I won't undress to bare with you, but will try to help.

The brake cable runs from a fixed place in the lever, to a pinch bolt on the brake where the rough adjust is made. Then the adjustment is fine tuned using the threaded barrel adjuster.

Since cable run includes a number of fittings along the way it's important that the housing is properly seated in each or your adjustment will change as it settles.

Start by tying your brakes closed against the rim with a piece of string. Make sure the shoes are in position and hitting the rim squarely, (or slightly toed, in) if not fix this first. Bring the adjuster(s) (on brake or lever or both) all the way in, then back one out a turn or two. (less than 1/8").

Loosen the pinch bolt and pull the wire through until it tight but not with any degree of tension. Tighten the bolt firm enough to hold there, but not truly tight. Remove the string and let the brake open. It should ease away from the rims slightly. If so go ahead and tighten the pinch bolt, and test the adjustment by using the lever. If it's close, fine tune it with the barrel adjuster. If you need more than a few turns of the adjuster to tighten, you might want to try again, pulling the cable down tighter on the pinch bolt.

That should do it.