3 RCA Number Type 37 #37 Vacuum Tubes Valves Black Plate ST Shape Lot Of Three London International GM-BRANDED 6SK7 tested as good

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

(New US-made 6V6s typically test with plate current from the mid-teens to mid-thirties with transconductance from 2300 micromhos or so

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

they can put out as much as 2A3s and fell into disfavor because of socket supply issues

The spine is in fine shape with no loose pages and the dust jacket has only a few

3 RCA Number Type 37 #37 Vacuum Tubes Valves Black Plate ST Shape Lot Of Three London International GM-BRANDED 6SK7 tested as goodThese 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