It is common knowledge that a dipole antenna, at sufficient height, is an efficient antenna.
I’ve been exploring a dipole as an option for a permanent antenna. My explorations are currently constrained by two factors. First, I have no outside supports, poles, trees, etc. for hanging a dipole, nor will they fit within the HOA restrictions. Second, I have not yet decided to place anything in the attic space. Many advise that the space is difficult to navigate, mostly because of air-conditioning / heating ducts.
My first proof of concept idea was to hang a dipole inside the lanai (screened in back patio). A half-wave dipole fits in that space by wrapping about 1.5 feet around at each end. I made a simple dipole of speaker wire and positioned it at the top of the lanai, about 10 feet above ground. As with all my antenna experiments, I cut it to optimal length for resonance at 14.060 Mhz.
Results? It surprised me, since it was so low, by facilitating 89 QSOs that covered the eastern 2/3 of the continent, and one QSO with Spain.
OK. That worked. Yet, it is inside a structure. How much does that constrict it? The building is constructed of concrete block, covered with stucco. I don’t know if there is rebar in the supports or crossbars of the lanai. The lanai screen is a plastic mesh on an aluminum grid, and I imagine that has some effect. So, I moved it to the roof, getting it outside the cage and maybe 1 to 1.5 feet higher. Click the image and note the blue circle. The wires are at the same height and wrap just a bit around the corner edges. Stealthy, yes.
Results? So far, with fewer than 1/4th the number of QSOs, I have not met the reach of the inside version. Additionally, being exposed to occasional rain, it is fussier about staying tuned. SWR varies quite a bit from day to day. I’m not ready to take it down yet, but it is not a rousing success.
My first paragraph mentioned “at sufficient height.” We’re not there yet. I can gain more height by putting it inside the attic as an inverted vee. …sometime in the future…
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