National Union NU 6R7 6R7G Vacuum Tube Valve Shoulder Shape NOS NIB Casting Pearls 79/77 where minimum (65%) is

79/77 where minimum (65%) is 50/50

new in box Sylvania 6LU8 tube tested to spec on our Paul Hart-calibrated TV7/U

35 and 37 where minimum (65%) is 25

Tube One measured 60 while Tube Two measured 70 where minimum (65%) is 46 and 100% is 71

National Union NU 6R7 6R7G Vacuum Tube Valve Shoulder Shape NOS NIB Casting Pearls 79/77 where minimum (65%) isThis new old stock, new in box National Union 6R7 6R7G tube tested to spec on our Paul Hart calibrated TV7 U. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE "LOWTECHTWOO" AND OR CALL OR TEXT US AT 202 372 6931 IF YOU DO NOT SEE WHAT YOU NEED OR HAVE ANY QUESTIONS. 1. MOST FORMS OF SHIPPING EXCEPT MEDIA MAIL ARE AUTOMATICALLY INSURED UP TO $100. ETSY PURCHASE PROTECTION COVERS ITEMS