Matched Pair General Electric GE 12SN7 12SN7GTA Vacuum Tubes NOS NIB 81266-1 Stereo LP This tube has two spy

This tube has two spy holes per plate side

This pair of Tung-Sol type 76 triodes was tested on our Paul Hart-calibrated TV7/U for shorts

milspec Sylvania JHS-12AT7WA (12AT7 / ECC81) dual triode was tested on our Paul Hart-calibrated TV7/U for shorts

The used Westinghouse 12D4 tested as Good on the English scale on our Hickok 800 and had no emissions drop with the filament at five rather than 6

Matched Pair General Electric GE 12SN7 12SN7GTA Vacuum Tubes NOS NIB 81266-1 Stereo LP This tube has two spyThis new old stock, new in box matched pair of GE MANUFACTURED 12SN7GTA dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 82 87 for Tube One and 84 87 for Tube Two (Zenith LABELED, GE MANUFACTUREDwhere minimum (65%) is 50 50. They have gray, ladder plates; crenelated, round top mica spacers with an excised square and circle each, O getters; copper