Matched Pair RCA 12SN7 12SN7GTA Vacuum Tubes Black Plate NOS NIB Tung-Sol 6K6 These four metal base National

These four metal base National Union 6Q7GT tubes tested to spec on our Paul Hart-calibrated TV7/U

They measured 82/76 for Tube One and 85/74 for Tube Two

Transconductance readings are 25

though they are labeled differently

These lot of six new old stock

Matched Pair RCA 12SN7 12SN7GTA Vacuum Tubes Black Plate NOS NIB Tung-Sol 6K6 These four metal base NationalThis new old stock, new in box matched pair of RCA 12SN7GTA dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 76 76 and Tube Two measured 79 77 where minimum (65%) is 50 50. They have short bases; tall bottles; D getters; steel support rods; DB and CV batch codes, respectively, and their top mica spacers have two X patterns incised into them. I am playing them