Matched Pair National Union NU 45 #45 Vacuum Tubes

Matched Pair National Union NU 45 #45 Vacuum TubesThis pair of National Union black plate 45 output triode was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 62 while Tube Two measured 69. Minimum (65%) is 47 and 100% is within a half standard deviation of 72 or so. These tubes have banded phi shaped mica spacers; GT and JY date codes; dimpled sheet getters; ribbed, charcoal plates and excellent flashing WE HAVE SCORES OF

NOR IS THERE A WAY TO DETERMINE WHETHER THEY MAY HAVE FATAL FLAWS

It has a shoulder / ST bottle

engraved bases and narrow rectangular mica spacers

Tube One measured 43 while Tube Two measured 58 were minimum (65%) is 36 and 100% is 55

rounded rectangle

new in box milspec JAN-CKR-9006 / JRC-9006 9006 tubes tested to spec on our Paul Hart-calibrated TV7/U

Tube One measured 81 while Tube Two measured 88

new in box GE 12DK7 tubes tested to spec on our Paul Hart-calibrated TV7/U

They tested (from left to right) as follows: 52 and 55 where minimum (65%) is 40 and 100% is 62

This hard cover book is in excellent condition

They have engraved / hot-stamped bases on is Champion-branded and the other is Zenith

Two are civilian and two are milspec