12at7wc tube NOS Sylvania mil specs black plate matched pair guitar amplifier

2 tubes 12at7wc Sylvania military specification JAN Joint Army Navy 

same code 1-75 with own military carton boxes

same inner structure

black plates

professional tubes high quality

tested strong & balanced tubes over tube tester Hickok TV7D/U:

test results 

tube 1 = 78 & 80 (reference good at 50 & 50)

tube 2 = 84 & 84 (reference good at 50 & 50)

preamp tubes military selected 

box 185