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Spyswitch00
New Member



86 Posts		 Posted - 20 Jun 2003 :  16:37:47
Hello everyone!

I'm tweeking the Mac Plus with the adjustment rehostats on the left side.

Now I've seen one for voltage -why anyone would want to vary that is beyond me.

There is another one for focus
one for contrast (since brightness is on the front of the computer, right?)

there is another one for vertical expansion and contraction.

and one for horizontal expansion and contraction.

the one I'm looking for is the one that shifts the image left and right. I'm guessing, there isn't one and I have to be stuck with the larger margin of black than on the left.

Is this normal, or is there some secret left/right tweak that I don't know about?

thanks for reading and your patience.

spyswitch
tomlee59
Starting Member


USA
46 Posts		 Posted - 02 Jul 2003 :  14:38:27
There's no electrical centering adjustment. Look on the neck of the crt. Right by the screw that tightens the yoke is a pair of rings with tabs sticking out. Those are the centering adjustments. Rotate them until the raster is centered the way you like it.

I recommend doing this with one hand in the pocket. Alternatively, use an insulating tool (old tootbrush, chopsticks, etc.). The danger of shock is low, but it never hurts to be careful.

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redrouteone
Junior Member


USA
226 Posts		 Posted - 20 Jul 2003 :  22:33:47
The voltage adjustment will change the voltage that the flyback transformer puts out. Adjusting this will adjust the focus of the monitor.

--Eric
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tomlee59
Starting Member


USA
46 Posts		 Posted - 23 Jul 2003 :  17:26:57
Um, yes, adjusting the voltage *may* affect the focus, but that's hardly the reason why the voltage adjustment pot is there. There's a separate focus adjustment, after all, and adjusting the global voltage to adjust the focus makes no sense.

The reason for the voltage adjustment is very simple: When they manufactured these things, they were not able to guarantee that blind assembly would result in the correct voltages. So, they included this adjustment so that, before shipping to the customer, the voltage would be adjusted. Then, you're supposed to leave it alone from then on, unless you make some circuit changes/replace stuff, etc.

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