05-13-2017, 12:01 PM
The blue tube is probably gassy and no good if the blue glow fills the space inside the tube. That means air has leaked inside and contaminated the vacuum. The fact that the blue tube is getting hotter is not a good sign.
If the blue glow is on part of the inside of the glass surface only and not filling the space then it is just harmless florescence caused by stray electrons hitting the glass.
If there is any doubt, replace the blue tube because a gassy one can go into a runaway condition where the current keeps rising until something eventually burns up.
If the blue glow is on part of the inside of the glass surface only and not filling the space then it is just harmless florescence caused by stray electrons hitting the glass.
If there is any doubt, replace the blue tube because a gassy one can go into a runaway condition where the current keeps rising until something eventually burns up.
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
