4 Ken-Rad 6D6 Vacuum Tubes Black Glass Lot of Four NOS-Testing 12B4A Gebraucht each having four stamped crosses:

each having four stamped crosses: two upside-down and two right-side up

new in box GE 6U8A (ECF82 / 6AX8 / 5KD8 / 6KD8) pentode/triode was tested on our Paul Hart-calibrated TV7/U for shorts

These nine TCA UY-224 globe

This matched trio of Sylvania 12BY7 / 12BY7A tubes was tested on our Paul Hart-calibrated TV7 for shorts

" "I Shall Go Down The Street

4 Ken-Rad 6D6 Vacuum Tubes Black Glass Lot of Four NOS-Testing 12B4A Gebraucht each having four stamped crosses:This lot of four black glass Ken Rad 6D6 tubes was tested on our Jackson 648 Mutual Conductance tester for shorts, gas and transconductance. There were no shorts or gas. They tested (from left to right) as follows: 81%, 106%, 109%, and 117% respectively. New nominal is within a standard deviation of 1600 and the Jackson expresses this as a percentage. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT