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MS8 to MS9 swap convergence issues (Toshiba tube)

idiosync

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I picked up a recapped/serviced MS9 to replace the MS8 that was originally in my Toshiba A68kJU96X tube'd Astro recently, partially to pre-emptively replace the MS8 (that I'm pretty sure was never serviced), partially to take advantage of the MS9's updated design, and partially to mess with the 31khz/sharpness mod. Initially after installing the MS9 (before I replaced the yoke) it looked about as good as I could have asked after some color calibration, but I was having issues with width and needed to pump the B+ a bit to fill 15khz. I took the time at this point to do the sharpness mod as well as the 31khz mod and both were successful, but 31khz wasn't anywhere near filling the screen. Since I was already this far in and was having trouble filling the screen in 15khz anyway, I decided to bin the original yoke, convergence rings and homemade adapter and go with the yoke/rings that came with the MS9 which from my understanding would help fix the filling issue. I wanted to avoid it if I could, but the urge to mess with it more overcame me.

I adjusted the B+ back to the recommended values, and now width looks much better with the "new" yoke. Convergence was all out of whack, so I began the task of messing with the rings and after a bit, I was able to get the center to look pretty close to where I want it to be. Unfortunately, it almost looks like the green grid is vertically larger than the magenta (which I was able to lock down pretty well) and I can't get them to align anywhere except the dead center of the screen. Anyone have any tips? I tried messing with some magnets, but that only seems to affect the corners, not the center top/bottom. The attached photo shows what I'm talking about.

IMG_20240528_155417 (Large).jpg
 
Found yoke resistance measurements online. Measuring between the red/blue horizontal connector got .6, vertical brown/gray I got 8. First time I've done this on a yoke, so I'm not sure if I did it 100% correct, but it looks like that might be off compared to the Rh 0.7ohm Rv 9.3ohm listed on https://wiki.arcadeotaku.com/w/Yoke_Specifications. Am I heading in the right direction with this? Could this be caused by an out of spec yoke? Some of the copper on the outer side does look a little corroded. I'm mainly heading this way because convergence is great when using the MS8 yoke and adapter.
 

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Where did you get that yoke from?

Are you sure it's not from a Hitachi tube?

Hitachi and Toshiba are different shaped tubes and the yokes won't play nice with each other.
 
Where did you get that yoke from?

Are you sure it's not from a Hitachi tube?

Hitachi and Toshiba are different shaped tubes and the yokes won't play nice with each other.

Thanks for taking a look, I got it from davesarcades along with the chassis. Is there any way to easily tell?
 
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