4 National Union NU Number / Type 41 #41 Vacuum Tubes Lot Of Four Farewell Petersburg likely Tung-Sol-MANUFACTURED) measured 33 where

likely Tung-Sol-MANUFACTURED) measured 33 where minimum (65%) is 22

They tested as follows: 53

plate current

They have 4-39 188-5 and 3-43 188-5 date codes/EIA code

Bottom: crenelated

4 National Union NU Number / Type 41 #41 Vacuum Tubes Lot Of Four Farewell Petersburg likely Tung-Sol-MANUFACTURED) measured 33 whereThese four National Union type number 41 tubes tested as follows on our Paul Hart calibrated TV7 U: 46, 47, 48 and 48 where minimum (65%) is 40 and 100% is 62. 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