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eHam Forums => Antennas, Towers and more => Topic started by: KB8VIV on October 13, 2018, 08:37:10 PM



Title: Antenna wire advice?
Post by: KB8VIV on October 13, 2018, 08:37:10 PM
Hello everyone,

So, a tree trimming company got tangled up in my full wave 80 meter loop - so it’s time to replace it. Trouble is, Davis Rf is out of the polystealth 13 awg that I used. Wireman is out of the comparable 531 - which I suspect is the same wire.

Does anyone have any recommendations for a good replacement? Thanks in advance.

De Kb8viv


Title: RE: Antenna wire advice?
Post by: NE1U on October 14, 2018, 05:39:28 AM
How much power are running?  If not legal limit, maybe drop a guage?

And, some are using wire from HD or Lowes swearing that all is good. Do a search for "THHN"


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 14, 2018, 04:23:37 PM
Hello,

I’m just running 100 watts.  I found this
https://www.homedepot.com/p/Southwire-500-ft-12-Black-Stranded-CU-THHN-Wire-22964158/203401696

This looks very similar
https://www.dxengineering.com/parts/dxe-antw-300


The Davis RF stuff is marketed as copper clad steel, supposedly the steel resists stretching.  It’s also marketed as uv resistant.  The Home Depot stuff looks like a good alternative though.  I may give Davis RF a week or two and then if they still don’t have it, I’ll get the Home Depot stuff.

Thanks for the recommendation.

73’s de kb8viv


Title: RE: Antenna wire advice?
Post by: KC0W on October 14, 2018, 04:41:19 PM
 Cooper clad is a real bitch to work with but it will stay up for a very, very long time. Antenna purists will say cooper clad is not as good as cooper wire due to it mostly being made out of steel. (with a minuscule outer layer of cooper) Cooper clad will not stretch like soft cooper wire will. Try not to disturb it's outer cooper jacket due to the possibility of rust forming............I would wait until it comes back in stock and order the cooper clad. Do it once & do it right.


                                                                Tom KC0W           


Title: RE: Antenna wire advice?
Post by: K0CWO on October 14, 2018, 05:10:24 PM
Wireman 531 is my first choice and I’ve used it quite a bit.  I’ve also used 12 AWG THHN for dipoles running legal limit without issues.  They work the same but 531 is more durable. 


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 14, 2018, 05:39:05 PM
Hello KC0W,

My Davis RF Polystealth wire has been up 15 years easily - it is a pain to work with as it really wants to be straight, LOL.  But it’s very rugged and has stood the test of time.  That said, it was no match for a stump grinder, LOL.

KB8VIV

Cooper clad is a real bitch to work with but it will stay up for a very, very long time. Antenna purists will say cooper clad is not as good as cooper wire due to it mostly being made out of steel. (with a minuscule outer layer of cooper) Cooper clad will not stretch like soft cooper wire will. Try not to disturb it's outer cooper jacket due to the possibility of rust forming............I would wait until it comes back in stock and order the cooper clad. Do it once & do it right.


                                                                Tom KC0W          



I suspect that the 531 is the same as the Davis RF as they are both mysteriously out of stock, and the eta is 2-3 weeks for both.  I will probably wait for one of them to come back in stock as, like KC0W stated previously, I only want to do it once.  All that said, if it doesn’t come back in stock soon, the DX Engineering looks like a good alternative.  I think I do prefer the copper clad steel of the 531/Davis rf as I imagine it would resist stretching better than the pure copper DX Engineering wire.  Thanks for all the advice.

73’s de kbIviv



Wireman 531 is my first choice and I’ve used it quite a bit.  I’ve also used 12 AWG THHN for dipoles running legal limit without issues.  They work the same but 531 is more durable.  


Title: RE: Antenna wire advice?
Post by: K4RVN on October 14, 2018, 05:46:47 PM
I presently have two antennas for 40 meters using the Southwire, except 14 gage. 1500 watts no problem, stranded black insulated copper. I got it at  either home Depot or Lowes for about 43 bucks for 500 ft. I use springs on the support ropes to lessen the stretch on the wire when the wind blows. Ropes are 3/16 dia. dacron, 4 element wire beam. Elements are full length for 40 meters around 7.168 freq. I think # 12 or #14 gage of the wire you posted would serve you well from my experience.


Title: RE: Antenna wire advice?
Post by: WB6BYU on October 14, 2018, 05:46:51 PM
Quote from: KC0W

...Antenna purists will say cooper clad is not as good as cooper wire due to it mostly being made out of steel. (with a minuscule outer layer of cooper)...


Genuine CopperWeld copper-clad steel wire is typically 20% to 30% copper (by weight).  For a solid wire
of reasonably large gauge the copper is thick enough that, due to skin effect, most of the RF flows in the copper
layer, at least on the higher bands.

But with stranded wire, each strand has a thinner copper layer, and the effective copper thickness of a larger
stranded wire is that of the individual strands on the outside of the bundle.  The lower the frequency, the skin
effect goes deeper, and losses increase once it gets into the steel underneath.  The more strands, the thinner
the layer of copper.

By contrast, copper-plated welding wire is often suggested for ham antennas.  This has a very thin
layer of copper - a few microns thick (the thinner the copper layer the better for it's intended use).  Not only
does most of the RF flow in the steel, but the copper layer corrodes off very quickly.  (One friend used it to put
up a rhombic for Field Day one year, and the copper disappeared overnight in a thick fog.)

So there is a big difference between copper-clad and copper-plated wire:  the former can be a good
choice for antennas in many cases, but not the latter.



Quote

...Cooper clad will not stretch like soft cooper wire will...



I've been putting up antennas for years, and the only time I've had a copper wire antenna stretch was when I
put my full weight on it because it was stuck in a tree.  For the last 30 years or so I've mostly been using thin
stranded, insulated hookup wire  from #18 to #26 or so.  As far as I'm concerned, if my wire stretches then
I'm putting too much tension on it.

I know all the antenna books show nice horizontal dipoles, but in practice a bit of sag doesn't hurt anything,
and helps the wire to withstand high winds that blow the supports around.  (Counterweights help, too.)


Title: RE: Antenna wire advice?
Post by: N5CM on October 14, 2018, 06:03:10 PM
I use #14 THHN stranded for my 350-foot loop.  Fed with heomebrew ladder line made from same wire.


Title: RE: Antenna wire advice?
Post by: KB2WIG on October 14, 2018, 06:19:53 PM


The local Homely despot                 #14 AWG THHN, 500 feet, $39.77.
Davis RF                                       #14 AWG CopperWeld , 500 feet, $75.00 + shipping.

You pay your money and you takes your choice.

I've used THHN and weed whacker line for years. If I had a nice place for, say, a 135 foot doublet fed with ladder line, at 120 feet above ground, I would use copper clad stuff. But I'm a poor man.....

klc


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 14, 2018, 06:37:31 PM
Thanks for all the great responses.  The Davis RF stuff isn’t cheap but I’ve had great experience with it, that said, I may give DX Engineering a call tomorrow and order some of this: https://www.dxengineering.com/parts/dxe-antw-300

Thanks again.

de Kb8viv



Title: RE: Antenna wire advice?
Post by: K4RVN on October 14, 2018, 06:53:50 PM
The Southwire coating on the insulation, like a varnish or something, will start to come off over time so it looks bad  but
still works fine. If looks are important to you I would go with the DX eng. wire as they say it is UV protected.
Frank


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 14, 2018, 07:16:18 PM
Hi Frank,

I’m less concerned with looks, I just don’t want the insulation to breakdown from the UV exposure.  The DX Engineering wire says it’s uv resistant which is definitely preferred.

73’s de Kb8viv.

The Southwire coating on the insulation, like a varnish or something, will start to come off over time so it looks bad  but
still works fine. If looks are important to you I would go with the DX eng. wire as they say it is UV protected.
Frank


Title: RE: Antenna wire advice?
Post by: WB6BYU on October 15, 2018, 06:21:35 AM
Quote from: K4RVN

The Southwire coating on the insulation, like a varnish or something, will start to come off over time so it looks bad  but
still works fine...



That's the nylon layer on the outside that reduces friction when pulling wires
through conduit.  When it starts looking bad, just lower your antenna (it is
installed with halyards, isn't it?) and stuff the debris off into a bucket, then
pull it back up.


Title: RE: Antenna wire advice?
Post by: K4RVN on October 15, 2018, 07:17:01 AM
The insulation on the Southwire remains intact after years of sun exposure so if not concerned about looks after time, the Southwire will do a good job at 14 gage or #12. I only use insulated wire because it is available and a reasonable price. If the insulation were to fall off no harm will be done except a slight resonant freq. change upward. I plan to install a half square for 75 meters soon with the #14 as I have had very good results over the years. It is not the best wire available but certainly cost effective that will last a long time. Good luck on your project,

Frank


Title: RE: Antenna wire advice?
Post by: WA7ARK on October 15, 2018, 07:23:22 AM
Has anybody put up a long run (I'm thinking 160meters) of insulated pure Cu #14 wire loosely twisted around steel fencing wire? The idea being that the steel wire act as a messenger cable to take the stress off the Cu wire?


Title: RE: Antenna wire advice?
Post by: N9AOP on October 15, 2018, 07:57:24 AM
What about SS wire?
Art


Title: RE: Antenna wire advice?
Post by: G3RZP on October 15, 2018, 08:05:36 AM
With the steel wire so closely coupled to the copper, there would be a current induced in it, and thus some loss. The loss would obviously be at the places where the current was highest and so probably wouldn't make a measurable difference.


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 15, 2018, 08:14:52 AM
Hi Art,

Never even considered it.  Do you have a link to some?  Thanks for the reply.

73’s de kb8viv

What about SS wire?
Art


Title: RE: Antenna wire advice?
Post by: WA7ARK on October 15, 2018, 08:25:42 AM
With the steel wire so closely coupled to the copper, there would be a current induced in it, and thus some loss. The loss would obviously be at the places where the current was highest and so probably wouldn't make a measurable difference.

Then how about using the low-stretch, high-tensile strength STI polyester cord  (http://www.dxstore.com/sti.html) as the messenger?



Title: RE: Antenna wire advice?
Post by: KB6HRT on October 15, 2018, 09:56:37 AM
Have played with wire antenna for years,  testing, comparing, an so on, Built brought and used most of the com manufactured antennas, of the com manufactured antennas the one's that have held up best were made with Nr 12 solid copper wire, an of the shorter ons NR 14 copper,, I like Nr 12 for 80m and NR14 for 40m-6m wire antennas, both don't stretch, have used copper coated Nr 14 making G5RV's and loops but found out after years of use my receive seemed to change some and incoming signal sounded not as clear from stations in the near field, so did some A/B testing an found that the new copper conductor antenna made to the same spec cleared up my problem. The  problem has never returned an its been 5 years now. My guess is after the copper burned out after a fue years, the antenna changed in resistance some.  Like when you touch up a antenna circuit using your radios tuner to bring  the SWR to flat..............73s......kb6hrt


Title: RE: Antenna wire advice?
Post by: G3RZP on October 15, 2018, 11:59:58 AM

Quote
Then how about using the low-stretch, high-tensile strength STI polyester cord  as the messenger?

You MIGHT see a change in feed impedance/resonant frequency if/when it gets water logged. Whether the change would be enough to worry about, I would doubt until proved otherwise....Anyhow, what are antenna tuners for? Too many people are under the apprehension that an antenna must be resonant to  radiate...


Title: RE: Antenna wire advice?
Post by: K0CWO on October 15, 2018, 05:11:05 PM
I’ve used stainless steel wire constructing an 80 meter doublet before.  I could not tell the difference between it and the copper clad steel doublet it replaced.


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 15, 2018, 05:31:03 PM
The more I look at my setup, in the woods, the more convinced I am to wait for the Davis RF to come back into stock.  Lots of branches and tree limbs to rub against and more than once I’ve had branches fall on my wire.  No damage to the wire, it’s rugged and I think I need that for my situation.

I also received an email from Davis RF; 3-4 weeks is the eta.

Thanks again everyone.

Kb8viv


Title: RE: Antenna wire advice?
Post by: WA7ARK on October 16, 2018, 11:27:59 AM

Quote
Then how about using the low-stretch, high-tensile strength STI polyester cord  as the messenger?

You MIGHT see a change in feed impedance/resonant frequency if/when it gets water logged....

We average about 320 sunny days a year in this part of Arizona... ;D


Title: RE: Antenna wire advice?
Post by: WA7PRC on October 16, 2018, 11:54:45 AM
And of course, any wire you buy at the box store is going to be soft-drawn copper.
OTOH, all antenna wire is either hard-drawn copper or copper-clad steel.
"THHN" specifies only the insulation... which (unless you're wiring a structure) is meaningless.


Title: RE: Antenna wire advice?
Post by: KM1H on October 16, 2018, 12:48:11 PM
Ive found that some second hand deep well wire is hard drawn, or certainly not soft. Around here lengths in the 100-1000' range of #12 to #6 are available for the asking or at scrap prices.
It comes in two and three pair versions (depending on the type of pump motor) and is twisted so it takes patience to get it useful.

Ive used #10 and 8 for decades for 160 and 80M sloping verticals off a 160/180' (it grew 2 sections) and 100' towers with no noticeable stretch or resonance changes. Plus the elevated radials are usually #12 for the first 4 to 8 and then whatever else of smaller gauges is available.

Carl


Title: RE: Antenna wire advice?
Post by: K4JUL on October 17, 2018, 01:10:51 PM

FYI - Found this ... 18 ga black insulated automotive wire (cars, trailer wiring etc) that I believe is UV resistance ... and near invisible against the sky for those with CC&R or HOA Cops running around whining about everything:

    https://www.wiringproducts.com/18-awg-black-automotive-wire-500-ft-spool.html


Brian
K4JUL




Title: RE: Antenna wire advice?
Post by: K4RVN on October 20, 2018, 04:27:05 PM
Brian, I would pass on the wire you posted as it costs more than the insulated #14 house wiring stranded cooper from Lowes or Home Depot. In addition the shipping is not free. # 18 copper is a little light duty in my opinion for some antennas. For 5 bucks more you can also buy #12 wire on a 500 ft roll which is stronger.

Frank


Title: RE: Antenna wire advice?
Post by: WA7PRC on October 20, 2018, 08:57:38 PM
Quote
Brian, I would pass on the wire you posted as it costs more than the insulated #14 house wiring stranded cooper from Lowes or Home Depot. In addition the shipping is not free. # 18 copper is a little light duty in my opinion for some antennas. For 5 bucks more you can also buy #12 wire on a 500 ft roll which is stronger.
ALL AC electrical service wire is soft-drawn, and will stretch, the same as automotive wire.

Stranded electrical service wire contains only 7 strands. When used in a wire antenna, it will fatigue and break sooner than wire with more strands. 19-strands is better; 34 strands is better yet. Antenna wire has to withstand continual bending in the wind, and is commonly available in up to 168 strands (14 ga) and 259 strands (12 ga).

The insulation used in electrical and automotive service wire isn't specified for outdoor use, and in UV light, will deteriorate sooner when used as an antenna. However, because it is sold by the trainload, the cost is least.  To some, that is the most (or only) important characteristic.

OTOH, the hard drawn 168- and 259-strand antenna wire I bought has given me almost ZERO issues over more than a dozen years. It just costs more... ONCE in a great while.


Title: RE: Antenna wire advice?
Post by: KM1H on October 21, 2018, 11:21:33 AM
Im still using some #14 hard drawn copper 7 strand antenna wire Ive had since the early 60's at many homes on a T2FD, and copper clad steel versions have been up at 180' for 160/80 inverted V's for almost 20 years.

Ive no experience but have heard the 168 strand stuff sold by small ham companies has poor long term survivability in some environments.

FWIW

Carl
Ham since 1955
Extra since 1968


Title: RE: Antenna wire advice?
Post by: WA7PRC on October 21, 2018, 12:00:00 PM
Ive no experience but have heard the 168 strand stuff sold by small ham companies has poor long term survivability in some environments.
The 12ga 259-strand stuff I bought from Steve Davis (Davis RF in NH, link (http://www.davisrf.com/antenna-wire/)) lasted almost 20 years before finally rotting thru. I guess it didn't like the salt air around here.


Title: RE: Antenna wire advice?
Post by: KM1H on October 21, 2018, 01:58:00 PM
Why would it rot thru?  I get salt air, acid rain, and other pollutants to deal with and nothing has lost any strength.

Davis is the one I was actually referring to above. Do they use some additive to the copper??

Carl


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 21, 2018, 03:00:14 PM
This place is awesome, now I’m thinking the polyethylene covered #12 flexweave might be a good option.  I like the pe cover as it’s highly abrasion resistant and my antenna rubs against branches etc.  I do like the copper clad steel’s strength properties as I’ve had branches come down on my old wire with no ill effects, I don’t know if the flexweave would survive this.

It sounds like the electrical properties would be better in the flexweave, being all copper.  What do you all think?

Thanks again,

De Kb8viv


Title: RE: Antenna wire advice?
Post by: KM1H on October 21, 2018, 04:19:45 PM
The RF flows VERY close to the copper surface only on HF, called skin depth, and the steel is only for strength. No jacket will survive tree branches rubbing for very long and the Flexweave uses many very small fragile strands that will go next.

Your choice.

Carl


Title: RE: Antenna wire advice?
Post by: N3HEE on October 23, 2018, 07:09:17 AM
I use #14-7STRCU-HDPE from The RF Connection.  It has a VERY thick HDPE jacket.  I pulled it down yesterday and even though it's been abused by the sun, wind and trees for two years it looked like new.  Good stuff !  https://rfconnection.com/antenna-wire/


Title: RE: Antenna wire advice?
Post by: KB8VIV on October 23, 2018, 07:58:16 AM
Hi Joe,

Excellent, thank you for the recomendation.

73’s de Kb8viv


Title: RE: Antenna wire advice?
Post by: KM1H on October 23, 2018, 12:33:04 PM
I use #14-7STRCU-HDPE from The RF Connection.  It has a VERY thick HDPE jacket.  I pulled it down yesterday and even though it's been abused by the sun, wind and trees for two years it looked like new.  Good stuff !  https://rfconnection.com/antenna-wire/

But 2 years in MD flatlands is not the same as elsewhere and plus at elevation.

Quote
Normally HDPE has a poor resistance to UV, a segment of sun light. Milk jugs are made from HDPE and designed for a short shelf life. After all, they are made to contain perishable food. The whitish, translucent appearance is the natural color of HDPE.

Additives can extend that life.

Carl


Title: RE: Antenna wire advice?
Post by: VK2LEE on October 26, 2018, 04:11:56 AM
Hi, I have always used 4mm or even 3mm stranded copper wire pvc coated for My wire antennas without any problems apart from Cockatoos chewing the wires at times or even worse chewing the coaxial cable..... I just buy Automotive pvc covered stranded copper wire 3mm or 4mm....  works a treat and can last for many years even with our ozone layer hole and terrible UV problems...  in Australia....  My inverted vee for 80 meters is mounted on one end in a tree which sways a lot with the winds We have been getting... and no problems at all...  RECOMMENDED... NOT EXPENSIVE...   LEE  VK2LEE


Title: RE: Antenna wire advice?
Post by: KB8VIV on November 29, 2018, 07:22:27 PM
Ahhh...the wait is over - Davis RF shipped my copper clad steel poly-s 13.  Now I have NE Ohio to contend with.

Thanks again everyone.

73’s de Kb8viv.