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Author Topic: Your favorite antenna wire.  (Read 43976 times)
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N6YW
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« on: July 19, 2011, 03:14:09 PM »

I am looking around at the various wires available for building the new antenna system here @N6YW.
Because I have this  Elm Tree in the yard, I am going to have to use insulated wire in case the wires come into contact with the limbs...or will I? I had a loop up here once, built from #10 AWG THHN. It arced frequently right through the insulation onto a limb. However, that was likely due to it being a loop. The new antenna should clear the upper canopy because of the 40' Military fiberglass poles being used this time.
What do you like and how well has it worked? The wires on the Wireman site look reasonable and because I live next to the ocean, and run high power all of the time, my choices are narrowed somewhat.
Billy N6YW
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« Reply #1 on: July 19, 2011, 03:40:04 PM »

I think living near the ocean would call for using insulated wire. But then copper clad would turn a nice old buzzard green faster out there. All of my antennas are just plain copper wire. No steel no nothing. My 160 meter an is just # 10 insulated. I pre-stretched it with my pick up truck. If you try to remove the insulation it's very hard as the insulation has somehow been pulled into the wire. It's been up there for eight years now atop two pines at about 80 feet and rising. If you don't have any stress on the wire, plain copper should work fine.
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« Reply #2 on: July 19, 2011, 05:21:20 PM »

The Flexweave 12 AWG stuff looks like the ticket for me, because it is easy to deal with and doesn't have a mind of it's own. I will be using a slingshot to shoot the pull line over the top of the tree.
When the wire gets pulled up, I can't afford to have tangle issues. This tree is such a PIA.
Hopefully by the time the antenna has been up for a couple of years we might have already sold the house and moved to the country. I really need 5 acres  Cool
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« Reply #3 on: July 19, 2011, 06:14:41 PM »

I use #8 Copper clad steel just because I have a large roll of it. Main antenna is # 10 copper clad steel (ex-railway telegraph line) because I had plenty of that when I put up the antenna. The stuff is stiff and hard to work with, but once up, it is indestructible. I would recommend it for tree antenna installation because the tree limb will probably break before the wire does, if you have good insulators that won't fail.

I also use it for open wire line, but my OWL is kept under tension with turnbuckles. I wouldn't recommend it for that purpose unless you can keep it under tension, since it wants to spring back into a coil if left to dangle on its own.
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« Reply #4 on: July 19, 2011, 06:33:38 PM »

#8 solid copper or #10 for smaller antennas. Flex weave will rot sooner.
Every copperweld I ever used was junk. A flash of copper lasted one season before I could see rust.  My beach primary is solid copper. There is a Western Union splice that is older than I am feeding the pole pig that powers the house.
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« Reply #5 on: July 19, 2011, 07:43:52 PM »

In that case, I should be buzzardly and put up the big stuff. It will match my neighbor's roof, green copper.
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« Reply #6 on: July 19, 2011, 07:44:04 PM »

#12 or #14 THHN.
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« Reply #7 on: July 19, 2011, 07:47:36 PM »

Billy,

With copper wire, in general, the finer the strand, the faster it will rot.   A fine stranded Flexweave will rot much sooner than say, a stranded #10 composed of (12) #24 strands.

A solid piece of #8 copper will last forever.  It's all about how hard it is to break down the diameter used. For example, a small .008" of corrosion depth on each fine strand of Flexweave makes a huge difference when all the strands are counted. However,  .008" of corrosion on a 3/16" diameter solid wire has virtually no effect.

TimTron has up a dipole made of solid #8? copper wire.  I remember seeing it at his RockPort location (near salt water) in the early 70's. It was blue. He still uses it today and is strong.

Here I use #10 THHN stranded with the PVC covering. Some of this stuff has been up for 20 years and is still bright inside.  I have my dipoles supported at the centers, so no problem with stretching.

As Frank said, be careful of the plating depth on copperweld. I, too, have used the cheap stuff and had it rust through within a few years. Once it breaks down the thin copper coating, the steel will rust and break quickly.  I would axe the manufacturer about the copper coating depth and compare this to commercial standards to better evaluate.

BTW, the big elm tree - how about taking advantage of it? Climb as high as you can and slide a pole up the tree trunk farther and lash it off. Use a pulley and then center support the inverted vee, etc. (Or maybe you are already doing this)

Yes, your antena wire may arc to the tree, depending on the voltage/impedance point. With a 1/2 wave dipole, the ends are the hottest. For multiple bands/openwire, there may be hots spots anywhere on the dipole depending on the freq being used. Keep it clear of the limbs since you are running QRO.

T
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« Reply #8 on: July 19, 2011, 08:47:11 PM »

Thanks T.
I get that. I am thinking if the ends of the Flexweave were sealed in epoxy, how is the wire going to rot so quickly? I guess if the jacket is porous enough or breaks down quickly in the elements that would be the case, but even a polyethylene jacket can last at least 7 years in the sun and rain, salt air.
The chemicals in certain sheathing materials react in an adverse manner when subjected to different environments. I know this to be true from experience, especially in older types of sheathing from the 50's. Some of that stuff gets rather nasty.
Anyway, The pole idea is a good one and I have thought about that many times. This is an area where my Ham Licensed Wife might disagree though. Everything is a balancing act right?
If I finish painting the house, then she might agree hahahahahahaha!
Thanks guys!
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« Reply #9 on: July 19, 2011, 09:06:57 PM »

OK Billy -

Yep, a pole slid up a  tree is really an effective way to get a high antenna without a tower.  Back in the 70's I slid some telescoping mast up a 50' tree and had an inverted vee at 70' at the apex fed with OWL. The mast sat on a limb at 40' and went up another 30'+ higher, towering over the tree. It may have been more like 80' high now that I think of it.  The dipole ends were pulled way out high into both neighbor's yard trees. Man, did that work well on 75M AM back in its day when a dipole at 30'-40' was the norm. TimTron stopped by and said it was the highest AMer antenna he had seen so far... Grin

OK on the Flexweave. I was talking about the bare Flex, not the jacketed stuff. I'll bet the Flexweave will be FB with the jacket and will last a long time, just like the jacketed THHN.

BTW, on the high mast - use the pulley rope as one back-stay. The dipole legs will help too. Tie a knot in the rope to act as a stop when the inv vee is at the top. Add two ropes to make it a tri-guyed mast.  With some work you can usually pull out the guy ropes and pull up the inv vee clear of the limbs. You may find that sawing a strategic limb will open up a clear area for the antenna work.

Good luck wid it, OM.

T

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« Reply #10 on: July 19, 2011, 09:14:34 PM »

When I had the cloud burner up, I wove 14ga stranded THHHN through all kinds of limbs with a wrist rocket. I never had any issues. As a matter of fact, I'm using a section of that same aerial for my dipole, (the lay of the land/trees don't lend too well for a loop).
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« Reply #11 on: July 19, 2011, 09:30:56 PM »

what you use depends on how much money you want to spend, the physical conditions, what's available and your location.    In a town, or any place where you can't completely control the area all around your antenna, I'd go with insulated wire.  If bare and it breaks for some reason and comes down on someone or somehow starts a fire while you are on the air you don't need that.  Also it makes some sense if you have a lot of antennas near each other like I do.  I had a bare wire dipole once and didn't realize it was swinging into a TV antenna I had up.  No damage fortunately and insulated wire isn't a fix for that, just extra protection.  Admittedly this all may be far fetched in your case so the insulation may be more for piece of mind.  If I were out in the country and I had complete control of the space all around my antennas for hundreds of feet, I'd get rid of any trees in the way, put up one or more towers, and have all bare wire because insulation adds weight.  

The span of the antenna and the wx it usually has to contend with are factors.  You don't have to worry about wind and ice and you probably don't have room for a long span.  this means you can probably get away with a wire that might otherwise stretch or break.  But, this does not necessarily mean you should go with something light weight.  I use no. 12 stranded house wire I got at Home Depot (mine has green insulation--I had some idea it might look better  Roll Eyes ) but my longest span is around 45 feet.   You may have to find a balance between gauge, weight and tension.   You have to sort of experiment.   Every support should have a marine pulley on it with the antenna rope going through the pulleys so you can hoist them up and down and alter the tension.  Too heavy gauge, weight and tension may mean your supports will pull over, especially in a wind storm.   Your end supports and any support that holds a bend have to be strong.  If you give the wire slack to relieve the supports, you may have too much sag and swing in the wind.   Think of the worst wx you have ever had at your QTH and put up your antenna with that in mind.  A common noob mistake is putting up an antenna on a nice calm summer day and it's on the ground with the first bad wx.  
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« Reply #12 on: July 19, 2011, 10:38:32 PM »

@K5UJ
My first antennas were erected in Lake Tahoe 20 years ago. I learned that lesson the easy and hard way. It was easy in that I had 70' pine trees to support any antenna that I could dream of but the hard part was that 90 mph Winter storms that would rip down the Echo Summit bringing Gale force conditions and blowing snow which always resulted in iced over and ultimately, broken antennas.
My TH6DXX tribander lost it's truss cable during a storm and the icing broke the boom in half!
Anyway, all of your contributions are greatly appreciated. The rigging part is easy and I think I am going to take a closer look at the middle pole that was suggested. That would put my feed point up near the 60' ft. level which would rock big time. I think that would be enough to prevent the proximity of the Faraday Cage homes next to me causing so much grief. Now that my neighbors are on Dish Network, I no longer have to contend with TVI issues.
I will try the 12 AWG stranded wire first and see how it plays. My poles are fiberglass, so no problems there. I think the 60' ft. folded dipole with OWL is what I am going to try first.
It looks compact and lightweight enough for the site here. I am going to be creative out of
necessity. I'll share my findings with you all, and of course photos. Of course I ask the girls in my
Avatar to pose with the antenna before it goes up  Grin
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« Reply #13 on: July 20, 2011, 12:45:32 AM »

Every copperweld I ever used was junk. A flash of copper lasted one season before I could see rust.

You must have used copper clad electric fence wire. That stuff isn't worth bringing home. A microscopically thin layer of copper deposited on the surface of a steel wire. Kind of like "zinc plated" vs. hot-dip galvanised hardware.

Real copperweld is clad with copper that makes up 20-30% of the total diameter of the wire.  I used #10 copperweld for ground radials for a 160m inverted-L back in the 70s. Occasionally I still dig up a piece and the copper cladding is intact except for greenish corrosion crud on the surface.  I have filed and scraped it to see how much of the copper was still there, and most of it was.

The worst coperweld I ever had was some that I  bought from Radio Shack in the early 70s. I used it to make the end-fed Zepp I used when I operated from Cambridge.  The stuff kept stretching like pure soft-drawn copper, and the extra length would eventually be enough affect the settings for resonance with the antenna tuner.
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« Reply #14 on: July 20, 2011, 08:31:04 AM »

The old maritime/marine radio intallations often used hard drawn BRONZE wire .
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« Reply #15 on: July 20, 2011, 10:23:03 AM »

A popular wire for the old time multi-wire flat-tops and cage antennas in the 1920s was stranded phosphor bronze. The remnants of the wire antennas at the Marconi station on Cape Cod (now a museum) are made of solid wire that appears to be copper, though it could be phosphor bronze.

Phosphor bronze wire is still manufactured, but it isn't cheap.

I never had much luck using stranded copper wire for antennas.  It tends to eventually break wherever it flexes at terminations, from the wire swinging in the wind.  Solid wire is more durable. Soft-drawn copper tends to stretch and increase in length, although it can be converted to hard-drawn by pre-stretching the wire before building the antenna.
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« Reply #16 on: July 20, 2011, 11:14:11 AM »

Quote
I never had much luck using stranded copper wire for antennas.  It tends to eventually break wherever it flexes at terminations, from the wire swinging in the wind.  Solid wire is more durable. Soft-drawn copper tends to stretch and increase in length, although it can be converted to hard-drawn by pre-stretching the wire before building the antenna.


Interesting. I've found solid wire more prone to break from flexing when the junction was mechanically too tight, unable to move around. A good example is when openwire gets soldered directly to a stress point.   The problem is probably the way the splices/terminations are done...

Splices should always be floating with no strain. Do this by looping all wires thru the insulators and securing. Then the free floating wire ends get joined/soldered.  This way there is never any pull or flexing on a soldered joint.  Using a wide, loose, big loop to secure the wire to the insulator eliminates the leverage that will break a wire that is tightly secured to an insulator.

As for stranded wire, if it is supported at the center with no feedline weight, stretching should be minimal. It is designed to handle flex better. I've had #10 stranded THHN up for many years for the 260' parasitic loop quads. This is strong stuff. The tuning is critical for the DX window and I would see any departure in terms of changed f-b or swr.  I tuned them with beacons so they are critical. These parameters have stayed firm over the years despite ice storms and winds.  Again, it's all in the way they are supported. My quads are pulled out to form a square with maybe 20 pounds of pull on each side.   Of course, a dipole stretched out from each end with no center support is a different story and may need solid wire or copperweld. Still, I have 75M dipoles that use stranded #10 THHN supported with 60' spans that have survived ice and winds FB.

T
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« Reply #17 on: July 20, 2011, 11:21:21 AM »

I agree with Don about Copperweld which is a trade name, the junk is simply copper flashed as with welding wire or single pass plated at about .010".

Rural telephone wire is still available in #10 and 12 with .030" plating and a black nearly impervious jacket. If its going to be swinging in the wind terminate with a couple of guywire clamps and bent around a thimble. Use regular stranded wire as jumpers to the coax connector or solder lugs.

Flexweave is considered unreliable junk by the many DXers and contesters who jumped on it early.

Its pretty hard to beat 7 strand hard drawn copper in most enviroments, I have some here thats been recycled for about 45 years from 5 QTH's.

Carl

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« Reply #18 on: July 20, 2011, 11:38:18 AM »

My favorite antenna wire is the free kind..   Gov't surplus from the dump...


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« Reply #19 on: July 20, 2011, 11:49:56 AM »

The TimTron showed me the way to strip insulated copper clad wire.

The thing to do is to heat the insulation before you strip it. If you don't, you'll end up removing some of the copper weld and expose the steel. In a few years, the antenna will break.
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« Reply #20 on: July 20, 2011, 12:02:59 PM »

Rural telephone wire is still available in #10 and 12 with .030" plating and a black nearly impervious jacket. If its going to be swinging in the wind terminate with a couple of guywire clamps and bent around a thimble. Use regular stranded wire as jumpers to the coax connector or solder lugs.

My #10 is old railway telegraph line.  Most of the rural open wire telephone lines used steel wire, in many cases almost all rust by the time they replaced those lines with enclosed cable. The rail companies used copperweld because it resisted corrosion from the sulphur-laden smoke spewed out by the old steam locomotives. Steel, even zinc-plated, wouldn't have lasted more than a couple of years in that environment, but the copper jacket was highly resistant. When I got mine, it had a nice hard green patina but most of the copper was still there.  Even the stuff I buried for an earlier radial system decades ago still has the copper jacket almost intact when I happen to dig up a piece that's still in the ground.

I probably didn't terminate the stranded copper correctly, and soldering it was most likely a mistake.  Split copper bolts work well for connecting  two  copper wires together.  Never use galvanised clamps for the purpose, because copper and zinc are highly reactive to one another and will corrode the first time it rains. Better still, use one continuous strand of wire for the OWL and dipole leg.
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« Reply #21 on: July 20, 2011, 12:28:07 PM »

I agree with Don about Copperweld which is a trade name, the junk is simply copper flashed as with welding wire or single pass plated at about .010".

Rural telephone wire is still available in #10 and 12 with .030" plating and a black nearly impervious jacket. If its going to be swinging in the wind terminate with a couple of guywire clamps and bent around a thimble. Use regular stranded wire as jumpers to the coax connector or solder lugs.

Flexweave is considered unreliable junk by the many DXers and contesters who jumped on it early.

Its pretty hard to beat 7 strand hard drawn copper in most enviroments, I have some here thats been recycled for about 45 years from 5 QTH's.

Carl



  I posted earlier but dropped out a comment about my Elmer's antenna. He swore by the old spring-temper drawn telephone service cable. I knew him for nearly 50 years and never once saw any of his wire down.

 And, yes the BRONZE wire I referred to was indeed phosphor bearing bronze wire. We still have it here at work on some large spools.
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« Reply #22 on: July 20, 2011, 12:59:32 PM »

The only time I ever saw #8 or #10 solid break from flexing was when a tree fell across it. My #10 open wire feedline has been up since '83. My reference 80 meter dipole has been up since '84.
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« Reply #23 on: July 20, 2011, 01:12:10 PM »

So many great points made here...
In Venice Ca, we rarely have significant weather events that demand the kind of treatment that you East Coasters do. My first Butternut lasted 8 years with one set of guys (black Dacron) and worked great for what it was, but the salt air eventually devoured it.
I agree with Don's take on the split bolt or "Kerney" method of splicing or termination. Anytime you mix metals, electrolysis can be a real bitch, especially in salt water environments. I prefer that over solder under tension any day. To me, the reason why soldered terminations always break is because the copper becomes annealed with heat, and therefore loses it's structural strength.
 
I think I'll be fine using stranded wire  due to the WX associated with my QTH. The spreaders I plan to use are schedule 80 UV resistant sections of 3/8's PVC. As to pre stretching the wire, what method(s) do you guys propose? Does rigging up a temporary stretch in place jig, and leave it in place for a while sound right?
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« Reply #24 on: July 20, 2011, 01:23:36 PM »

Quote
As to pre stretching the wire, what method(s) do you guys propose?

I actually hooked my wire that is still up for over 8 years to the back of my pick up truck ball hitch and a nearby tree and stretched it until it broke, and then spliced it back together. It was #10 stranded insulated wire.


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