Matched Pair National Union NU Number / Type 76 #76 Vacuum Tubes Valves 7AH7 Sylvania gas and transconductance

gas and transconductance

noise or gas and it tested as follows:

new in box 6SR7 tubes tested to spec on our Paul Hart-calibrated TV7/U

new in box Sylvania 25Z5 tubes tested to spec on our Paul Hart-calibrated TV7/U

These three 6G6G tubes were tested on our Paul Hart-calibrated TV7 for shorts gas and transconductance

Matched Pair National Union NU Number / Type 76 #76 Vacuum Tubes Valves 7AH7 Sylvania gas and transconductanceThis matched pair of National Union type 76 triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 49 for Tube One and 52 for Tube Two where minimum (65%) is 36 and 100% is 55. These tubes have shiny, dark gray, rounded plates; crenelated, top, rectangular mica and smooth rectangular bottom spacers and excellent flashing. I have played them in my Radio Craftsmen