[Tubejunke]

I never really understood the whole double ion trap "beam bender" magnet thing. I mean any tube guide shows that application on 10BP4s, but I have one with only a single trap and have seen others. I would have to take a look at my 12LP4 in a '50 RCA to see what type it has.

Back to the topic: That positioning you mention of having your trap all the way back against the tube plug is something that I have seen more than once. Either way you look at it, it's wrong. The last set that I can remember specifically the conditions that were at hand was a mid/later 50s Magnavox 21". The set worked fine till the flyback melted. I did some repair attempts at piecing together the fly as opposed to troubleshooting and repairing what was causing the fly to heat up. Long time ago.

Anyway, at some point it seemed that the set might work and was producing some level of high voltage. I STILL need a H.V. probe BADLY! LOL! The voltage was low, but for some reason of I pulled that ion trap all the way back to the plastic plug at the very end of the glass I produced a raster. Not specifically bright, but a raster.

Years later after the Internet came into being a household fixture, I was able to locate a flyback which probably never would have happened without the WWW. Put that in and changed a few caps and I had closer to correct high voltage. Again, no probe but you can sort of tell. Long story short, at that point I had to move the trap back to its correct position about .5 inches in toward the yoke.