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I have now delved further.
Disassembling the yoke-focus coil stack on my #1 version of this Philco revealed an extra layer of nuts between the yoke and the magnets - based on what I found in the #2 set. That changed the presumably critical spacing between the yoke and the focus coil bolted on behind it. That extra nut shifted the focus coil's position over the gun by about 3/16 inch aft. Now, having "corrected" that, to duplicate the spacing found in my #2 set and having assembled the magnets from #1 with the yoke from #2, I find that the focus from the original situation appears to have changed slightly – now it’s 100% perfect at the extreme CW end of its focus control rotation. But it should be around the mid-point of the control rotation, as with magnet #2, and that still leads me to think that the permanent magnet from #1 is not up to snuff. So, on the one hand, I've got sharp scanning lines! On the other hand, no headroom in the focus control.
There are some contradictions to clear up. I will delve yet further.
Roger
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