Matched Pair Tung-Sol 6K6 6K6GT Black Bottles Vacuum Tubes NOS-Testing T13 60/40 and 64/50 where minimum

60/40 and 64/50 where minimum (65%) is 50/50 and 100% is 77/77

new in box GE 12AV6 tubes tested to spec on our Paul Hart-calibrated TV7/U

new in box Zenith 6JH8 tubes tested to spec on our Paul Hart-calibrated TV7/U

This matched pair of CBS-Hytron 12SN7GT dual triodes was tested on our Paul Hart-calibrated TV7/U for shorts

new in box US-made 6CM7 tubes tested to spec on our Paul Hart-calibrated TV7/U

Matched Pair Tung-Sol 6K6 6K6GT Black Bottles Vacuum Tubes NOS-Testing T13 60/40 and 64/50 where minimumThis new old stock TESTING matched pair of Tung Sol 6K6GT 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 26 milliamps' plate current and measured 2030 micromhos. Tube Two measured 26. 1 2000. New nominal is within one standard deviation of 1900. These tubes have pretty black bottles that entirely cover the top half of the tubes; copper