On Fri, 06 Oct 2006 05:21:00 GMT, Tony VE6MVP
wrote:

Folks

So I'm reading the 2006 ARRL Handbook page 22.6, There is a single
line stating "Steel wire is a poor conductor at RF; Avoid it." Any
idea why? Or is this just one of those physical properties?

So how much poorer than copper? Steel clothesline is easily obtained
and not that expensive. Admittedly though I haven't done much
research on copper or the other type of wires the Handbook mentions.


I am guessing that the "steel clothesline" to which you refer is
probably actually stranded (7x1?) heavy galvanised soft steel wire.

The galvanising is zinc or zinc/aluminium alloy and its thickness has
bearing on the answer for a specific frequency.

The stranding also has adverse effect on the effective RF resistance,
though not as predictable as the zinc coating.

Though it works, there are a number of mechanisms that increase the
loss, and the extent of some of them are quite difficult to predict or
to measure (for the average amateur).

The additional loss of steel wire is less important in an antenna
design that is loaded with bulk resistance, eg T2FD. A reason why
small guage stainless steel wire commonly used commercially on these
antennas isn't necessarily unsound. But that application should not
imply that small guage stainless steel is just as suited to a half
wave folded dipole.

Antenna wire would be one of the lowest cost elements of a complete
system, which questions the cost effectiveness of savings.

Owen
--

On Fri, 06 Oct 2006 22:17:10 GMT, Owen Duffy wrote:

Antenna wire would be one of the lowest cost elements of a complete
system, which questions the cost effectiveness of savings.

Sure, but clothesline wire is easily available in this small town.
Copper wire means I'd have to search it out in the nearest big city.

Tony

Tony VE6MVP wrote:
On Fri, 06 Oct 2006 22:17:10 GMT, Owen Duffy wrote:

Antenna wire would be one of the lowest cost elements of a complete
system, which questions the cost effectiveness of savings.

Sure, but clothesline wire is easily available in this small town.
Copper wire means I'd have to search it out in the nearest big city.

Tony

All the wire antennas I've built for the last 20 years or so have
been made out of electrical wire from the local home improvement
store.

They alway seem to outlive my interest in them.

--
Jim Pennino

Remove .spam.sux to reply.

On Sat, 07 Oct 2006 03:25:03 GMT, wrote:

Antenna wire would be one of the lowest cost elements of a complete
system, which questions the cost effectiveness of savings.

Sure, but clothesline wire is easily available in this small town.
Copper wire means I'd have to search it out in the nearest big city.

Tony

All the wire antennas I've built for the last 20 years or so have
been made out of electrical wire from the local home improvement
store.

They alway seem to outlive my interest in them.

Just standard household electrical wiring? So purchase some two wire
(actually three wire if you include the ground wire) electrical cable
and use the black and white wires? Will the insulation withstand the
out doors? Or do you strip off the insulation and use them bare?

Tony

Tony VE6MVP wrote:
On Sat, 07 Oct 2006 03:25:03 GMT, wrote:

Antenna wire would be one of the lowest cost elements of a complete
system, which questions the cost effectiveness of savings.

Sure, but clothesline wire is easily available in this small town.
Copper wire means I'd have to search it out in the nearest big city.

Tony

All the wire antennas I've built for the last 20 years or so have
been made out of electrical wire from the local home improvement
store.

They alway seem to outlive my interest in them.

Just standard household electrical wiring? So purchase some two wire
(actually three wire if you include the ground wire) electrical cable
and use the black and white wires? Will the insulation withstand the
out doors? Or do you strip off the insulation and use them bare?

Tony

Standard, single strand, solid, electrical wire, normally with the
insulation left on.

I usually buy blue so it blends with the sky.

Leaving the insulation on shortens the wire required ever so slightly.

The insulation lasts for years on everything I've ever put up.

--
Jim Pennino

Remove .spam.sux to reply.

Tony VE6MVP wrote:
On Sat, 07 Oct 2006 03:25:03 GMT, wrote:

Antenna wire would be one of the lowest cost elements of a complete
system, which questions the cost effectiveness of savings.

Sure, but clothesline wire is easily available in this small town.
Copper wire means I'd have to search it out in the nearest big city.

Tony

All the wire antennas I've built for the last 20 years or so have
been made out of electrical wire from the local home improvement
store.

They alway seem to outlive my interest in them.

Just standard household electrical wiring? So purchase some two wire
(actually three wire if you include the ground wire) electrical cable
and use the black and white wires? Will the insulation withstand the
out doors?

Not any of the multi-conductor household electrical wire ("Romex"),
find a spool of insulated #14 single-conductor "household wire" at any
decent neighborhood hardware store. Here in the southern provinces it's
called "#14 THHN" which comes in both solid and stranded types and in a
multitude of colors. I prefer stranded wire because it's less prone to
bending fatigue failure than is solid wire. Theoretically

If push comes to shove dial up a local electrician and ask where he
gets the stuff.

Personally I wouldn't string the wire thru bare screw eyes, I'd use the
Radio Shack catalog number 15-853 screwin insulated "TV cable
standoffs" to support it.

Or do you strip off the insulation and use them bare?

Leave the insulation alone, might get ugly after awhile but it lasts
forever out in the elements and has no discernable effect on the
performance of the wire as an HF loop antenna material.


Tony

Brian w3rv

The local price at Home Improvement stores is less than $25 for 500
feet of 14 gauge wire. I use electric fence insulators from the farm
supply store.

I have been disapointed in the mechanical strength of the Aluminum
electric fence wire.


On 6 Oct 2006 23:05:03 -0700, "Brian Kelly" wrote:

John Ferrell W8CCW
John Ferrell W8CCW

On Sat, 07 Oct 2006 14:20:38 -0400, John Ferrell
wrote:

The local price at Home Improvement stores is less than $25 for 500
feet of 14 gauge wire. I use electric fence insulators from the farm
supply store.

Oh, ok. Electric fence wire. I hadn't thought of that.

Tony

On Sat, 07 Oct 2006 14:20:38 -0400, John Ferrell
wrote:

I have been disapointed in the mechanical strength of the Aluminum
electric fence wire.

Aluminium is not very good material for fence wire and not usually a
substitute for steel in general fencing as it lacks the strength of
steel.

There are fence wires made from a steel core (typically high tensile)
and an aluminium (or aluminium / ~5% zinc) coating, sometimes with a
polymer coating over the top. These products are appearing as the new
"longlife galvanised" fence wires. Commonly the aluminium thickness is
around 30 microns, way less than skin depth at low HF, so they can be
expected to perform about as well as the high tensile steel core.

There are other products with a 200 micron cladding of 60%
conductivity aluminium over a high tensile core, and they look a good
prospect for antenna wire, 80% RF conductivity and 10000% strength
compared to the same diameter HDC. For example Gallagher XL 2.7mm
diameter wire (200 micron aluminium cladding) should have the same
loss as 2.3mm dia HDC, but over 10 times the Gross Breaking Strength.

To determine their likely loss as antenna wires, you need to know the
coating thickness.

Owen
--

On 6 Oct 2006 23:05:03 -0700, "Brian Kelly" wrote:

Not any of the multi-conductor household electrical wire ("Romex"),
find a spool of insulated #14 single-conductor "household wire" at any
decent neighborhood hardware store.

My cursory glance as I walked by the small town stores didn't see any
such but a few other stores, such as farm supply store, should have
such.

Personally I wouldn't string the wire thru bare screw eyes, I'd use the
Radio Shack catalog number 15-853 screwin insulated "TV cable
standoffs" to support it.

We don't have a Radio Shack store within a hundred miles. But I get
the idea. I'll go looking for some such.

Tony