Sylvania Number / Type 37 #37 Vacuum Tube NOS NIB Anton Grigoriev It measured 36/39 where minimum

It measured 36/39 where minimum (65%) is 18/18 and 100% is 28/28

It measured 42/49 where minimum (65%) is 50/50 and 100% is 77/77

They have an extra mica spacer for vibration suppression

beefy black plates: side O getters

Sylvania Number / Type 37 #37 Vacuum Tube NOS NIB Anton Grigoriev It measured 36/39 where minimumThis new old stock, new in box Sylvania Number 37 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 UP