Zenith 6K6 6K6G Vacuum Tube Black And Silver Glass Shoulder ST-Shape NOS-Testing Guest Star new in box National Union

new in box National Union type 43 tubes tested to spec on our Paul Hart-calibrated TV7/U

new in box Tung-Sol 6SF5GT tested to spec on our Paul Hart-calibrated TV7/U

Transconductance measured 3900/4500 micromhos

This new old stock-testing matched pair of RCA 12SN7GT dual triodes was tested on our Paul Hart-calibrated TV7/U for shorts

Tube Three measured 62

Zenith 6K6 6K6G Vacuum Tube Black And Silver Glass Shoulder ST-Shape NOS-Testing Guest Star new in box National UnionThis new old stock testing Zenith 6K6 6K6G tube was tested on our Maxi Matcher II with 325 volts on the plates and a bias of 36 volts for shorts, gas and transconductance. There were no shorts or gas and it measured 1800 micromhos and drew 32. 3 milliamps' plate current. (New nominal transconductance is within one standard deviation of 1900.) WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY