Matched Pair CBS Hytron 12SN7 12SN7GT Vacuum Tubes Black T Plates Number 1 In F Major Three are milspec (one is

Three are milspec (one is a JAN-CRC-6AB7Y)

Please note Tube Two’s centering pin is missing

I just cleaned this four LP set on my VPI 16

well-constructed tubes with Micanol bases

Tube Two measured 1740/19

Matched Pair CBS Hytron 12SN7 12SN7GT Vacuum Tubes Black T Plates Number 1 In F Major Three are milspec (one isThis 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