4 Ken-Rad 6D6 Vacuum Tubes Valves Black Glass Lot of Four NOS-Testing 5Z4 Rectifier excellent flashing and what appears

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

US-made number / type 89 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

Tube Two probably has a piece of broken glass in it

Minimum (65%) is 57/57 and 100% is 88/88

it is probably plated

4 Ken-Rad 6D6 Vacuum Tubes Valves Black Glass Lot of Four NOS-Testing 5Z4 Rectifier excellent flashing and what appearsThis 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