(1) Tested Westinghouse 6GH8A Tube with Box Date Code 70-22 Triode Pentode

(1) Tested RCA 6GH8A Tube with Box Date Code HE Triode Sharp Cutoff Pentode Tube

(1) Tested Lindal 6GH8A Tube with Original Box Triode Sharp Cutoff Pentode

(1) Tested Lindal 6GH8A Tube with Box Japan Code 448 Triode Sharp Pentode (a)

(1) Tested Zenith 6GH8A Tube Date Code 18-09 Halo Getter Triode Cutoff Pentode

(1) Tested Sylvania 6JC8 Tube with Box Date Code NR EDF Triode Pentode Tube

(1) Tested Lindal 6GH8A Tube Japan Code 448 Triode Sharp Cutoff Pentode (b)

(1) Tested Sylvania 12JN8 Tube with Box Date Code ZAB Triode Pentode Tube