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I have a whole spool of military communications steel wire that I've been thinking about using to string up a doublet. We used this stuff when I was in the 138th Signal Btn and let me tell you, it's the meanest wire for it's size and weight that you'll ever lay your hands on. Some of it's attributes are:

  • It's so stiff that the set coils are hard to straighten out - and it's really tough to wrap around a bolt. Must be spring-steel?

  • It doesn't like to 'take' solder. It doesn't tarnish or rust. (???)

  • The black insulation resists scuffing, abrasion or even stripping.

  • It's so tough that it's very hard to break - or even to cut with wire dykes.

If anything could withstand being stretched 136 feet between trees and coated with ice to last a dozen winters, this should be it. It's 16 guage and hard to see from 50 feet away.

It's surely not nearly as well suited as copper for conductive properties but we used it in the Army for comm wire between field telephones and it's been used as such through World War II. It's really mean to work with - but it's hard to hurt it. Even in the worst conditions it lasts almost forever!

https://www.omahas.com/shop/communications-wire-spool/

Has anybody tried using this wire for an antenna? What'd you think after you got done? Was it worth the grief?

Dax
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  • Is this steel or coper clad steel? If it was meant for communications, I'd guess it's copper clad, and fine for antennas. – user10489 Jul 17 '22 at 12:51
  • Yes, sounds like army comm wire, which is 3 strands steel 4 strands copper or something like that. This stuff is perfect for antennas. – user10489 Jul 17 '22 at 15:19
  • All 7 strands are plated with something that's shiny as chrome and they don't tarnish after years of exposure. Dunno what the resistance per 100' is but it does seem worth a try. It's springy and comes off the reel like concertina wire. – Dax Jul 17 '22 at 15:51
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    Typical anti-corrosion resistance plating is nickel. Difficult but not impossible to solder to. – user10489 Jul 17 '22 at 16:04
  • If you include the part number for your army surplus wire, I will write a more complete answer. – user10489 Jul 17 '22 at 21:30
  • I wish that I could provide a number - which would be an avenue to finding some specifications. I bought the spool of wire that somebody had rewound from the original reel for $5 at a hamfest when everybody was packing up to go home. I'm hoping to find somebody who has already built an antenna from this and hopefully learn if it's a feasible project or just an exercise in futility. Working with it is no easy task. In the Army we used mechanical connections - like a drilled bolt where a nut was screwed down to secure it. – Dax Jul 18 '22 at 00:17
  • I have a spool of the stuff in the club shack, I'll pull the number off mine as an example when I get a chance. – user10489 Jul 18 '22 at 00:29
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    according to the labels on the pictures, that's WD-1A; that's very well-specified. That type name isn't hard to find, it's literally right after the P/N (part/number) on the label... – Marcus Müller Jul 18 '22 at 14:46

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Skin depth resistance on steel wire does bite a bit at low frequencies. Here is my calculation:

This handy calculator says that 60 feet of 16 AWG wire, at 3.5 MHz will have a resistance of about 2.5 ohms if it's copper, and 17 ohms if it's stainless steel. This is about 1/3 of the feedpoint impedance of the dipole, so it will have a neglegible effect on efficiency, less than 1 dB. That's before considering ground losses if the dipole is close to the ground. (I used 60 feet because the current is largest in the centre, and low at the ends, so using the full length wouldn't be appropriate).

Antennas are mechanical beasts first and foremost, and this wire sounds strong, corrosion resistant and hard to see. Most important, you already have a roll of it. If you can handle the challenge of making the connections, this wire sounds great for a dipole.

tomnexus
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  • nice, but this is a seven strand wire with 4 copper and 3 steel strands, and that means that probably none of the high-frequency currents will flow in the steel. The question is what effect the proximity of ferromagnetic material to the surface of the copper, where most of the power transfer happens, does. And I'll be honest: no clue. – Marcus Müller Aug 09 '22 at 14:01
  • Then I hope the copper is on the outside, which would make the ideal antenna wire. The current will flow in the outer few 10s / 100s of microns of the bundle, whatever the material (unless it's braided like Litz wire, unlikely). No fields inside the conductor so the proximity of the steel shouldn't matter. – tomnexus Aug 09 '22 at 14:23
  • yes, but the E-Field would be on the outside of the copper conductor, parallel to it, and the H-Field "circling" around that, and thus, intersecting with the steel conductors. – Marcus Müller Aug 09 '22 at 14:35
  • H is also only outside - fields decay exponentially inside a conductor so very little beyond a skin depth or two. With some caveats for stranded wire, it depends on the layup, but as the wire is thin there should be no circumferential currents. So I suppose the same applies to insulated stranded wire too - they form a good enough cage. – tomnexus Aug 09 '22 at 18:51
  • H should exist as curl around E-field and hence also inside the adjacent (imperfect) conductors. That's why I'm suspecting linear/hysteresis effects! – Marcus Müller Aug 09 '22 at 18:54
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I've used Copper clad steel MIG wire 035 just fine as do others. I think this would be even better so use it with confidence.

KD9UQE CRAIG
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  • I've also used copper plated steel welding rods (TIG filler rods in this case) for antennas, mostly small Yagis. But I think the copper is very very thin, just for corrosion protection. One website says 0.1-0.3 micron, which is less than a skin depth so doesn't reduce its resistance much. – tomnexus Aug 09 '22 at 14:28