4 Ken-Rad 6D6 Vacuum Tubes Valves Black Glass Lot of Four NOS-Testing 5Z4 Rectifier new in box Cunningham 14F7

new in box Cunningham 14F7 tube tested to spec on our Paul Hart-calibrated TV7/U

Tube Two probably has a piece of broken glass in it

excellent flashing and what appears to be a US Navy logo on the base

Tube Two measured 19

4 Ken-Rad 6D6 Vacuum Tubes Valves Black Glass Lot of Four NOS-Testing 5Z4 Rectifier new in box Cunningham 14F7This 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. BECAUSE OF THE BIZARRE, INTRUSIVE AND DRACONIAN GERMAN PACKAGING REGULATIONS AND THE SEVERE FINES AND