Yep, and making sure that the clamp stayed attached to the wire was a trick. Always had to get the wire hauled a bit tighter than needed because you knew you'd lose some tension between the stretcher and the post onto which you were tying the wire.
Those were even more fun with woven wire fences like hog wire. I made a clamp out of a couple of 1 x 4's to get reasonably even tension among all of the strands.
+--------------------------------------------------------------------------------+ If you're gonna be dumb, you better be tough +--------------------------------------------------------------------------------+