Matched Pair National Union NU Number Type 37 #37 Vacuum Tubes Valves Black Plate Shoulder ST Shape NOS-Testing

Matched Pair National Union NU Number Type 37 #37 Vacuum Tubes Valves Black Plate Shoulder ST Shape NOS-TestingThis new old stock testing matched pair of National Union MANUFATURED Type 37 triodes was tested on our Paul Hart calibrated TV7 For shorts, gas and transconductance. There were no shorts or gas. They measured 36 and 37 (RCA LABELED, NU MANUFACTURED) where minimum (65%) is 23. They have black plates; dimpled sheet getters; old fashioned, coke bottle shape glass envelopes and terrific flashing. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT

These thirteen US-made 5T8 tubes tested to spec on our Paul Hart-calibrated TV7/U

They measured 105/87 for Tube One and 107/84 for Tube Two

Transconductance measured 64 for Tube One and 68 for Tube Two tubes where minimum (65%) is 40

Three are milspec

new in box Sylvania 17BW3 tested to spec on our Paul Hart-calibrated TV7/U

It measured 79 where minimum (65%) is 32 and 100% is 49

It is extremely-quiet with nice fidelity

The records are in excellent shape and were well-taken-care-of

new in box Realistic (Radio Shack) Gold Clad 6S4 / 6S4A tube tested to spec on our Paul Hart-calibrated TV7/U

These six Cunningham C-324 globe

WE HAVE HAD FEWER THAN A DOZEN LESS-THAN-FOUR-STAR REVIEWS OR HAVE LOST A CUSTOMER BECAUSE I REFUSED TO EITHER ISSUE A REFUND FOR A TUBE THAT WENT BAD AFTER IT HAD BEEN USED OR A BUYER KNEW NOTHING ABOUT TUBE REBRANDING AND CLAIMED THAT SOMETHING MADE BY TUNG-SOL AND BRANDED BY EMERSON WAS MADE BY EMERSON

Transconductance measured 2640 and 2680 micromhos