10BP4 without Ion Trap?

[Eric H]

The Dumont 12JP4 is straight gun/non aluminized.

They used a relay to keep the tube off till the sweep circuits were operating and to cut it off when shut down to prevent burning.

Originally posted by dewickt
The reverse is also true, a bent gun tube (non aluminized) will have no picture with magnets removed, only way to get brightness is to use a magnet on the early tubes. My stromberg has no magnet but uses electromagnetic focus, has burn size of silver dollar right in the middle of the tube, when you turn it off it nails the phosphor....