After reevaluating the trees in my yard I realized that I could rework the layout of my loop skywire antenna. This would allow me increase the size of the loop, improve the feed point arrangement, and increase the height of the antenna.
After adding a fifth anchor point the loop is now a distorted pentagon instead of trapezoidal in shape (see the sketch for the rough layouts). The new arrangement is not only larger, but also higher than before, which should help its performance. With a new circumference of approximately 244 feet of wire the loop is much closer to resonance on the 80 meter band than it was previously.
Due to the repositioning of the feed point I had to shorten the feedline. I decided on 37 feet of 300 Ohm ladder line as an acceptable non-resonant length for the feedline. This is a good length since it keeps it well off the ground while still providing some slack for movement. So far the performance has been at least as good as the previous version.