Updated: 2026-08-26
My main antenna is a delta shaped SLOUS (sky loop of unusual size). It is strung between three very large trees spaced far apart. One is a sturdy white pine, the other two very ancient (and somewhat decrepit) black cherry trees. Each side of the triangle spans a gap of approximately 46m at an average 12m elevation. To minimize sag, ballast weights are quite heavy.
Being located just 2 km inland of storm-tossed Lake Michigan, all three trees are subject to gale force winds. Several times, either one black cherry tree or the other has shed heavy branches from higher up to snag on the wire. Ease of repair is my highest priority.
Trees sway. The higher the limb, the greater the sway. Each span of the antenna wire thus requires a long draw cord, pulley, and weight at one end. I rig those ends using rope spliced into Q (loop with pigtail).
Under heavy tension, stranded wire presents a significant torque for strongly wanting to undo the continuous twist of its own strands.
Many a dipole has been cut to exacting measure, then mysteriously grew longer for having partially self-untwisted under tension.
When the Giant Coat Hanger was needing its first ever repair, immediately I found myself confronting this effect. In lowering one corner, no sooner was there very much slack before the rope, egg, and both wire legs wrapped themselves around one another. A coworker could have helped me deal with the problem; but I was working alone. Re-rigging all three corners put paid to it happening ever again.
How it works: Each 1/4-inch (6mm) OD fiberglass rod serves as a rigid pendulum. With gravity pulling it down, un-twisting torque from multi-strand wire under tension does not suffice to raise the rod more than 1/4 turn (from 6 o’clock to 3 o’clock).
Supply: Such rods are sold in hardware stores for use as driveway markers. A 4-foot (50 cm) length cut in half makes for two pendulums. File one end of each piece into a gradual taper. Force the tapered end into the insulator egg at the wire-side hole. Fix in-place using weatherproof tape.
My particular sky loop has a geometry problem. This stems from its history of plural prior versions: LINK
Glossing over that part, know that the tree serving as its feed-point is an ancient black cherry sprouting from three large boles. Its canopy is widely spreading. The sky loop’s two ends cannot be made to meet conveniently. How to circumvent such a daunting obstacle?
Easily, as turns out. The solution is to feed upwards from near the ground. The antenna’s two ends angle downward as a vertical V toward a feed-point near ground level. Credit for this idea is owed to David Ring, NE1A, a retired maritime radio officer who informed that it was common enough on cargo ships for their MF antennas once upon a long time ago.
Detailed breakdown for the freshly minted ham. There exist any number of ways to get that very first line into some high fork in a tree. Here are the lessons which I learned by trial and error.
Fishing sinkers are the obvious choice for a weight. Shop on-line for perfectly spherical 1.5 to 2 ounce ‘bullet’ or ‘cannon ball’ sinkers: LINK . Local stores will most likely carry only teardrop shaped weights. And while a 1-ounce teardrop flies straight and true, it is very prone to overshoot. The geometry of heavier teardrops is more long than fat. This makes them prone to flip into a tight spin, traveling only a very short distance. Sinkers heavier than 2 ounces require heavy-duty (black) elastic slingshot straps as opposed to ordinary yellow ones.
A tuft of fluorescent pink fly-tying fluff crammed through the eye allows for easy tracking in flight.
The most frequent problem is overshooting. The weight might fly straight and true directly through the aimed at fork, then much further still through yet other branches. I have two trees each decorated with plural snagged weights trailing lengths of fishing line. In the future I might try splicing short, 3-lbs test leaders onto the end of the reel’s heavier test fishing line. Thus to serve by way of an easily broken ‘fuse’ for post-snag sinker retrieval.
Bought from Amazon, this consists of a weighted sack with metal ring. That tied with a single half hitch to a whole lot of line draped loosely into a square, foldout, canvas box. Packing easily into a suitcase, I have twice taken it overseas.
Makes for easy and accurate tossing. Just swing in a circle and let go. If the weight snags, just pull hard on the line. The half hitch will come undone; weight and line both fall to ground.
Sometimes I’ll climb partway up a step ladder. This affords a bigger circle of swing. The swing can thereby be slower, and the release less critical. Other times from atop the roof of my house.
The throw weight and line can also be used to snag a high wire that you’re wanting to haul down. Allow the weight fall to ground; then haul on both lines.
Trees grow. Left too long, bark will encompass your rope at the fork. Each spring and fall, haul on the rope a foot each direction to break it free from any adhesion. I use polypropylene rope. While not resistant to UV, for being slippery polypropylene sticks less and breaks free easily. I also like 3-strand rope so that I might splice rather than knot them. A spliced loop never snags. Also, splices are pretty, especially after threading through an egg insulator. Plus you can join a leftover length onto a new length for zero waste.
My first set of ropes suspending the Giant Coat Hanger lasted ten years before all but completely degrading. Those were 3/8-inch, white, and very limp owing to the strands being comprised of a great many tiny fibers. I had got two spools cheaply from ULINE on a company discount.
Now retired several years, I have since replaced them with yellow 1/4-inch polypropylene got instead from Tractor Supply. Once again I choose the spliceable 3-strand variety. These are some stiffer owing to the strands’ fibers being of fewer and coarser. Which might well last somewhat longer on that account.
Henceforth I’ll keep a much closer eye against any fraying, especially after five years will have passed. Replacing a still-intact loop is simple and easy as there is no need to re-shoot the fork.
I read once of someone using a U-shaped tube as a protected, easy-slide guide through which to pass paracord over a branch. I have not tried this. Each time when I considered it, the particular tree fork in question seemed an unlikely candidate for getting one up so very high. Plus I cannot help but envision insects building a nest inside, as seems always to happen whenever I might leave an uncapped hose laying out for longer than just only a day.
At least for my main antenna, I much prefer insulated as opposed to bare. The reason is noise. Where I live, in winter we get lots of snow. A little known fact is that each individual snowflake drifting down onto a bare copper wire imparts a tiny static charge. Thus during a snow storm, insulated antennas are audibly quieter than bare copper.
Which begs the question: might bare aluminum be considered ‘insulated’ on account of its oxide coating, at least against snowflakes?
I favor multi-strand over solid wire. In theory it ought perform some better for RF owing to skin effect (more strands = more surface area). With a total length in excess of 100m, how can even a small advantage not help? Many strands also makes the wire limp, drawing out straight under less tension. And being limp, it less prone to break or jam if run through a pulley.
Speaking of pulleys, I go with large diameter clothesline pulleys made of plastic. For the wire, anyhow. Not always the rope.
Grows on buildings and trees. Very pretty! But for some of us it might as well be poison ivy. Seriously! Guess how I found out? Full story here: LINK
