{"id":416,"date":"2013-11-10T10:43:03","date_gmt":"2013-11-10T09:43:03","guid":{"rendered":"http:\/\/pa3hcm.utreg.net\/?p=416"},"modified":"2021-01-18T20:12:10","modified_gmt":"2021-01-18T19:12:10","slug":"j-pole-antennas-for-hf-bands","status":"publish","type":"post","link":"https:\/\/www.pa3hcm.nl\/?p=416","title":{"rendered":"J-pole antennas for HF bands"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Introduction<\/h2>\n\n\n\n<p>I&#8217;ve been using J-pole antennas on the 2m band from the first day I got licensed. They perform very well, are easy to construct and are cheap. Since Adrian PA0RDA and I have been experimenting with vertical antennas for HF, we came to the idea to try those J-poles on HF.<\/p>\n\n\n\n<p>This idea is not new. Many radio amateurs have tried this before, like <a href=\"http:\/\/www.qsl.net\/d\/dk7zb\/J_Pole\/wiremanjpole.htm\" target=\"_blank\" rel=\"noopener\">DK7ZB<\/a>. The J-pole antenna is almost identical to the Zepp-antenna, which is a still a popular HF-antenna.<\/p>\n\n\n\n<!--more-->\n\n\n\n<h2 class=\"wp-block-heading\">Construction<\/h2>\n\n\n\n<p>We made each J-pole of a single piece of wire. The length (l) is equal to the wavelength (wl), minus compensation due to velocity of propagation (v). At 3\/4 length the wire is bended 180 degrees and goes back up again, at a distance (d) from the other side. The length of the wire is:<\/p>\n\n\n\n<p>l = (wl * v) + d<\/p>\n\n\n\n<p>Here are some measurements we have used:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>HF band<\/td><td>wl<\/td><td>l (v=0.95)<\/td><\/tr><tr><td>17m<\/td><td>16.56m<\/td><td>15.81m<\/td><td>&nbsp;<\/td><\/tr><tr><td>30m<\/td><td>29.63m<\/td><td>28.23m<\/td><td>&nbsp;<\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Introduction I&#8217;ve been using J-pole antennas on the 2m band from the first day I got licensed. They perform very well, are easy to construct and are cheap. Since Adrian PA0RDA and I have been experimenting with vertical antennas for HF, we came to the idea to try those J-poles on HF. This idea is [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[54,55,34,37],"class_list":["post-416","post","type-post","status-publish","format-standard","hentry","category-antennas","tag-17m","tag-30m","tag-antenna","tag-vertical"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":6}},"_links":{"self":[{"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=\/wp\/v2\/posts\/416","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=416"}],"version-history":[{"count":3,"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=\/wp\/v2\/posts\/416\/revisions"}],"predecessor-version":[{"id":1939,"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=\/wp\/v2\/posts\/416\/revisions\/1939"}],"wp:attachment":[{"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=416"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=416"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pa3hcm.nl\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}