Matched Pair CBS Hytron 12SN7 12SN7GT Vacuum Tubes Black T Plates Tung-Sol NOS NIB There are three new old

There are three new old stock

They have 1-43 188-5 and 3-52 188-5 date/provenance codes

These six Cunningham C-324 globe

new in box Sylvania 14C5 tubes tested to spec on our Paul Hart-calibrated TV7/U

new in box RCA 6U10 tube tested to spec on our Paul Hart-calibrated TV7/U

Matched Pair CBS Hytron 12SN7 12SN7GT Vacuum Tubes Black T Plates Tung-Sol NOS NIB There are three new oldThis matched pair of CBS Hytron 12SN7GT dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 75 70 for Tube One and 77 72 for Tube Two where minimum (65%) is 50 50 and 100% is 77 77. They have black T plates; D getters; steel support rods; excised chevrons in their top mica spacers as well as 210 5439 and 5413 provenance date codes, respectively. I have