Aluminized vs Non Aluminized tubes
 

Here are some pictures I took illustrating the differences between an aluminized 10FP4 and a non aluminized 12LP4


This first pic is the 10FP4, you can see the shiny silvery coating inside, it extends all the way back past the anode connector.

Non coated 12LP4
 

This is a non aluminized 12LP4, you can see inside to the back side of the screen.

Straight gun
 

This is the gun in the 10FP4, note the elements all line up in a straight row, the picture itself is a little crooked however!

the "Bent" gun
 

This is the gun in the 12LP4

(again the picture is crooked, need a tripod!)
It's actually mounted straight in the neck of the tube but note the angled cuts in between the elements, this apparently has the same effect as if it were mounted crooked.

Some tubes actually do have the gun mounted at a noticeable angle.

The photos were helpful-I've read "bent gun" many times, and I've seen these guns but did not put 2+2 together. I was thinking of a different kind of bend, if that makes sense.

Now I am confused again because my 10BP4a has the coating like Erics 12LP4 where you can see through to the back of the screen. Another person said that the A suffix stood for alumanized when I question the need for an ion trap and what kind if needed (single or double) If mine is like yours than it must not be alumanized. Would that not mean a trap is needed? I'm never going to feel safe using this tube.....

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