>
>Guys,
>
>Reviewing the wireman's "Loss Graph for Matched Transmission Lines" chart,
>and I noticed #12AWG Twin Open Wire, as having the lowest loss by a long
>way. I guess I have never seen Open Wire as shown on a chart before to
>reinforce just how low the loss really is.
>Being a novice antenna guru, I have a few questions:
>
>How far away from the ground does this stuff need to be?
// My guess is that it should be >5-times the wire-spacing.
>What are the drawbacks of using it?
>
It won't work as advertised when fed from an unbalanced tuner with a 1 to
1 balun at the output. However, a Balanced L-network antenna tuner is
not hard to construct. An article was published in the February, 1990
*QST*. The manuscript for the balanced tuner article is available on my
Web site.
>I have a remote dipole that this stuff might be just the ticket for a long
>run. I have always used coax, except for some plastic windowed ladder
>line, which always worked nicely, but according to the chart has more loss
>that the Twin Open Wire.
// Yea, verily. . . Homebrewed #12-solid-Cu open wire line has low
loss - even with over the top SWR, so the antenna it feeds works for
multiband use. However, open wire feedline needs to be guyed with 2
Dacron cords to keep it from flailing around in strong winds.
>
>My guess is that this is the 6" spaced feedline I have seen before. I
>would make this and wonder what people use for the spacers, what spacing is
>required, etc.
// The above article also describes a simple way of constructing
open-wire feedline using commonly available materials and tools.
good luck, Eric
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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