hi,

what tools or methods do you use to position links above 10 or 20 km long?

I am using a gun scope. I had a bushing made that fits the scope and it slides into the Dish that I am using. It's amazing what a little movement made on the dish shows thru the scope. This gets you pretty close. I am making another adapter for grid dishes that uses the scope also.
Mike

You could try using ydi's calculator to find up and downtilt angles of both sides of the link at the distance and heights you are shooting for.

http://ydi.com/calculation/antenna-downtilt.php

Then use a digital level to get the antenna's positioned at there up or downtilt angles, and move the antenna from left to right till you hit the sweet spot. That is how we do it and seems to work pretty well for us.

Just make sure that you take into account the terrain and make sure you have no fresnel zone echroachement(spelling?)

Dan