{"id":133,"date":"2024-01-07T02:01:49","date_gmt":"2024-01-07T02:01:49","guid":{"rendered":"https:\/\/www.bob-easton.com\/n4ree\/?p=133"},"modified":"2024-01-07T20:05:54","modified_gmt":"2024-01-07T20:05:54","slug":"rooftop-20m-dipole","status":"publish","type":"post","link":"https:\/\/www.bob-easton.com\/n4ree\/2024\/01\/07\/rooftop-20m-dipole\/","title":{"rendered":"Rooftop 20M Dipole"},"content":{"rendered":"\n

It is common knowledge that a dipole antenna, at sufficient height, is an efficient antenna.<\/p>\n\n\n\n

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.<\/p>\n\n\n\n

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. <\/p>\n\n\n\n

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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.<\/p>\n<\/div>

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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.<\/p>\n<\/div><\/div>\n\n\n\n

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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.<\/p>\n<\/div>

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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…<\/p>\n","protected":false},"excerpt":{"rendered":"

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 […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[3],"tags":[],"class_list":["post-133","post","type-post","status-publish","format-standard","category-antennas","entry"],"featured_image_src":null,"featured_image_src_square":null,"author_info":{"display_name":"Bob Easton","author_link":"https:\/\/www.bob-easton.com\/n4ree\/author\/n4ree\/"},"_links":{"self":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts\/133","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/comments?post=133"}],"version-history":[{"count":4,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts\/133\/revisions"}],"predecessor-version":[{"id":142,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts\/133\/revisions\/142"}],"wp:attachment":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/media?parent=133"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/categories?post=133"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/tags?post=133"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}