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Scan lines on monitor question

VodkaGobalsky

VodkaGobalsky

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I noticed one of my MS8-28 monitors is producing thicker scan lines than my other one. How can I dial down the amount of scan lines showing up on the monitor? Or is it dependent on the tube? I believe the chassis are the same.
 
I belive there's a VLIN pot that you can adjust. Should be on the side of the chassis.
 
VLIN is vertical linearity. This corrects for symmetry on the vertical image (are all boxes on cross hatch same height).

For the scanlines themselves, try increasing the brightness pot on the remote board and lowering the contrast. MS8 is a sharper chassis than an MS9, so you will see the scanlines appearing to be heavier by that fact alone. Not much you can do about it.
 
Adjust focus on the flyback. There's two pots, it's the top one.

Put up a grid from a test menu. You'll see how it works.
 
The ms8 29 is just sharper than lots of chassis including ms9, this is only an advantage in picture quality! the flyback mounted on the ms8 is just stronger when come in focus, you can set the focus by the trimmer on the flyback itself.
 
The MS8 is sharper than the MS9 because G1 is referenced to negative instead of being referenced to ground, this means the difference between G1 and G2 is bigger, which means the beam is tighter, so the spots are smalle , so the edges are sharper. This is interesting in a minute even tho we aren't discussing MS9's here

But, you can fiddle with the G1 voltage on an MS9 to make it sharper like an MS8 by referencing G1 to -ve as described here
https://www.arcade-projects.com/threads/nanao-ms9-29-enhancement-hacks.15995/

And you can use this principle to fiddle with the sharpness of any monitor (we'll talk about Trinatron another time) by adjusting the difference between G1 and G2 voltages as described here
https://shmups.system11.org/viewtopic.php?t=67124

Changing (and even measuring) G1 voltage is a bit of a hairy proposition on an MS8 because the MS8 chassis is partially hot and is most definitely not safe. Probing it directly without proper precautions will destroy your gear as described here
View: https://www.youtube.com/watch?v=xaELqAo4kkQ


So if we cant mess with (or even safely measure) G1 voltage maybe we could mess with the other side of the equation and adjust G2 voltage instead? Its the difference between the two that makes the monitor look sharp or soft. One of the knobs on the flyback directly sets G2 voltage, twiddling that would fix the sharpness...

...but as a side effect of messing with the Focus pot of the flyback it will mess with colour/brightness/black levels - so follow these instructions to fix https://shmups.system11.org/viewtopic.php?t=67477

A lot of this is is actually quite hard on an MS8 because its hard to accurately measure anything without blowing something else up. I'm seeing why people love the MS9...
 
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