I sometimes put the big diamond stone up against the rods of a Sharpmaker and use that as an angle- guide when putting an edge back on a really blunt old thing, or when completely reprofiling. Far from always, but it will work to put a specific edge on and then afterwards you will be able to use the Sharpmaker for tuning if you want. Don't try and re-profile with the Sharpmaker or the Fallkniven, though. You'll be at it for a decade.
You can make a wooden block up too. Get a bit of wood and cut it at the angle you want, then rest an aggressive stone against it and sharpen away, keeping the blade perpendicular to the ground
You can make a wooden block up too. Get a bit of wood and cut it at the angle you want, then rest an aggressive stone against it and sharpen away, keeping the blade perpendicular to the ground