Matched Pair Groove Tube Fat Tone Premium 6V6 6V6S Uncle Doug Vacuum Tubes NOS-Testing 35L6 T25 Transconductance measured 81/82 for Tube

Transconductance measured 81/82 for Tube One and 81/85 for Tube Two

They have engraved / hot-stamped bases on is Champion-branded and the other is Zenith

new in box milspec RCA 1D8GT / VT-148 tested to spec on our Paul Hart-calibrated TV7/U

This Tung-Sol 0B3 / OB3 tube tested to spec on our Paul Hart-calibrated TV7/U

Matched Pair Groove Tube Fat Tone Premium 6V6 6V6S Uncle Doug Vacuum Tubes NOS-Testing 35L6 T25 Transconductance measured 81/82 for TubeThis matched pair of Groove Tube Fat Tone 6V6 S output tubes was tested on our Maxi Matcher 400 volts on the plates and a bias of 36 volts for shorts, gas and transconductance. There were no shorts or gas. Tube One drew 30 milliamps with a transconductance of 3350 micromhos while Tube Two measured 34. 4 3500. (New US made 6V6s typically test with plate current from the mid teens to mid 30s with transconductance from 2300 micromhos or so.) These tubes