date Code AR Sharp Cutoff Twin Pentode Tube

(1) Tested Silvertone 6BC5 Tube Date Code 312 Sharp Cutoff Pentode Tube

(1) Tested Philco 6BC5 Tube Date Code 5311 Sharp Cutoff Pentode Tube

(1) Tested National Union 6BC5 Tube Date Code 533 Sharp Cutoff Pentode Tube