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Author Topic: Vertical shift WG K4900  (Read 4351 times)

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MaximRecoil

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Vertical shift WG K4900
« on: August 05, 2006, 03:24:00 pm »
Is there a way to center the picture vertically on this monitor? The monitor has an "H. SHIFT" pot which is used to center the picture horizontally but I can't find a control to center the picture vertically, and the picture on this monitor is off center vertically by at least an inch. 

MaximRecoil

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Re: Vertical shift WG K4900
« Reply #1 on: August 05, 2006, 04:41:17 pm »
I found a manual for this monitor. It is a 3 position jumper :-\. That's some sweet fine-tuning control right there. Thanks Wells-Gardner.

So it is about an 1/8" off center now, and I guess that is as close as it is going to get because WG didn't want to "splurge" for a pot.

I have another question though regarding the horizontal width coil. Which direction (CW or CCW) do you turn the allen-head screw inside to make the picture wider? I have it all the way CC right now, and earlier I turned it maybe 6 or 7 complete turns CCW and it didn't seem to make a noticeable difference in the horizontal width. I didn't want to keep going because I don't know if that allen head screw will turn indefinitely or simply unscrew and fall out, so I turned it all the way back CC and left it. If I could make the horizontal width about a half inch wider, the picture would be close to perfect aside from being vertically off-center by about an eighth of an inch due to that crude 3 position vertical shift  jumper adjustment.

Ken Layton

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Re: Vertical shift WG K4900
« Reply #2 on: August 05, 2006, 11:08:07 pm »
Later production 4900's had a small "vert Position" adjustment board in addition to the 3 position jumper.

For changing the range of the width circuit by changing the width cap value, visit Bob Roberts adjusting widths page.

MaximRecoil

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Re: Vertical shift WG K4900
« Reply #3 on: August 06, 2006, 03:15:30 am »
Later production 4900's had a small "vert Position" adjustment board in addition to the 3 position jumper.

I don't think mine has that, though I'm not sure exactly where to look. Are you talking about a separate board?

Quote
For changing the range of the width circuit by changing the width cap value, visit Bob Roberts adjusting widths page.

Yeah, I have read his page that accompanies his horizontal width cap kits and it looks like it is a trial and error thing with swapping out caps of differing values until you get one that puts you in the right ballpark. That sounds like a long and frustrating day to me...

Turning the adjustment on the width coil doesn't seem to have any effect at all on the picture width -- I wonder if the width coil itself needs to be replaced?

« Last Edit: August 06, 2006, 03:44:14 am by MaximRecoil »

Ken Layton

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Re: Vertical shift WG K4900
« Reply #4 on: August 06, 2006, 07:46:01 pm »
On width coils the farther away the slug is from the center of the coil the wider the picture. Of course this only works to a small extent. In general, the total on-screen adjustment range of the width coil is only 1/4" on each side of the picture

Ken Layton

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Re: Vertical shift WG K4900
« Reply #5 on: August 07, 2006, 11:25:13 am »
The later production 4900's that had a vert position board had the small standup board located between the adjustment pots and the vert position jumper wires. It can be seen in some of the 4900 series manuals you can download from the net.