(1) Tested RCA 6CY5 Tube with Box Date Code DC Screen Grid Tetrode Tube

(1) Tested GE 6CY5 Tube Date Code RV General Electric Screen Grid Tetrode Tube

(1) Tested RCA 6CY5 Tube with Box Date Code DR Screen Grid Tetrode Tube

(1) Tested Sylvania 6CY5 Tube with Box Date Code ha ABO Tetrode Tube

(1) Tested GE 6GY6 Tube Date Code 5-48 General Electric 6GY6 Pentode Tube

(1) Tested GE 2CY5 Tube Date Code JT General Electric Sharp Cutoff Tetrode Tube

(1) Tested RCA 6CY5 Tube with Box Date Code DJ Sharp Cutoff Tetrode Tube

(1) Tested Raytheon 6CY5 Tube Japan with Box Date Code S-02 Tetrode Tube