Matched Pair RCA 6F6 6F6G Vacuum Tubes ST Shoulder Shape T33 for Backup The bottle was already tightly-affixed

The bottle was already tightly-affixed to the base

These US-made 12SF7 tubes were tested on our Paul Hart-calibrated TV7 for shorts

Tube One measured 65/66 while Tube Two measured 69/64 where minimum (65%) is 56/56 and 100% is 87/87

outstanding flashing and a P1 date code

Matched Pair RCA 6F6 6F6G Vacuum Tubes ST Shoulder Shape T33 for Backup The bottle was already tightly-affixedThis matched pair of RCA MANUFACTURED 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 (Emerson LABELED, RCA MANUFACTURED) drew 16. 6 milliamps' plate current and measured 1800 micromhos while Tube Two measured 17. 6 1780 where new 6F6s measure from approximately 2000 micromhos with plate current draw in the 20s. These tubes have 274 649