Re: From NEC2 to the real world with accuracy

If I might anticipate because the copper oxidizes and presents a high
resistance to current, I would point out that enamel is even more
resistive and the current isn't going to travel through it either (the
current will travel through the proverbial path of least resistance -
under the coating of resistive layer covering no matter what it is
composed of).

(I am addressing more than one post with this response)

Basically I want to use copperweld for durability. Its not a matter of
saving money over hard drawn copper. I have no experience with (bare)
copperweld, but I have read that if you get a nick in the copper
layer, basically the steel will start rusting away at that point (very
quickly). So I don't have problem using some enamel to protect it (and
have done this in the past with hard drawn). I am using copperweld/
insulated wire for my low band antennas - but anyone who has actually
built a quad knows insulated wire is much too heavy, esp. when you are
dealing with 5 bands.

I have used hard drawn copper with enamel on it on 10 meters and never
had a problem with a wire breaking in 10 years. So, I am not really
sure if I need copperweld, but I have no expierence with larger quad
loops. The goal is to have this thing be reliable.

Regardless still - whatever I wire I use - even if it was bare #12
solid copper wire, I still want to go through the exercise of getting
the wire I actually used in sync with my model. So, I'd rather focus
the conversation on that topic.

With respect to manually tuning the quad (reflector) after its up,
yes, that seems to be the conventional wisdom. How practical and
possible is that for me? Mine will sit on 72' US Tower crankup/tilt
over - short of renting some huge bucket/boom, I can't see myself
manually tuning it when its up. The best I will do is take some type
of field measurements and see if it displays anything close to the
pattern NEC2 predicts - or better yet, just see if I am happy with it
as is. I did not have to make any adjustments to the monoband yagi
that went right from NEC2 to the tower, so, I am hoping for the same
good fortune.


-Scott, WU2X




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Relevant Pages

  • Re: From NEC2 to the real world with accuracy
    ... current will travel through the proverbial path of least resistance - ... saving money over hard drawn copper. ... So I don't have problem using some enamel to protect it (and ... built a quad knows insulated wire is much too heavy, ...
    (rec.radio.amateur.antenna)
  • Re: Why is copper better than steel for wire antenna?
    ... But the real problem is that steel is ferromagnetic -- in other words, ... This concentration of the current has the same result as passing the current through a wire of much smaller cross-sectional area: it greatly increases the resistance of the path carrying the current. ... Since the relationship between the depth of current flow and permeability is a square root, this means RF resistance of 10 to 100 or so times that of copper, as well as the higher resistance due to the higher DC material resistivity. ...
    (rec.radio.amateur.antenna)
  • Re: Best wire for long wire antenna
    ... strength comes largely from the copper core. ... I think you mean the strength comes from the steel core? ... IIRC it is rated on its 60Hz resistance as a competitor to HDC ... Unfortunately, this wire is only ...
    (rec.radio.amateur.antenna)
  • Re: Expressing fractions
    ... >> This is particularly puzzling since it should have a resistance that ... >> is less than the steel or the copper (and copper has considerably ... A voltage being established by joining ... But the voltage at the end of the wire could be nearly as high as the ...
    (sci.lang)
  • Re: ADSL - Getting BT To Install a New Copper Wire
    ... I've recently discovered that all the houses in our street ... originally had all copper wires running from the telephone poles ... back a copper wire as was originally there from the pole to the ...
    (uk.telecom.broadband)
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