Posted: 6/7/2011 8:22:00 AM EDT
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I get email sale ads from a company that sells electric fence and other farm fence products. This week's ad had some electric fence twine that has steel and COPPER strands. Steel for strength, the copper for low resistance. AND it is UV resistant. It comes on 1300'+ rolls for just $44 plus shipping.
So, will this work for antennas? It does for electric fences. I suppose it depends on how much copper, etc. How good a connection can be made? Crimp on ring terminals? etc. So, they are sending me a few feet as a sample. This may or may not be a good material for antenna wire, long dipoles, windoms, field expedient antennas, but I'll get the sample and find out. I'll report my findings here. |
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If it's what I'm thinking, where it's very thin wires braided into a rope or twine, I think I would avoid that for antenna use. If for no other reason than the rope will hold water and change the dielectric constant, so the length of the antenna would seem to change quite a bit between wet and dry.
I have used aluminum electric fence wire for wire antennas with success over the years. |
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This stuff reminds me of the Army's DR-8 commo wire. Has a mix of steel and copper strands. Stuff is hella strong, used it for everything from tying stuff down to lashing things together. And on occasion even used it for connecting communications equipment. One great use for the stuff is for a weed whacker wire. Cut a piece to the length you need and you never have to worry about breaking lines again every time you hit a rock.
As for how effective it can be for an antenna: Only way to really know is to try. The differences in conductivity between the steel and copper wire may not be great enough to be noticeable in the application. |
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Quoted:
If it's what I'm thinking, where it's very thin wires braided into a rope or twine, I think I would avoid that for antenna use. If for no other reason than the rope will hold water and change the dielectric constant, so the length of the antenna would seem to change quite a bit between wet and dry. I have used aluminum electric fence wire for wire antennas with success over the years. OK, I'm missing something- why would the dielectric constant of something that doesn't totally surround the conductor, or occupy a significant part of the distance between the conductor and ground matter? I'm skeptical because the twine may add to the windload without increasing strength. If the stuff has enough tensile strength, I'g give it a try. To terminate try rubbing the end with noalox and sticking it in a 6 or 4 AWG long barrel compression terminal (availbale at an electrical supply) and flattening the terminal barell in a vise. I've had to look at the tensile strength vs wind load for some HF antennas I put up in south florida. The largest copperweld I could find was 14 awg, and I knew the wire like likely to get hit by wind blown debris, so I ended up using bronze wire rope from McMaster Carr with philystrand and springs on the end. They all survived Katrina. I should mention the wire was over 100' long |
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Quoted:
So, will this work for antennas? It does for electric fences. I suppose it depends on how much copper, etc. How good a connection can be made? Crimp on ring terminals? etc. Also depends on how much transmit power you're running. There will be I2R losses at spots on the antenna where the impedance is low and the current is not... |
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Quoted:
Quoted:
If it's what I'm thinking, where it's very thin wires braided into a rope or twine, I think I would avoid that for antenna use. If for no other reason than the rope will hold water and change the dielectric constant, so the length of the antenna would seem to change quite a bit between wet and dry. I have used aluminum electric fence wire for wire antennas with success over the years. OK, I'm missing something- why would the dielectric constant of something that doesn't totally surround the conductor, or occupy a significant part of the distance between the conductor and ground matter? I'm skeptical because the twine may add to the windload without increasing strength. If the stuff has enough tensile strength, I'g give it a try. To terminate try rubbing the end with noalox and sticking it in a 6 or 4 AWG long barrel compression terminal (availbale at an electrical supply) and flattening the terminal barell in a vise. I've had to look at the tensile strength vs wind load for some HF antennas I put up in south florida. The largest copperweld I could find was 14 awg, and I knew the wire like likely to get hit by wind blown debris, so I ended up using bronze wire rope from McMaster Carr with philystrand and springs on the end. They all survived Katrina. I should mention the wire was over 100' long "OK, I'm missing something- why would the dielectric constant of something that doesn't totally surround the conductor, or occupy a significant part of the distance between the conductor and ground matter?" I don't think you are missing anything, there's no 'counterpoise', if I can make the crude analogy, for the non-metalic component be a factor. Sounds like there's a very good chance it will work fine, considering the I2R limitation Ski mentions on higher power. |
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See if it might be this. This use to be very common when making large antenna arrays. http://www.acasolutions.com/products/copperweld_alumoweld/ |
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If this is the stuff I think it is, it should work. I'm thinking it's the stuff like the poly hay-twine that also has wire strands in it. How well it will radiate...I'd think you'd just have to try it. That poly hay-twine is STRONG stuff. If this is similar and actually radiates....I'll be getting a spool for emergency back up. |
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I have not posted a link because I don't want all you guys ordering a spool and then finding out it does not work, and you are all ticked off at me for it.
I have samples coming. When I told them what I was thinking of Lori wrote back and said she would gladly and immediately send me a few feed as a sample. She also asked a few very good questions about ham radio. I told her about upcoming Field Day, what that was all about, and she wants to visit a club Field Day event near her. Hey, what can I say? Am I selling this hobby or what? 
Let me get this stuff in, see just how it is made, THEN I'll spend MY money on a spool and give it a test drive. When I get it in, see what I want to know about it, I'll post a photo and link. Then I'll order some ($45 for 1320') plus shipping. That's a quarter mile, how long top fuel dragsters used to race, two furlongs, 4.4 football fields. That's a halfwave of 350 khz. |