Matched Pair National Union NU 6J7 6J7GT Vacuum Tubes Valves Glass Bottles Tung-Sol Gebraucht copiously-illustrated book is in excellent

copiously-illustrated book is in excellent condition

new in box milspec RCA JAN-CRC-12SW7 tubes tested to spec on our Paul Hart-calibrated TV7/U

each with three rectangular holes

generous flashing and an anode radiator for cooler operation and longer life

new in box matched pair of RCA steel plate 6AK5 tubes was tested on our Paul Hart-calibrated TV7/U tester for shorts

Matched Pair National Union NU 6J7 6J7GT Vacuum Tubes Valves Glass Bottles Tung-Sol Gebraucht copiously-illustrated book is in excellentThis matched pair of National Union glass bottle 6J7GT tubes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 42 while Tube Two measured 42 as well where minimum (65%) is 31. I have played them in my Musical Paradise 301 MK 3 with adapters (not included) as 6SJ7 substitutes and they sound excellent airy with excellent dynamics and signal bandwidth. They are a tad