Sylvania 1-076 arrived!

[jeyurkon]

I installed the 12LP4 tonight by moving the bridge to the next set of mounting holes back. By the way, there are another set of holes that would accommodate a 16LP4. That's really stretching a design.

I will have to make new side straps because of moving the bridge back. They're 3/4" too short now. To my surprise, the cross brace still fits.

The raster was shifted to the left. I was able to center it with the horizontal center control, but the raster is out of focus on the right. I had to greatly reduce the focusing field to get it to focus, compared to the 10MP4.

I've included a photo of the dot pattern to show the focus, though it's obvious in the movie photo.

I just noticed that the focusing magnet is pretty far off center vertically. It's centered horizontally. This doesn't seem to match the focus issue.

The yoke is very slightly off axis. It's such a small amount that I can't believe it's the cause. I'll try moving it to see what happens.

The GE data-sheet for a 12LP4 says the center of the focus magnet should be 4-1/2" from the reference line. The Sylvania data-sheet for a 12LP4 says it should be 3-1/4" from the reference line. Mine is 3-1/2" from the reference line. I wonder if I should move it back a bit.

Any suggestions as to what might be causing the left shift and the bad focus on the right would be welcome. It seems to be unaffected by the ion-trap position.

John