Hi Doug, the lens of your scope will focus at a given distance behind the lens and that's where you position the eyepiece to achieve focus. When you put a binoviewer in the diagonal you're extending the light path by 4 or 5 inches so the scope's objective lens is focusing inside the body of your bino. To push the objective focal point out to the bino eyepiece holders you can use the corrector/barlow supplied with the bino. If that doesn't push the focal point out far enough you can use a 2x barlow lens instead which gives something like 3.5x magnification. 20mm eyepieces with your scope and a barlow is still only going to give a little over 100x, so you won't have a problem with mag being too high for the objects you'll be looking at.
If the barlow still didn't allow you to achieve focus you might need to use a 1.25 diagonal. Another possibility that I haven't tried would be to unscrew the lens from a 2 inch GSO 2x barlow and screw it onto the front of your GSO diagonal. I use one of the chinese bino's (stellarvue) with my ed100 and they work with both the supplied corrector or a 2x barlow. I hope there's some useful info there for you.
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