Matched Pair Sylvania 6K6 6K6GT Vacuum Tubes Valves US-Made Gebraucht This beautiful new old stock-testing

This beautiful new old stock-testing Sylvania-MANUFACTURED

new in box Sylvania 6V4 / EZ80 rectifier tube tested to spec on Paul Hart-calibrated TV7/U

52/34 and 56/47 where minimum (65%) is 40/45 and 100% is 62/69

There is some marking in the first twenty pages or so

new in box RCA 17AY3 / 17AY3A / 17BS3 / 17BS3A tubes tested to spec on our Paul Hart-calibrated TV7/U

Matched Pair Sylvania 6K6 6K6GT Vacuum Tubes Valves US-Made Gebraucht This beautiful new old stock-testingThis matched pair of Sylvania MANUFACTURED, Philco LABELED 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 18. 4 milliamps' plate current and measured 1460 micromhos. Tube Two measured 19. 5 1710. New nominal is within one standard deviation of 1900. These tubes have copper support rods; rectangular mica spacers; anode radiators