Matched Quad RCA 6FQ7 / 6CG7 Vacuum Tubes Triple 3 Mica This almost-perfectly-matched pair of Sylvania

This almost-perfectly-matched pair of Sylvania black plate 6C4 triodes was tested on our Paul Hart-calibrated TV7/U for shorts

This mono LP has some surface noise in the quiet passages and warrants a 7

new in box Mullard 6HA5 / EC900 tube tested to spec on our Paul Hart-calibrated TV7/U

This matched pair of Sylvania 6AU6A tubes was tested on our Paul Hart-calibrated TV7/U for shorts

Transconductance measured 45 in Section One and 50 in Section Two for Tube One and 50/44 in Tube Two where minimum (65%) is 50/50 and 100% is 77/77

Matched Quad RCA 6FQ7 / 6CG7 Vacuum Tubes Triple 3 Mica This almost-perfectly-matched pair of SylvaniaThis matched pair of RCA 6FQ7 6CG7 dual triodes was tested on our TV7 U for shorts, gas and transconductance. There were no shorts or gas and their readings are as follows: Tube One measured 69 72 while Tube Two measured 69 76. Tubes Three and Four measured 73 70 and 75 72, respectively, where minimum (65%) is 50 50 and 100% is 77 77. These tubes have steel support rods; ladder plates; side D getters and excellent flashing. As I write, I am playing