Okay here is the screw you need to adjust, just above where it says Dual, right near the corner of the top plate.
Click image for larger version. 

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I was unable to upload the manual for your turntable, but you can get it here, you just have to register (it's free). It'll show you a picture of all adjustments on page 4.


http://www.vinylengine.com/library/dual/1019.shtml