Matched Pair Groove Tube Fat Tone Premium 6V6 6V6S Uncle Doug Vacuum Tubes NOS-Testing 35L6 T25 They have engraved / hot-stamped

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

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

It has a banded

This Continental Electric JAN-C1K appears new

Matched Pair Groove Tube Fat Tone Premium 6V6 6V6S Uncle Doug Vacuum Tubes NOS-Testing 35L6 T25 They have engraved / hot-stampedThis 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