(1) Tested Tung Sol 5U8 Tube Date Code KA3 Triode Pentode Tube

(1) Tested Rad-Tel 6X8 Tube Date Code 5-66 6X8 Triode Pentode Converter Tube

(1) Tested Tung Sol 5U8 Tube with Box Date Code NC1 Triode Pentode Tube

(1) Tested Raytheon 6AN8 Tube Date Code 643 Triode Pentode Tube

(1) Tested Sylvania 5X8 Tube Date Code GL ELM Triode Pentode Converter Tube

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

(1) Tested Strong Sylvania 6JC8 Tube Date Code NR JAG Triode Pentode Tube

(1) Tested GE 6JV8 Tube and Box Date Code NJ General Electric Triode Pentode (b)