3 RCA Number Type 37 #37 Vacuum Tubes Valves Black Plate ST Shape Lot Of Three London International These nine National Union number

These nine National Union number / type 27 tubes tested as good on our Paul Hart-calibrated TV7/U

59-43 188-5 and 5-48 188-5 date/provenance codes

GM-BRANDED 6SK7 tested as good on our Paul Hart-calibrated TV7/U

milspec GE JG-6X4WA tested to spec on our Paul Hart-calibrated TV7/U

3 RCA Number Type 37 #37 Vacuum Tubes Valves Black Plate ST Shape Lot Of Three London International These nine National Union numberThese three RCA Type 37 triodes were tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. They measured 23, 31 and 39 where minimum (65%) is 23. They have black plates; dimpled sheet getters; old fashioned, coke bottle shape glass envelopes and terrific flashing. 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