Copperweld wire

[N4NYY]

I am just about to order this wire for a trap dipole I am building (20-40-80). Should I go with 10, 12, or 14ga ? I am not familiar with this wire and will be my first purchase of it. I will have pulleys and weights on the ends.

Oh. I am only running 100 watts on it, and have given up on the amplifier idea after the QST and safety defeat article.

[W5DC]

Copperweld wire is very springy and can produce major tangles if its not handled properly.  I grew up on a farm and handled steel bailing wire and knew what to expect when I installed my current antenna two years ago.

Dunc, W5DC

[KG6WOU]

Wow.  Ah, look at the breaking strength.  14 ga copperweld is really tough.  I use 14 ga hard drawn copper stranded and it's still strong enough for an 80 meter.

You need to handle it to avoid kinking - I think you can pull it between two clamped wood blocks and get some of the set out of it that way.

There is also stranded copperweld, 14 gauge - that might suit you better.

[N4NYY]

OK. I understand its flaws.

I see that Davis RF also has a Poly-stealth. I may look at that.

[WA8UEG]

I use copper clad for my low band quad, a bit of over kill for a dipole but I would suggest 14 guage.

[NH7O]

I have three 330' runs of #14 copperweld out, and it is strong and springy as the others say. Keep it on the reel, and try not to allow slack. Extra hands help.

The concern I have is with the thickness of the plating. Skin effect increases with frequency, so the percentage of your RF that flows in the lossy steel increases on 80m and especially 160m. I would be curious to know what the wire plating thickness is.

[AD4U]

It does not matter whether you use 10ga copperweld or 14ga copperweld even at 1500 watts.  The antenna radiation performance will be the same. 

Well........some purists may argue that the 10ga will have minutely more bandwidth than the 14ga due to its slightly larger diameter, but that is about "it".

From my experience with copperweld it can be hard to work with (springy) as already posted.  That being said I would use the smaller gauge unless the extra physical strength of the larger gauge is needed.

Also as far as antenna performance is concerned at RF, copperweld radiates just as well as solid copper.

Dick  AD4U

[N4NYY]

OK. After digging, the Poly-stealth is the stranded version. It appears I will use this. It is 13 gauge.

[K7KBN]

For anyone using Copperweld® wire:  you need to be very careful not to bend it sharply.  If it's too tight a bend, the copper coating will (not "might") crack through, exposing the steel center.  The result? Rust and breaking within a short time.  I took exquisite care when building my 5-band quad; it lasted about 8 years before the elements started breaking, one by one.

IF I restring it, I'll use #14 hard-drawn copper.

[WA8UEG]

Won't affect the performance one way or the other. With copper clad I keep it on the reel and attach the end it to something that won't move then reel out the required amount of wire plus a few feet, pull it tight and let it stay that way for a while. It makes it a bit easier to work with. I just use 14 THHN for 80 & 160 meter dipoles and have never had any problems at all. The copper clad won't stretch so it is ideal for quads as it helps strengthen the spreaders and keeps the spreaders from drooping with heavy ice.

[WA8UEG]

Pat,

I can see where that could be a problem. On mine I run the wire straight from spreader to spreader with insulators as the termination at the spreaders then I jump around the insulators to the next "leg" with a short piece of wire.

[N4NYY]

Why is kinking such a problem. If this wire on small spools?

[WA8UEG]

The conductor is steel, it almost acts like spring steel. You can pull it straight but it will go right back to the form of what ever size spool it was on. Like I said you can "train" it by pulling it straight with tension and leaving it that way for a while. Even then it will tend to coil back up. In the right application it is worth the effort, it is strong and won't stretch. Like he said you also need to careful about nicking it or it will start to rust where it was nicked. As far as a well radiating dipole it doesn't make a hill of beans worth of difference if it's copper weld, THHN, stranded, whatever. Any 14 guage wire will work well. Like I mentioned I have a 80 meter extended zepp (approx length as a full size 160 meter dipole) and 14 guage THHN works fine. I do have a provision to pull the ends tight when needed. I only needed to tighten it up due to stretching 2 or 3 times in the past 6 years.

[WB6BYU]

Copperweld® is a great choice where strength is required, such as using an inverted vee wires
to guy a tower or mast, or a long span of wire that requires sufficient tension to keep it from
sagging.

Note that Copperweld® wire is described as "copper-clad", not "copper-plated".  It is about
30% copper.  Many hams mistake it for copper-plated welding wire instead, which has only a
very thin layer of copper which can corrode off quickly.

Steel is a relatively poor conductor for RF due to the hysteresis losses in magnetic materials.
With a thick enough copper layer this isn't a problem, but it needs to be considered on the
lower bands (especially 80m and 160m), or when the wire diameter is smaller so the copper
is thinner:  the deeper the skin depth compared to the thickness of the copper, the higher
the loss.  This probably isn't a problem with a trap dipole even on 160m because the radiation
resistance is rather high, but it is measurable with shortened antennas having a low radiation
resistance, and especially for ladder line when feeding a low impedance load (like a 80m doublet
fed on 160m.)

Stranded Copperweld® is a particular problem in this regard because each individual strand
has a copper coating - that means that the copper thickness is less than for a solid wire
of the same gauge, and losses are higher on the lower bands.


So for antennas around the yard I use stranded copper, but when asked to design an
antenna between two buildings across a parking lot, I specified solid Copperweld® for strength.

[N4NYY]

I am glad I asked. This was a hell of an informative group of responses.