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I am building a zs6bkw dipole using a ladder-lock. For mechanical strength, I am looping the 12 gauge wire, as in the image below, and swaging it. The next step is to join the thick antenna wire to the smaller ladder-line wire on the ladder-lock. The connection doesn't have to be mega-mechanically strong, since the antenna wire is swaged, so I am trying to find the best, electrically conductive way to splice these two wires together.

ideas:

  1. Strip the ends of both wires about an inch, fan-out the stranded conductors, merge the two fanned out ends, twist them together, and solder the wires together.

  2. Strip the ends of both wires about an inch, wrap the thinner wire around the thicker wire, and solder the wires together.

  3. Strip the ends of both wires for a Solder-Loaded, Heat-Shrink Reducing, Crimp-On Butt Splice (image below; meant to join wires of different thicknesses). For example: https://www.mcmaster.com/crimp-on-wire-connectors/solder-loaded-heat-shrink-reducing-crimp-on-butt-splices/.

The first option didn't work well because the individual strands in the 12 gauge wire were too strong and wouldn't twist well together with the strands of the ladder-line wire.

The second option worked, and the solder joint does not appear to be "cold", but I would be surprised to find that the two wires are optimally joined.

The third option is very appealing, but I could not find anything when I googled about using such a joint for a dipole antenna and whether it would seriously degrade performance (increased resistance/reactance, etc.).

I'd really appreciate your comments about the third option, since it is the one that is most appealing to me.

Thank you for your time and interest,

Mike

Swagged wire

enter image description here

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  • $\begingroup$ Is the 12 gage wire made of steel or copper? Do you scrape off the black coating first? $\endgroup$
    – tomnexus
    Commented Jan 25, 2023 at 23:09
  • $\begingroup$ Hello, both wires are copper and I have stripped off the coating. I have ordered the butt-splice that I mentioned and should be able to test things tomorrow. Since the wires are connected together by the solder between them, I expect that this will be a very good connection w/o increased resistance/reactance. I will post what I learn. $\endgroup$ Commented Jan 26, 2023 at 5:19

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If both wires are copper, then all three solutions you mention will work fine electrically.
If you solder it, use flux and make sure the thicker wire gets hot enough. Place the iron only against the thick wire, until the solder flows in the joint.

Like all things in antennas, your main concern should be mechanical. How much residual twisting and movement is there in the heavy copper wire? Will this break the thin transmission line wires? Solder makes it worse. The solder/shrink splice looks nicest because it might transfer some stress to the insulation of the copper wire.

Try to prevent water from wicking down into the insulated stranded wire, it will corrode it inside and perhaps reduce its RF performance. Glue-lined heatshrink is probably the best you can do, nothing will actually stick to the wire. If you know how it will be mounted, maybe you can position the wire joint so it is out of direct rain, under a hat or cover.


Having looked at some ladder-lock devices now, I can say (forgive me)
enter image description here

The last picture looks best to me, because it keeps the insulated wire intact, all the way through the potential bending zone, and then attaches it firmly to the antenna wire. I'd even add a cable tie around the insulated portion to keep it from bending the copper at all.

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