Galvanised wire is very strong, that is for sure. It also conducts your applied current pretty well. Not as well as a pure copper wire, though.
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| Strong, but not ideal... |
Does this make any difference to the performance of your antenna? Overall, whilst calculations and theory, discussed with some degree of civility here, show that there will be somewhat less gain for an antenna made of steel, the operating experience will typically be that steel performs almost as well as copper.
The exact composition of steel wire, and how it is galvanised or coated dictates how precisely it compares to copper. Some are almost as good as copper, others will have significant gain losses.
The way to approach steel wire is this: why do you want to use it? Copper is the standard, proven material that ought to be used wherever possible. This means that only in violently windy and/or cold situations, or where access to an antenna after initial erection is extremely difficult should you consider using anything other than copper wire.
Keep in mind, too, that galvansed steel wire does corrode. That's because the ends, which are cut at some stage, expose the core to oxygen and moisture. This propagates along the rest of the wire at a modest but surprising rate, where the plastic coating serves only to maintain a moist atmosphere, hastening corrosion.
Stainless wire is also sometimes discussed, but it is also something to avoid in general, even though Optibeam are claimed to use it in their multi-band nested Moxon beam, which is a pretty expensive antenna.
FlexWeave is very strong, but rather heavy for some antenna designs. Kevlar-reinforced wire is also extremely strong in tension, and three times lighter than FlexWeave, but will fail from metal fatigue in bending eventually (about 2- 3 years in frequent winds.)
My advice is to use standard Kevlar-cored wire for all applications, and accept the need to replace it every few years.
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