Matched Pair Sylvania 6BL7 6BL7GT Vacuum Tubes Black Plate Triple 3 Mica NOS NIB Matched Pair 6AU6 new in box National Union

new in box National Union 14J7 tube tested to spec on our Paul Hart-calibrated TV7/U

Bottom: crenelated

pops and ticks

Please refer to the pictures to confirm this album and its contents as my Bulgarian is worse than bad

Transconductance measured 49/56

Matched Pair Sylvania 6BL7 6BL7GT Vacuum Tubes Black Plate Triple 3 Mica NOS NIB Matched Pair 6AU6 new in box National UnionThis new old stock, new in box (for Tube One (centering pin missing)) matched pair of Sylvania 6BL7GT dual triodes was tested on our TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One (centering pin missing) measured 46 46 while Tube Two measured 50 46 where minimum (65%) is 25 25 and 100% is 39 39. These tubes have copper support rods; beefy black ladder plates; three (rather than two) mica spacers for improved