WG25k7191 Horiz size coil adjustment.

[SoooPig]

My screens are slightly too wide.  Reading up on the monitor, I found the Horiz Size Coil that takes a hex wrench to adjust.  I moved it back and forth and did not see any change in the width of my screen.  This monitor is from a 1993 MKII game.

Should I do a cap kit  or change out the adjustment coil? (or both)?

[JoeB]

Oh.. you got the right coil alright.. but unlike a regular pot, it needs A LOT of movement to notice a difference.

Turn it around a few times, and then you'll start noticing it.

[SoooPig]

OK, I'll try it again.. Clockwise or Counterclockwise to make the screen smaller?

[OSCAR]

Check this out for some good info:
http://www.dameon.net/BBBB/wc.html

Sometimes I've found the width coil isn't enough to adjust the width of the screen, and then I make fine adjustments to the B+ voltage pot.

[Ken Layton]

It usually takes several turns of the width coil before you notice anything. Typically the range of the width coil narrows or widens the picture about 3/8" on each side. If you need more range then you have now, you'll need to change to a different value of the width capacitor. Bob Roberts now has a "width cap" kit with the different values you need to change the width range.

To narrow the picture, turn the width coil (a.k.a. "Horiz. Size") clockwise. If the coil is real hard to turn, use the heat from a hair dryer to soften the wax/glue inside it.

[SoooPig]

Thanks everyone... I moved it 5-7 turns clockwise and saw no change, I guess I try the B+ pot and the cap route.

[Ken Layton]

On your monitor main pc board capacitor # C38 is the width range capacitor. As shipped from the factory the value is .39 microfarad at 200 volt polypropylene. Try one value up or down from your existing value. So you would want to use either a .33 or .47 capacitor. C38 is easy to find on the board---it's right directly to the right of the width coil.