Splicing Antenna Wire

Splicing Antenna Wire

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This is a variety of antenna wire splices. All of them are stronger than
steel core wires I use.

The primary problem with steel core wires is water ingress. Water causes the
steel to rust, eventually making the wire fail.

Many wires, in particular fine wires like in stranded copper-steel wires like
Wireman stranded ~450 ohm ladder line (advertised as higher impedance, but
really less than 400 ohms), have very thin flash coatings. Heat from soldering,
or any scraping, will expose the steel core. This will make the wire rapidly
rust. Even without heat, the wire will eventually rust through!

This is also true for steel electric fence wire, which usually has a very
thin cadmium coating.

Copper Sleeve Splice

This is the most attractive splice, and pulls through most insulators. I cut
three inch sections of close-fit copper tubing, and put small pieces of rosin
core solder inside.

I crimp the copper near the center to hold the wire in place, and heat the
copper with a propane torch. I flood more solder into the ends. 

This is a splice after pulling the wire past wire breaking strength.

The advantage of this splice is total sealing of steel ends from moisture.

The disadvantage is obtaining properly sized copper tubing, and having to saw
the tubing to length with a band saw, to avoid closing the tube ends.

Butt Splices

Heavy butt splices are strong enough, if the wires are overlaid through the
splice and the splice is crimped and flooded.   Again to avoid
removing thin wire coatings, apply all heat directly to the splice and flood the
splice. This splice does not seal wire ends, so leave a long overlap.

Modified Western Union Splice

For rapid heatless splicing, a modified Western Union splice works well. It
easily can hold more than the wire breaking strength. The key to this is
twisting the free ends. It can also be soldered by heating, provided the wire is
not overheated in the process, but has always made a very good connection
without solder for me. The key to a good connection is tight twisting and high
tension on the wire.

I clean wires with a rag and automotive scratch removing compound, or burnish
with an ink eraser.

Sharply bend the wires by hand at the starting point of wrap.

Wrap the wires tightly by hand, using the long ends as a lever.

Keep the wire turns butted tightly against each other.

This is a finished wire splice WU or lineman’s wrap.

Although it looks ugly, I added an additional step. This step is critical for
maximum strength. It prevents the wire splice from unwrapping and pulling apart.

This single step will be the difference between a splice failure under severe
mechanical load, and having a splice stronger than the actual wire strength.

If the wires scratch out here, it takes a long time for rust to work through
the splice. The end can be coated with a layer of any type RTV.

This is the splice above, after the wire was tested by pulling until the wire
broke. The splice did not fail, and I have never had one fail in the field. 

Pliers marks are visible on the twisted end. That is a point that would
eventually rust, if not coated.