Matched Pair Sylvania 6F6 6F6G Vacuum Tubes Black Plates Clear Shoulder / ST Bottles RCA Octal new in box Tung-Sol 50B5

new in box Tung-Sol 50B5 tube tested to spec on our Paul Hart-calibrated TV7/U

Fortunately the libretto is present and in great shape

even though they test on the cusp

These three RCA large logo 6F5s were tested on our Paul Hart-calibrated TV7/U for shorts

Matched Pair Sylvania 6F6 6F6G Vacuum Tubes Black Plates Clear Shoulder / ST Bottles RCA Octal new in box Tung-Sol 50B5This matched pair of Sylvania 6F6G tubes was tested on our Maxi Matcher 325 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. 2 milliamps' plate current and measured 1910 micromhos while Tube Two measured 27. 4 1930 where new 6F6s measure from approximately 2000 micromhos with plate current draw in the 20s. These tubes have black, three hole plates; copper support rods;