Width & Focus in DuMont RA-103

[Phil Nelson]

I assume this is a rebuild sticker, which says 12JP4. It's on the bell, halfway under the cushioned mounting strap.

It would be easy enough to take off the ion trap and see what happens.

When I first got the set, I feared it might have a bad video problem, since there was nothing on the screen but extremely faint, wandering mush. Small adjustments of the ion trap did nothing. At one point, I tried moving the trap around a lot more and a bright picture suddenly snapped in.

The trap was nowhere near working in its original position. Now the magnet is rotated roughly 180 degrees and it has been moved slightly front or back. Of course, a trap could have been nudged by accident in moving. The previous owner had the chassis in and out of the cabinet at least a couple of times.

I don't know who would put an ion trap on a CRT that doesn't use one. Maybe the same guy who hotwired the ginormous 10 mfd cap in the power supply.

Phil