This article documents a weather test on a trial section of two wire line using:
- 1.6mm 5356 Aluminium MIG wire;
- agricultural clips (Trellis Clips, Rose Clips) found on eBAY.
Above is a pic of the Rose Clip as a line insulator / support. The clips are pretty flimsy but pretty cheap. They click onto the 1.6mm diameter wire reasonably firmly.
Above, a small dob of hot melt glue is used to fix the clip at one end only so that it does not move along the line. The other side is clicked on but free to move to accommodate twists and turns. The clips will probably be needed at intervals of 0.5m or perhaps less in some situations.
The short test section has been in the weather for two years, but has not been subjected to a real trial as a long section of line in all weather.
Above is a calculation of expected performance. The velocity factor is a guess based on experience.
Essentially, though it is very low cost, it achieves Zo around 480Ω with matched line loss around 0.23dB/100m @ 3.5MHz. The clips cost about $6/100 and the wire about $0.07/m, so all up $0.26/m.
Above is a mockup of a dipole leg terminated on an insulator, and the feed line connected using the 3mm stainless steel tap connector. In use, the tap connector will be filled with marine grease or aluminium jointing compound to exclude oxygen and water.
Above is a 2mm stainless connector. The 1.6mm wire has to be bent to follow the path through this smaller connector body. Again it needs to be filled with grease to exclude oxygen and water. These connectors are available on eBay at low cost.