Best wire for long wire antenna
I am getting back to the HF bands after some 20 years 'rest'. What is the
best type of wire to use for long wire antennas? The wire will be under some tension to keep it above some local trees! ----------------------------------------- You have hobbies. I have hobbies. Chances are I have one that you don't. I'll leave it up to you to decide! http://www.flightsimulatorandhobbies.com/ ----------------------------------------- |
Best wire for long wire antenna
"Best" has a number of different definitions depending on the particular
situation. If you want wire that'll never stretch or break and will take a lot of tension, Copperweld is hard to beat. It's springy and a nuisance to work with, though. Roy Lewallen, W7EL JERD wrote: I am getting back to the HF bands after some 20 years 'rest'. What is the best type of wire to use for long wire antennas? The wire will be under some tension to keep it above some local trees! ----------------------------------------- You have hobbies. I have hobbies. Chances are I have one that you don't. I'll leave it up to you to decide! http://www.flightsimulatorandhobbies.com/ ----------------------------------------- |
Best wire for long wire antenna
Since '70, I've had good luck with stranded hard-drawn copper for up to
lambda/2 dipole on 80m (no experience with longer spans). The latest stuff I've been using is 12ga (268 strand) hard-drawn for a single wire 80m dipole and now a cage dipole for 80m using 14ga from Davis RF (http://www.davisrf.com/). They also offer porcelain compression insulators, so a broken insulator won't bring your antenna down (and leave the end of the wire dangling in the trees). Nice folks to deal with, too. Bryan WA7PRC Roy Lewallen wrote: "Best" has a number of different definitions depending on the particular situation. If you want wire that'll never stretch or break and will take a lot of tension, Copperweld is hard to beat. It's springy and a nuisance to work with, though. Roy Lewallen, W7EL JERD wrote: I am getting back to the HF bands after some 20 years 'rest'. What is the best type of wire to use for long wire antennas? The wire will be under some tension to keep it above some local trees! |
Best wire for long wire antenna
Roy Lewallen wrote:
"Best" has a number of different definitions depending on the particular situation. If you want wire that'll never stretch or break and will take a lot of tension, Copperweld is hard to beat. It's springy and a nuisance to work with, though. In this day of high copper prices, my two favorite antenna wires are free wire and cheap wire. We had a fellow near here who, until the past year or so, was selling 500' spools of insulated #14 or #12 for five or six bucks per spool. I ran better than ten spools for my 80 and 160m inverted L's and stocked up for inverted vee wire. A less expensive alternative might be the hardened aluminum fence wire in the larger diameters, allowing for some means of preventing the corrosion from copper to aluminum at the feedpoint. Dave Heil K8MN |
Best wire for long wire antenna
Bob Miller wrote:
Also, I've used the 500' spools at Lowe's Home Improvement; they're in the $30 or $40 range now, I believe. Good grief - last time I bought some for radials they were half that price. -- 73, Cecil http://www.w5dxp.com |
Best wire for long wire antenna
"JERD" wrote in
: I am getting back to the HF bands after some 20 years 'rest'. What is the best type of wire to use for long wire antennas? The wire will be under some tension to keep it above some local trees! You might find the article 'Sufficient sag for wire antenna spans for wind survival' at http://www.vk1od.net/rigging/sag.htm of interest. You might wonder why annealed copper in almost any form (enamelled, or PVC insulated, especially PVC insulated) is so popular. I endorse Roy's support for Copperweld, but you will not find it readily available in Oz. There are a few suppliers of HDC (ATN and Discount Cables come to mind). Stainless steel (2mm dia) is used in some of the commercial antennas (eg Bushcomm), but you need to consider whether the additional loss is an issue for the specific antenna. BTW, MIG wire (copper plated steel wire) is not Copperweld, Copperweld has a substantial copper thickness (eg 30%, depending on the grade) which is chosen to be at least several skin depths in thickess so that the RF resistance is similar to copper, but the strength comes largely from the copper core. Hams promoting 0.8mm MIG wire (as they do here) are on the wrong track, it is a grossly inferior product, you are much better off with galvanised fence wire than MIG wire. Speaking of which, heavy galvanised steel fence wire (say 1.6mm for shorter spans) is not all that poor, but beware of newer fence wires which have thinner zinc, or worse the polymer coated wires with have an extremely thin layer of ZAl covered by the polymer coating. Though any of these are going to be better than rusty MIG wire. Owen |
Best wire for long wire antenna
Owen Duffy wrote:
"JERD" wrote in : I am getting back to the HF bands after some 20 years 'rest'. What is the best type of wire to use for long wire antennas? The wire will be under some tension to keep it above some local trees! You might find the article 'Sufficient sag for wire antenna spans for wind survival' at http://www.vk1od.net/rigging/sag.htm of interest. You might wonder why annealed copper in almost any form (enamelled, or PVC insulated, especially PVC insulated) is so popular. I endorse Roy's support for Copperweld, but you will not find it readily available in Oz. There are a few suppliers of HDC (ATN and Discount Cables come to mind). Stainless steel (2mm dia) is used in some of the commercial antennas (eg Bushcomm), but you need to consider whether the additional loss is an issue for the specific antenna. BTW, MIG wire (copper plated steel wire) is not Copperweld, Copperweld has a substantial copper thickness (eg 30%, depending on the grade) which is chosen to be at least several skin depths in thickess so that the RF resistance is similar to copper, but the strength comes largely from the copper core. I think you mean the strength comes from the steel core? FWIW, when they say 30%, that means that the wire has 30% of the conductivity of the same diameter copper wire, not that it is 30% copper. You have to look in the mfrs tables to see what the cladding thickness is. Odd that there aren't suppliers in Australia.. Maybe because there isn't an existing telegraph/telephone cable infrastructure in rural areas? In the U.S., there were and still are millions of miles of the stuff installed before carrier telephony, coax, optical fibers, etc became common. And, it's still used for MV power distribution, much of which is still above ground. |
Best wire for long wire antenna
Jim Lux wrote in
: Owen Duffy wrote: .... thickess so that the RF resistance is similar to copper, but the strength comes largely from the copper core. I think you mean the strength comes from the steel core? Yes, thanks Jim. FWIW, when they say 30%, that means that the wire has 30% of the conductivity of the same diameter copper wire, not that it is 30% copper. You have to look in the mfrs tables to see what the cladding thickness is. Yes, IIRC it is rated on its 60Hz resistance as a competitor to HDC aerial power applications. Odd that there aren't suppliers in Australia.. Maybe because there isn't an existing telegraph/telephone cable infrastructure in rural areas? In the U.S., there were and still are millions of miles of the stuff installed before carrier telephony, coax, optical fibers, etc became common. And, it's still used for MV power distribution, much of which is still above ground. Yes, pity that. Remember that we had a monopolistic telecomms market until ~1995. I did scavenge a littel copper clad steel (3.2mm) on one occasion, but most aerial phone cables were HDC. My article mentions an aluminium clad HT steel fencewire which looks interesting for antennas, but it does bring the issue of corrosion resistance connection to aluminium. Unfortunately, this wire is only available in 1km rolls. It turns out that HDC is probably the best available wire in Oz (JERD is a VK5), but gal fencewire or stainless steel are eminently suited to lossy antennas like TTFD etc. I do remember Roy discussing the resistivity of rust, but I don't recall figures... does anyone have any figures for the resistivity of the rust coating on a rusted steel wire? I guess its permeability is also relevant to RF resistance. Owen |
Best wire for long wire antenna
Owen Duffy wrote:
. . . I do remember Roy discussing the resistivity of rust, but I don't recall figures... does anyone have any figures for the resistivity of the rust coating on a rusted steel wire? I guess its permeability is also relevant to RF resistance. No, I don't believe I've mentioned rust, although I've commented on copper and silver salts a couple of times. I wouldn't try to guess what the resistivity of rust might be, since it would surely vary a great deal with the amount of hydration. A highly resistive coating won't add appreciable loss, nor will a highly conductive one. There's an in-between range which will. But keep in mind that the skin depth is inversely proportional to the square root of the conductivity, so a thick coating with twice the DC resistivity will increase the RF resistivity only by a factor of about 1.4. The real problem with thinly plated steel wire is that if and when the coating corrodes off -- or if it's too thin to begin with -- the current ends up flowing in the steel itself. Steel is terribly lossy stuff at RF chiefly because of its permeability, not that its conductivity is all that hot to begin with. Skin depth is inversely proportional to the square root of permeability, so a steel with permeability of 100 has 1/10 the skin depth it otherwise would, resulting in 10 times the RF resistance. If you consider half wavelength antennas at various frequencies all made from the same size wire, you find that the loss gets worse as frequency decreases. So it's often more of a problem on the lower frequency bands. Some stainless steels are magnetic and some aren't. Magnetic ones are much lossier at RF for the same reason as ordinary steel. Roy Lewallen, W7EL |
Best wire for long wire antenna
The 'best' wire for long antennas is whatever you happen to have
the most of that will support it's own weight. After that, it's more a matter of what color insulation you think is nice. And after that, it's whatever you can convince yourself that you can afford. Have several pieces of different wire size/type? If they will support their weight, splice the @#$ things! Paint it all pink. Pink works very well for antennas. - 'Doc |
Best wire for long wire antenna
On Fri, 16 Nov 2007 06:49:08 GMT, "JERD"
wrote: I am getting back to the HF bands after some 20 years 'rest'. What is the best type of wire to use for long wire antennas? The wire will be under some tension to keep it above some local trees! ++++++++++ I have had reasonable success with aircraft control wire. Strong and reliable. Here is one source http://www.airsuppliers.com/Aircraft...WIRE_CABLE.htm |
Best wire for long wire antenna
On Nov 16, 2:01 am, Roy Lewallen wrote:
"Best" has a number of different definitions depending on the particular situation. If you want wire that'll never stretch or break and will take a lot of tension, Copperweld is hard to beat. It's springy and a nuisance to work with, though. There are many sources of non-Copperweld-brand stranded copper-clad- steel wires from the ham retailers, e.g. www.therfc.com, www.thewireman.com, etc. It's a joy to use and handles more like aircraft cable than solid springs. Some insist it has to really be Copperweld brand to be good but my standards aren't so high. Besides Copperweld-brand stuff seems to be conspicuously out of stock at all the ham retail shops, and when I inquire about it they tell me that they don't ever expect to get it again. Tim. |
Best wire for long wire antenna
"Tim Shoppa" wrote in message ... Some insist it has to really be Copperweld brand to be good but my standards aren't so high. Besides Copperweld-brand stuff seems to be conspicuously out of stock at all the ham retail shops, and when I inquire about it they tell me that they don't ever expect to get it again. Tim. You should be able to get it he http://thewireman.com/antennap.html I just use what I can find. Usually some # 14 or #12 insulated stranded wire. Mostly free from where I work. When some of the older construction is removed there is lots of wire that would be thrown away that has been in conduit in the building for 10 to 30 years. Once it is up in the air there is no best wire (as long as it is copper) as far as the signal goes. If you could measuer to the tenth of a db, there may be. The main thing is will it stand up to the weather. |
Best wire for long wire antenna
Tim Shoppa wrote:
. . . Some insist it has to really be Copperweld brand to be good but my standards aren't so high. Besides Copperweld-brand stuff seems to be conspicuously out of stock at all the ham retail shops, and when I inquire about it they tell me that they don't ever expect to get it again. My recommendation of Copperweld by brand was made only because it's a known quantity. I'm sure there are other brands which are just as good. But I'll bet there are others with a skimpy copper plating, or cladding that might be thin enough to allow current in the steel, particularly on the lower bands. You need to be more cautious using stranded copper clad steel wire than solid wire. Even though the copper might be equally thick in terms of wire diameter, smaller diameter individual conductor strands mean a thinner coating in absolute terms. The only time I've actually had a problem was with RG-174 sized coax, where the loss was much higher than expected on the lower bands because of the very small center conductor strands, and I think the conductor was genuine Copperweld. But a combination of small strands and less-than-Copperweld thickness might be enough to result in considerable extra loss in some antenna sized wire. The great majority of amateurs wouldn't notice the few dB of extra loss, and in fact are likely to think highly of the extra bandwidth the loss would bring. (One was presented in QST years ago, the author apparently unaware that the secret of the broad bandwidth was the loss of the chosen wire type.) So this phenomenon isn't necessarily bad. But some folks might benefit from knowing about it. Roy Lewallen, W7EL |
Best wire for long wire antenna
Roy Lewallen wrote:
"My recommendation of Copperweld by brand was made only because it is a known quantity." I`ll second that! Copperweld was the only manufacturer or vendor my college allowed to present a tutorial on their product. It was an annual affair. The faculty obviously thought very highly of the product or was impressed by the quality of the meals they bought. I`ve used literally tons of Copperweld wire of many sizes and twists and attest to its durability in antennas and transmission lines. We put it together with Nicopress compression fittings. Best regards, Richard Harrison, KB5WZI |
Best wire for long wire antenna
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