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Antenna Support Rope
I have in my yard two 60 foot steel poles about 120 feet apart, placed there
40 years ago by a previous ham owner. The old halyards, about 3/4 inch diameter cotton-covered wire (wire core was about 1/8 inch) are long gone, and I need to find new rope to haul up my wire. I can't find anything like the old stuff. I was thinking about using wire rope, the flexible 7x19 kind, maybe stainless steel, at maybe 3/8 inch diameter. I think that will roll over the pulleys (which I think are less than 1 inch radius). Given that my longest wire will have maybe 8-10 feet of poly lines supporting each end, will wire rope present appreciably more metal at the ends than the poles themselves will? Is there a synthetic rope up to the task? Keep in mind that the rope I need will be running vertically, and when the antenna load is placed perpendicularly, the loads on the halyard will be in the several hundred- to thousand-pound load range. Of course it needs to last for decades or more in the sun. As always, if you have suggestions that haven't occurred to me I'll gladly listen to them. -- Bruce Wilson KF7K http://science.uvsc.edu/wilson |
Antenna Support Rope
"Bruce Wilson" wrote in
: I have in my yard two 60 foot steel poles about 120 feet apart, placed there 40 years ago by a previous ham owner. The old halyards, about 3/4 inch diameter cotton-covered wire (wire core was about 1/8 inch) are long gone, and I need to find new rope to haul up my wire. I can't find anything like the old stuff. I was thinking about using wire rope, the flexible 7x19 kind, maybe stainless steel, at maybe 3/8 inch diameter. I think that will roll over the pulleys (which I think are less than 1 inch radius). Given that my longest wire will have maybe 8-10 feet of poly lines supporting each end, will wire rope present appreciably more metal at the ends than the poles themselves will? Is there a synthetic rope up to the task? Keep in mind that the rope I need will be running vertically, and when the antenna load is placed perpendicularly, the loads on the halyard will be in the several hundred- to thousand-pound load range. Of course it needs to last for decades or more in the sun. As always, if you have suggestions that haven't occurred to me I'll gladly listen to them. What the blazes are you planning to pull up there? A Sterba for 15 meters or something? -- Dave Oldridge+ ICQ 1800667 |
Antenna Support Rope
Ham Radio Outlet, HRO, sells a Black Nylon Antenna Rope that will do just fine.
www.hamradio.com - - - Bruce Wilson wrote: I have in my yard two 60 foot steel poles about 120 feet apart, placed there 40 years ago by a previous ham owner. The old halyards, about 3/4 inch diameter cotton-covered wire (wire core was about 1/8 inch) are long gone, and I need to find new rope to haul up my wire. I can't find anything like the old stuff. I was thinking about using wire rope, the flexible 7x19 kind, maybe stainless steel, at maybe 3/8 inch diameter. I think that will roll over the pulleys (which I think are less than 1 inch radius). Given that my longest wire will have maybe 8-10 feet of poly lines supporting each end, will wire rope present appreciably more metal at the ends than the poles themselves will? Is there a synthetic rope up to the task? Keep in mind that the rope I need will be running vertically, and when the antenna load is placed perpendicularly, the loads on the halyard will be in the several hundred- to thousand-pound load range. Of course it needs to last for decades or more in the sun. As always, if you have suggestions that haven't occurred to me I'll gladly listen to them. |
Antenna Support Rope
I am using a couple thousand feet of the black braided dacron form
DAVIS RF for some ten years now... Still looks like new...' denny |
Antenna Support Rope
For antenna wire, cables, and ropes, I usually start with Radioworks. You'll find an excellent selection of antenna lines and ropes for whatever application you want at: http://radioworks.com/PDFCat05/70-71.pdf Ed K7AAT |
Antenna Support Rope
"Bruce Wilson" wrote in message . .. I have in my yard two 60 foot steel poles about 120 feet apart, placed there 40 years ago by a previous ham owner. The old halyards, about 3/4 inch diameter cotton-covered wire (wire core was about 1/8 inch) are long gone, and I need to find new rope to haul up my wire. I can't find anything like the old stuff. I was thinking about using wire rope, the flexible 7x19 kind, maybe stainless steel, at maybe 3/8 inch diameter. I think that will roll over the pulleys (which I think are less than 1 inch radius). Given that my longest wire will have maybe 8-10 feet of poly lines supporting each end, will wire rope present appreciably more metal at the ends than the poles themselves will? Is there a synthetic rope up to the task? Keep in mind that the rope I need will be running vertically, and when the antenna load is placed perpendicularly, the loads on the halyard will be in the several hundred- to thousand-pound load range. Of course it needs to last for decades or more in the sun. As always, if you have suggestions that haven't occurred to me I'll gladly listen to them. -- Bruce Wilson KF7K http://science.uvsc.edu/wilson I am using two lengths of 3/16 th black Dacron covered rope from CableXperts, or maybe Texas Towers. It has been holding up 280 feet of 75 meter loop ( #14 wire) for at least 6 years. (It makes a 90 degree bend at 75 feet). I once used 3/8 inch Poly something rope. It rotted so badly that after 6 months I could pull it apart between my two hands. BTW, you can do a LOT worse than plastic covered clothesline; after all, it is meant for outdoor use. Tam/WB2TT |
Antenna Support Rope
Tam/WB2TT wrote:
. . . I once used 3/8 inch Poly something rope. It rotted so badly that after 6 months I could pull it apart between my two hands. . . That would have been polypropylene, widely sold in hardware and DIY stores. It rots in no time if exposed to UV. Polyester holds up very well, and nylon is just about as good. (I think most of the rope sold specifically for antenna use is polyester.) I'd use black rope if I lived in an area having a lot of direct sunlight and/or one that's at at high elevation, since this improves its UV resistance, but ordinary nylon or polyester rope lasts many years at my western Oregon QTH. (Maybe the moss/algae growth helps.) I like nylon because its stretchiness acts as a shock absorber, but this would be a disadvantage for some applications. Roy Lewallen |
Antenna Support Rope
"Roy Lewallen" wrote in message
... That would have been polypropylene, widely sold in hardware and DIY stores. It rots in no time if exposed to UV. Polyester holds up very well, and nylon is just about as good. (I think most of the rope sold specifically for antenna use is polyester.) I'd use black rope if I lived in an area having a lot of direct sunlight and/or one that's at at high elevation, since this improves its UV resistance, but ordinary nylon or polyester rope lasts many years at my western Oregon QTH. (Maybe the moss/algae growth helps.) I like nylon because its stretchiness acts as a shock absorber, but this would be a disadvantage for some applications. Roy Lewallen Polyester (Dacron) rope has the higher ultraviolet resistance. Nylon, especially if formulated with UV absorbers and anti-oxidants does fairly well too. If you get acid rain in your area, Nylon will not last nearly as long. Polyethylene and polypropylene ropes are rapidly destroyed in sunlight. The mechanism that protects polyester from ultraviolet in sunlight is an interesting one. When a short wavelength photon hits the polymer in the rope, its energy has to go somewhere. Often it just heats the polymer, but sometimes it breaks the polymer chain. Polyolefin ropes (polypropylene and polyethylene) have an easily broken polymer backbone. The backbone is much stronger in polyamides (Nylon). Polyesters, however, have aromatic (benzene-like) structures in them that absorb the short wavelength UV radiation and re-emit it as longer wavelength fluorescence. In polyethylene terephthalate (PET, Dacron) this fluorescence is generally in the near infrared so it is not visible. In polyethylene naphthalate (PEN), the fluorescence is in the visible region. This polyester has better barrier properties for food use and can withstand slightly higher temperatures than the PET used in most plastic soft drink bottles and food containers. But the fluorescence is unwanted in most food applications so quenching agents are added to suppress this property. Dacron is DuPont's proprietary name for their PET. Usually rope sellers charge a premium for the name, but polyester fibers as used in ropes are manufactured by many other companies. Roy is correct about the black rope lasting longer. Carbon black added to the polyester is an excellent UV absorber. 73, Barry WA4VZQ Remove the NO SPAM to reply directly. |
Antenna Support Rope
On Thu, 17 Aug 2006 01:33:58 -0400, "Graywolf"
wrote: Polyethylene and polypropylene ropes are rapidly destroyed in sunlight. Barry, There is a type of rope known here as Silver Rope. I understand that it is manufactured from UV stabilised polyethylene and claims resistance to sunlight. It is also claimed to be resistance to most acids and alkalis. It is a very low cost rope, white in colour, and is widely used in marine applications. I have halyards and tails of this stuff that have been in the weather for 10 years with no significant degradation (superficially or observed when the strands are opened up). Silver Rope is about half the price of Dacron rope (though only about 80% of the strength of Dacron). It takes knots well (as well as the better synthetic fibre ropes, it has a slightly greasy feel), good abrasion resistance and it is easy to splice. Owen -- |
Antenna Support Rope
"Owen Duffy" wrote in message ... On Thu, 17 Aug 2006 01:33:58 -0400, "Graywolf" wrote: Polyethylene and polypropylene ropes are rapidly destroyed in sunlight. Barry, There is a type of rope known here as Silver Rope. I understand that it is manufactured from UV stabilised polyethylene and claims resistance to sunlight. It is also claimed to be resistance to most acids and alkalis. It is a very low cost rope, white in colour, and is widely used in marine applications. I have halyards and tails of this stuff that have been in the weather for 10 years with no significant degradation (superficially or observed when the strands are opened up). Silver Rope is about half the price of Dacron rope (though only about 80% of the strength of Dacron). It takes knots well (as well as the better synthetic fibre ropes, it has a slightly greasy feel), good abrasion resistance and it is easy to splice. Owen -- If you live anywhere near water, a boat shop might be a good source for rope that will withstand weather and UV. Think of all the rope on a sail boat. I haven't checked prices. Tam/WB2TT |
Antenna Support Rope
On Thu, 17 Aug 2006 08:25:28 GMT, Owen Duffy wrote:
On Thu, 17 Aug 2006 01:33:58 -0400, "Graywolf" wrote: Polyethylene and polypropylene ropes are rapidly destroyed in sunlight. Barry, The Wireman is another excellent source of antenna rope. Contact him at TheWireman.com. Walt, W2DU |
Antenna Support Rope
Excellent comparison. I'll abandon the wire rope idea and get some black
Dacron or polyester. Thanks to all for your comments! -- Bruce Wilson KF7K http://science.uvsc.edu/wilson "Graywolf" wrote in message ... "Roy Lewallen" wrote in message ... That would have been polypropylene, widely sold in hardware and DIY stores. It rots in no time if exposed to UV. Polyester holds up very well, and nylon is just about as good. (I think most of the rope sold specifically for antenna use is polyester.) I'd use black rope if I lived in an area having a lot of direct sunlight and/or one that's at at high elevation, since this improves its UV resistance, but ordinary nylon or polyester rope lasts many years at my western Oregon QTH. (Maybe the moss/algae growth helps.) I like nylon because its stretchiness acts as a shock absorber, but this would be a disadvantage for some applications. Roy Lewallen Polyester (Dacron) rope has the higher ultraviolet resistance. Nylon, especially if formulated with UV absorbers and anti-oxidants does fairly well too. If you get acid rain in your area, Nylon will not last nearly as long. Polyethylene and polypropylene ropes are rapidly destroyed in sunlight. The mechanism that protects polyester from ultraviolet in sunlight is an interesting one. When a short wavelength photon hits the polymer in the rope, its energy has to go somewhere. Often it just heats the polymer, but sometimes it breaks the polymer chain. Polyolefin ropes (polypropylene and polyethylene) have an easily broken polymer backbone. The backbone is much stronger in polyamides (Nylon). Polyesters, however, have aromatic (benzene-like) structures in them that absorb the short wavelength UV radiation and re-emit it as longer wavelength fluorescence. In polyethylene terephthalate (PET, Dacron) this fluorescence is generally in the near infrared so it is not visible. In polyethylene naphthalate (PEN), the fluorescence is in the visible region. This polyester has better barrier properties for food use and can withstand slightly higher temperatures than the PET used in most plastic soft drink bottles and food containers. But the fluorescence is unwanted in most food applications so quenching agents are added to suppress this property. Dacron is DuPont's proprietary name for their PET. Usually rope sellers charge a premium for the name, but polyester fibers as used in ropes are manufactured by many other companies. Roy is correct about the black rope lasting longer. Carbon black added to the polyester is an excellent UV absorber. 73, Barry WA4VZQ Remove the NO SPAM to reply directly. |
Antenna Support Rope
On Thu, 17 Aug 2006 08:03:20 -0600, "Bruce Wilson"
wrote: Excellent comparison. I'll abandon the wire rope idea and get some black Dacron or polyester. Thanks to all for your comments! The Wireman has uv-resistant Dacron rope. bob k5qwg |
Antenna Support Rope
Tam/WB2TT wrote:
If you live anywhere near water, a boat shop might be a good source for rope that will withstand weather and UV. Think of all the rope on a sail boat. I haven't checked prices. Ironically, polypropylene rope, the very worst kind for UV, is often sold as water ski tow rope and for other marine applications, because it floats. So check the label carefully. A friend of mine once built an 80 meter vertical from PVC pipe, with a wire inside or outside of it. Being an analytical sort of person, he carefully calculated the wind loading, allowing for the 100+ MPH winds not uncommon in his area of Colorado. Then he selected guy rope of the required strength, with a hefty safety margin. It worked fine for about 6 months, then the antenna fell over on a day when there was only a slight breeze. Mystified, he inspected the antenna and found that he could pull the rope apart with his bare hands. That was when he, and I, learned about polypropylene rope and sunlight. Of course, his location at about a mile elevation and where the sky is clear 300 or so days per year was a particularly harsh environment for plastic as well as for fair-skinned people. I got away with using the stuff for a couple of years here in western Oregon. But there are a lot better choices. Roy Lewallen, W7EL |
Antenna Support Rope
Welcome back to the group, Barry. I, and I know many others, really
appreciate hearing the straight story from someone who truly knows what he's talking about. Thanks! Roy Lewallen, W7EL Graywolf wrote: Polyester (Dacron) rope has the higher ultraviolet resistance. Nylon, especially if formulated with UV absorbers and anti-oxidants does fairly well too. If you get acid rain in your area, Nylon will not last nearly as long. Polyethylene and polypropylene ropes are rapidly destroyed in sunlight. . . . |
Antenna Support Rope
Roy Lewallen wrote:
Welcome back to the group, Barry. I, and I know many others, really appreciate hearing the straight story from someone who truly knows what he's talking about. Thanks! Speaking of someone who truly knows what he is talking about Roy, here's a technical question for you. Given that a mobile antenna stinger has a VF of approximately 1.0 so we can determine the approximate number of degrees that it occupies and ... Given that we can use EZNEC to determine the feedpoint impedance of that stinger, it seems to follow that ... We should be able to use a Smith Chart to determine the characteristic impedance (Z0) of that stinger. Yes, no? -- 73, Cecil http://www.qsl.net/w5dxp |
Antenna Support Rope
Bruce Wilson wrote: Of course it needs to last for decades or more in the sun. Like Roy says... good luck... Better be some really UV resistant stuff if you want it to last decades. As always, if you have suggestions that haven't occurred to me I'll gladly listen to them. Myself, I use antenna support *wire*. And that will last for decades. But another reason I do that, is often I lengthen the antenna wires for other bands. Fer instance, at the moment I'm using an 80 meter turnstile, which are crossed dipoles, and also a 40 meter dipole, all fed parallel with one coax. But two of the 80m wires can be doubled to act as a 160m dipole, and also I have a set of jumpers to use it for 20m. So by just changing the locations of the insulators, I can change things around according to season. I can have the present setup, or I can have 80,40,20, or I can have 160,80,40. The latter is the usual "winter" mode. My wires including the support wires are so strong they will crumple the top section of mast before the wire breaks. I had that happen when a large tree branch fell on a leg in an ice storm. The wire didn't break. But it bent the top mast section over, and I had to replace it. That was cheap though, as I use an extra top mast section which is not part of the actual telescoping mast. Sure, fresh rope is just as good, but it won't last as long as the wire. Mine is insulated also, so that helps to prevent corrosion. I don't see why it wouldn't work in a pully as long as it didn't kink up on you. MK |
Antenna Support Rope
"Graywolf" wrote in message
... I used to work in the research laboratories of Eastman Chemical Company. Eastman made PET, PEN, PETG (glycol-modified PET, used in microwave/conventional oven dinners), as well as polyethylene and polypropylene. Some of their liquid crystal polymers would make excellent, very high-strength rope, but the cost would be rather prohibitive for most hams. 73, Barry WA4VZQ I believe that Dacron is actually PET. At least that's what I read at Wikipedia. -- Bruce Wilson KF7K http://science.uvsc.edu/wilson |
Antenna Support Rope
"Bruce Wilson" wrote in message
. .. I believe that Dacron is actually PET. At least that's what I read at Wikipedia. Dacron was originally PET fiber made by DuPont. It was their registered trade name, but.is now owned by Invista. When Eastman Chemical Company was still part of Kodak and still manufactured PET fibers, its trade name was Kodel. Polyester fibers are made by a number of companies, each with their own tradename. When referenced as rope, polyethylene terephthalate is usually implied. However, other thermo-softening polyesters, such as polybutylene terephthalate end polyethylene nalhthalate, are available. Thermo-setting polyester resins, too, are found. These are commonly used in fiberglass boats and some printed circuit boards although most printed circuits use epoxy resins. Quoting from the Invista website(www.invista.com): "INVISTA is independently managed but wholly owned by a subsidiary of Koch Industries, Inc. On April 30, 2004, subsidiaries of Koch Industries, Inc. acquired INVISTA from E. I. du Pont de Nemours and Company. INVISTA, formerly DuPont Textiles and Interiors (DTI), was merged with KoSa, a producer of commodity and specialty polyester fibers, polymers and intermediates. KoSa had been a Koch affiliate since 1998." 73, Barry WA4VZQ |
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