{"id":1034,"date":"2012-11-20T20:46:12","date_gmt":"2012-11-20T23:46:12","guid":{"rendered":"http:\/\/blog.sarmento.eng.br\/?p=1034"},"modified":"2014-12-23T20:05:11","modified_gmt":"2014-12-23T23:05:11","slug":"just-checking-magnetic-loop-antennas-rgp3-for-mw","status":"publish","type":"post","link":"https:\/\/radio.sarmento.eng.br\/?p=1034","title":{"rendered":"Just checking magnetic loop antennas &#8211; RGP3 for MW"},"content":{"rendered":"<p>Holiday, a rainy day, some enameled copper wire and here we go in another experiment with small loop antennas.<\/p>\n<p>The famous RGP3, developed by Rene Passold based in an old project called &#8220;bazooka antenna&#8221;, is spread over MW dxers in Brazil, and still represents opportunities for testing several configurations, specially related to the coil.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.sarmento.eng.br\/Fotos\/Antenas\/rgp3_longa_cobre_esmaltado.jpg\" alt=\"RGP3 magnetic loop antenna\" \/><\/p>\n<p>In this experience, I checked two forms of winding the coil, with turns together and spaced by a constant distance using a common string.<\/p>\n<p>And the results confirm that spacing the turns makes the tuning range wider, due to less capacitance losses. Both performance are similar, not noticed using a standard receiver like a Grundig YB400, that shows a small but reliable s-meter (not professional but adequate to fine tuning small loops).<\/p>\n<p>The format of ferrite rod were kept the same as the original RGP3, but this one I got glued two sets of ferrite to check with sensibility would be better. Practical experience shows no sensible improvement doubling the number of ferrite rods aligned in the axis.<\/p>\n<p>But its nulling capacity seams to be a little bit better.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.sarmento.eng.br\/Fotos\/Antenas\/Loop_Ferrite_40mm_a.jpg\" alt=\"RGP3 magnetic loop antenna\" \/><br \/>\n<em>Final product and the inductive coupling with the internal ferrite antenna of a portable MW receiver<\/em><\/p>\n<p>Instead of using Litz Wire that requires some time and tricks to get good soldering, I adopted enameled copper wire due its rigid construction and overall quality showed for the small loops.<\/p>\n<p>That\u00b4s all folks.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Holiday, a rainy day, some enameled copper wire and here we go in another experiment with small loop antennas. The famous RGP3, developed by Rene Passold based in an old project called &#8220;bazooka antenna&#8221;, is spread over MW dxers in &hellip; <a href=\"https:\/\/radio.sarmento.eng.br\/?p=1034\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-1034","post","type-post","status-publish","format-standard","hentry","category-telecomunicacoes"],"_links":{"self":[{"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=\/wp\/v2\/posts\/1034","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1034"}],"version-history":[{"count":17,"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=\/wp\/v2\/posts\/1034\/revisions"}],"predecessor-version":[{"id":1696,"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=\/wp\/v2\/posts\/1034\/revisions\/1696"}],"wp:attachment":[{"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1034"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1034"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/radio.sarmento.eng.br\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1034"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}