[UK-CONTEST] Wire antennas slung over trees

[Steve Knowles]

It's important to keep the wire out of the woodwork, whatever kind of wire you use!  If you don't have to be covert, 16swg hard-drawn copper is the strongest and will stand a lot of tension; use polyprop rope as a support which helps to stop the trees thrashing about too much, if they're not too big - bigger trees can't be tamed so easily so use a nylon support rope to protect the wire.
I have also had success with heavy-gauge plain stranded copper, as used for car loudspeaker wiring, which is also particularly good for downleads not under tension.
I don't recommend Flex-weave.  This stretches, and in consequence twists and untwists badly with changes in tension which can cause problems with tangling.  Also, because the woven structure of the wire forces the RF to cross from strand to strand, the slightest failure of the insulation or of the sealing can lead to corrosion and losses, particularly at higher frequencies.
For getting the halyard up there, a catapult is the simplest to use.  The bigger, the better is a good rule since the heavier the first line, the less the chance of it breaking.  (The largest I have used was a catapult made of two 20' scaffolding poles and powered by multiple strands of 1/4" square elastic, which successfully put half a brick with the halyard tied directly on, over the top of a 100' tree - not in my own garden, unfortunately!)  You can buy a model called the "Wrist Rocket" which will throw a 1oz fishing weight with 20lb line attached, and you can hold the reel in the same hand as the catapult, thus making one-man operation posible.
Whatever colour wire you put up, unless you are lucky enough to live way out in the country, it will get dirty over time and darken down.

Best of luck & 73

Steve
G3UFY