Matched Pair Tung-Sol 6K6 6K6GT Black Bottles Vacuum Tubes NOS-Testing Ken-Rad 35Z6 NOS NIB This tube has steel support

This tube has steel support rods

excised chevrons in their top mica spacers as well as 210 5439 and 5413 provenance/date codes

Tube Two measured 2160/26

Tube One measured 1940 micromhos

mesh plates

Matched Pair Tung-Sol 6K6 6K6GT Black Bottles Vacuum Tubes NOS-Testing Ken-Rad 35Z6 NOS NIB This tube has steel supportThis 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 25. 3 milliamps' plate current and measured 2060 micromhos. Tube Two measured 25. 4 2080. New nominal is within one standard deviation of 1900. These tubes have pretty black bottles that entirely cover the top half of the tubes;