And the story of the dead Tesla 4654. This tube lost it's vacuum because I was not careful enough when removing it from adapter and touched the glass. The base got loose and started to rotate on the glass, not 180 degrees but around let's say 45 degrees. Not much, at first I said I'll glue it. Put it on the drawer and when I came back to it I realized it was too late.
Loose base made the tube loose also it's vacuum. Now, I remember I have a lot of octal tubes where the base is moving, all work fine and none of them lost vacuum because of this until now but you have to be careful not to touch the glass and always remove by dragging from the base. Here it is more complicated to do this since the base enters inside the adapter/socket of the amp for around 70% of the height. If you have bigger hands or like me you are not careful, something like this can happen. So, please be careful never to drag/touch the glass when operating such an european side contact tube. I do not really know how each side contact is tied to the internal parts and if this is a consequence of this type of base (and all with this base are prone to this) or if it was a special case only happening on this manufacturer. I will inform if I will have other unfortunate events like this, until then be careful. Even using a small screwdriver to remove the tube from the socket or adapter is not quite a solution due to the form and way these enter one into another.
Loose base made the tube loose also it's vacuum. Now, I remember I have a lot of octal tubes where the base is moving, all work fine and none of them lost vacuum because of this until now but you have to be careful not to touch the glass and always remove by dragging from the base. Here it is more complicated to do this since the base enters inside the adapter/socket of the amp for around 70% of the height. If you have bigger hands or like me you are not careful, something like this can happen. So, please be careful never to drag/touch the glass when operating such an european side contact tube. I do not really know how each side contact is tied to the internal parts and if this is a consequence of this type of base (and all with this base are prone to this) or if it was a special case only happening on this manufacturer. I will inform if I will have other unfortunate events like this, until then be careful. Even using a small screwdriver to remove the tube from the socket or adapter is not quite a solution due to the form and way these enter one into another.