Radials: buried electric fence aluminum wire
The local Tractor supply has 1/4 mile spools of 14 gauge electric fence wire. My son is renting a wire
trencher next weekend to put in his electric dog fence. Soooo, I'm thinking we'll split the rental and I'll
bury about 20 or so radials for my planned 160 meter inverted L.
How long will aluminum wire last in damp New England soil before electrolysis eats it up? If I can get
20 years out of it, it will probably outlast me!
Probably less than 6 months before it is gone!
Aluminum and soil just do not mix!
A while back, a local (Richardson, Texas) amateur radio operator very carefully put in 60 buried radials under his HyTower. For a couple of months the antenna worked great. Then, the performance started dropping off. After about 6 months he went out and "tugged" on one of the radials. He had less than 6 inches of wire in his hand! It was the same for all the rest of the radials. That is, less than a foot of wire remained.
If you want radials to last, you pretty much have to use copper. Galvanized steel fence wire will last a little while before rusting away, but it isn't worth the trouble to put them in the ground for a permanent installation. Putting aluminum in the ground is both a waste of money, effort, and good aluminum.
Loads of the electric fence wire here now has stainless steel conductors. That would be better.
Think of it K3LR and 6Y1V.
Best contest stations in the world?
What do they use?
Proud Antenna User
Depending on the soil you might get 12 months or two years from alloy wire , I suggest you consider stainless or copper
Originally Posted by K1ZJH
I have some electrical THNN 14 and 16 gauge wire that I will try using.
Don't bury your THHN very deep, if at all. I'm guessing that a "wire trencher" will bury your radials far too deep.
There is no advantage to burying radials 1" deep vs. stapling them to the surface of the earth. Radial staples are the way to go. The radials will all but disappear into the grass in a few months.
Do yourself a favor and follow the links to N6LF's excellent info on ground systems at http://www.w0btu.com/Optimum_number_...al_length.html.
I agree. Aluminum may last 6 months, Around here in 12 months it will be turning to white powder. Dont do it!
Commercial AM broadcast stations used 10 gauge soft drawn bare copper wire. A good compromise for ham use seems to be something like 14 gauge copper wire. And as pointed out, You want it close to the surface, NOT buried deep. When I use the stuff from the local discount home supply store, I roll it out and tie it off between trees so it is easy to work with and take a handy knife and strip the insulation off. BARE copper wire will be adding to your DC/Lightning protection ground system in addition to providing the RF ground.
(The "invisible" dog fence wire should also be buried close to the surface, Or simply stapled down as mentioned.) The only places I buried my own invisible fence wire is across the driveway and where it runs across the lawns. In the woods/rough areas I simply laid the wire on the ground and put sticks on it to keep wildlife from tripping on it. In a few years it all "self" buried and can no longer be seen at all.) An ideal trencher for installing either could be a lawn edger type tool. Not a big trench machine as used to install power wires deep........
Last edited by K9KJM; 08-14-2011 at 05:47 AM.
As Mike said use radial staples you can buy them on eBay cheaper than anywhere from a ham. All you do is mow the grass short in the area where you want them to be one time. Lay out the wires and push in the staples with your thumb they are about 2" or so long with a big V on top to push it in with. The next time you mow that part of the yard just a little higher and in a few weeks you will never see it again I have 64 on the ground stapled for my veritcal no problems in 4 years with wife mowing.
73 de Fred N0AZZ
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A lot depends upon the aluminum alloy. Ive had bare aluminum CATV hardline running on the ground in a constantly damp pine and oak forest (and loaded with blueberries and huckleberries) for over 22 years and there is absolutely no corrosion. Its the same on the tower or arial runs where its been exposed to acid rain and salt laden fog for just as long.