New answers tagged wire-antenna
1
The important things to consider when choosing wire for a wire antenna are mechanical strength, electrical resistance, power-handling capability, cost, and ease of handling.
As an unsupported horizontally-strung wire gets longer its tension increases, which makes mechanical strength more important. A dipole for 160m is quite a long wire antenna. One should ...
0
The ladder line looks like a cable, as several people pointed out already.
As for the Yagi, it does look like a TV antenna, but there's a simple way to tell if it's currently used for ham radio or not: Does it move?
A TV antenna is stationary. It points towards in a particular direction towards a particular transmitter.
A ham radio VHF antenna is typically ...
2
The pictures look a lot like post-socialist country big city residental area. It may as well not be, YMMV.
The Yagi looks like an abandoned old analog TV antenna. Most ham installations use vertical polarization in UHF and this one looks pretty much horizontal.
The cable between the buildings is not an antenna at any rate. This is a communincations cabe of ...
5
The cable strung between the two buildings has two parts, a strong wire probably made of stainless steel or similar, then you can see some form of cable, as Tommexus said it's probably fibre or telephone cable, or maybe coax, hanging from the wire with lots of evenly spaced cable supports.
The steel wire is used to provide a strong support between the ...
13
It looks like a fibre or telephone cable strung between buildings.
It sets a good precedent for setting up your antenna though - if you can get access to the other rooftop at night, and a catapault or fishing rod. Make it fairly official-looking, with some large bolts and a labels with bar codes and lots of numbers.
0
I see knots being used for desktop lamps, after the wire enters the lamp, with stranded-wire. #1.) The more sharp the bend, the more you stress the wire and prepare it for breakage. As long as it's just one time, and no repeats, no bending and unbending, you should be fine. #2.) If you want to be safer, slip a little heat-shrink on first, tie the knot in the ...
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I would refrain from knotting antenna wire meant for a long-term installation. Knots in rope weaken the rope by 20% to 60% (source). I don't know of any research on knots in antenna wire, whether kevlar-reinforced or "knot" (sorry, couldn't resist the pun), but it seems reasonable to expect that tying a knot in antenna wire weakens it. You might ...
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Generally, stranded wire used for antennas is fine to knot. However, thin solid wire that is knotted or kinked can develop a weak spot that can break under tension.
You would not, for example, want to knot load bearing cable used as guy wire, even at the tips. Instead, you can use a wire thimble (selected as appropriate for wire diameter and alloy).
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It should be fine. Stranded wire will take that kind of bending easily. If you were to tie and untie the knot many times you might eventually weaken and break some of the strands, but if it's tied once and left in position, it won't create so much stress.
If you're worried, of course, there are alternatives — you could slide a small plastic bead onto the ...
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