Thanks - but still, how do you attach to the top and bottom - anyway you could post a pic?
Babsbags' ratchet straps, if like the ones I have, have a hook on each end. If not, they have a hook on one end and a loop preformed on the other. It's just a matter of running the strap around each end of the device that's clamped to the fence and hooking the strap back into itself.
There's a dozen or more ways to do it, and none are reallly 'wrong'. I used chains back when I was stretching hog wire, but straps are probably easier.
Here's one video, that kinda shows it:
This guy uses 2 comealongs, which works well tho a little awkward, but it does allow the installer to make adjustments for differences in grade deviations.
This one uses rope. Problem with rope is low breaking point and rope generally has a lot of stretch to it and then there's the problem of getting the knots untied afte you're done.
There are tools you can buy or make that just hook into a bar run thru the fence--I tried one on some welded wire fencing around my garden and did not like them--they elongated the rectangles because there was too much stress applied to just a few parts of the height of the fence. Might work ok on short runs of knotted wire fencing tho.