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Author Topic: Antenna wire type  (Read 314 times)
N3ZJ
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Posts: 18




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« on: Yesterday at 10:13:01 AM »


I am contemplating a wire dipole for 80 meters and one for 160 meters. I have looked at various wire - but is there an advantage from one to the next. How is the "woven" wire compared with solid copper? Is the gauge a big factor? I am running about 600 watts output. Thanks!

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W5CPT
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Posts: 566




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« Reply #1 on: Yesterday at 02:20:32 PM »

I have used the woven wire and prefer it - BUT - it is not perfect. It kinks, and will break where it was kinked even if you do your very best to straighten it out.  Coated Flex Weave as is sold by Texas Towers and HRO is better than the bare wire. But it is pricey.  Solid wire is a poor choice as it stretches, especially in antennas as long as 80M & 160M.  Hard drawn (pre-stretched) wire is my end choice as it is half the price of Flex Weave and holds up well.

All that being said, the stranded wire you buy at Lowe's will work but will stretch over time, just not as much as solid conductor.  Be careful as retail wire can cost you more than purpose built wire (Flex Weave) even given the shipping if you don't have a Ham Radio store close enough to stop in.
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WB6BYU
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Posts: 13727




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« Reply #2 on: Yesterday at 03:16:45 PM »

It's more of a mechanical issue than an electrical one.  600W is less than 4A RMS into a 50 ohm load, and it
doesn't require a very big wire to handle that - #22 probably would work.

Soft-drawn copper wire (solid or stranded) only stretches when it is under sufficient tension.  Stretch might be an
issue if you are using it to guy your mast at the same time, but there is no need for that much tension on a dipole
otherwise.  (You'll never get it perfectly straight anyway.)  Even on 160m I rarely pull up more tension on the wire
than I can easily pull with one hand - probably 10 to 20 pounds at most.

Stranded wire is more flexible than solid, and that can be better when the antenna is blowing in the wind.
However, if you get solder in between the strands of the wire it becomes more brittle than solid
copper.  (So I tie the wire to an insulator to take the strain, with a pigtail that isn't under tension to make my
connections.)

CopperWeld is quite strong - that's what I'd use, for example, if I had to cross a street or parking lot where
there would be other people underneath.  It is a pain to work with, however, like a big spring.  Note that
real CopperWeld is something like 30% copper, so it has a good thick layer of copper.

Stranded CopperWeld is not as good of a choice, especially for 80m and 160.  That's because the
copper coating is applied to each individual strand, so the layer is thinner than for a single conductor.  As
you go lower in frequency the skin depth gets deeper, and once significant amounts of RF start flowing through
the underlying steel the losses increase.

Don't confuse real CopperWeld with copper-plated welding wire - the copper coating on the latter is made as
thin as possible, exacerbating hysteresis losses, and it can corrode off quite quickly.  A friend put up an antenna
using such wire and it worked for one night before it became an aerial dummy load.


For a permanent antenna, a spool of #12 or #14 insulated house wire, either stranded or solid, will about as well
as anything else unless there is a safety issue, in which case use CopperWeld.  For a portable or temporary that
you are going to be putting up and taking down frequently, something like Flex-Weave makes sense, though I get
by with #18 to #24 stranded, insulated hookup wire, as it is easy to work with.  (The PVC insulation decays in
the sun, and I have to replace the smaller sizes every 2 years or so here in Oregon because the insulation
contributes a significant part of the strength of the wire.  But that isn't a problem for antennas that I set up
a few weekends a year.)

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