{"id":10637,"date":"2026-01-05T08:58:02","date_gmt":"2026-01-05T07:58:02","guid":{"rendered":"https:\/\/www.ik0vve.net\/?p=10637"},"modified":"2026-01-05T08:58:04","modified_gmt":"2026-01-05T07:58:04","slug":"pills-of-technique-the-balun-the-bridge-for-your-antenna","status":"publish","type":"post","link":"https:\/\/www.ik0vve.net\/?p=10637","title":{"rendered":"\u201cPills of Technique\u201d: The Balun \u2013 The Bridge for your Antenna"},"content":{"rendered":"\n<p><strong>Welcome to \u201cPills of Technique\u201d<\/strong>. In the <a rel=\"noreferrer noopener\" href=\"https:\/\/www.ik0vve.net\/?p=10491\" target=\"_blank\">previous post<\/a> we learned how to build a dipole. Now, it&#8217;s time to talk about the &#8220;bridge&#8221; that connects your radio to the antenna: the <strong>Balun<\/strong>.<\/p>\n\n\n\n<h3>1. What is a Balun?<\/h3>\n\n\n\n<p>The name is a contraction of <strong>BAL<\/strong>anced to <strong>UN<\/strong>balanced.<\/p>\n\n\n\n<ul>\n<li><strong>Balanced:<\/strong> Your dipole is a balanced antenna (two identical halves).<\/li>\n\n\n\n<li><strong>Unbalanced:<\/strong> Your coaxial cable is unbalanced (the center conductor is protected by the shield).<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image.png\"><img decoding=\"async\" loading=\"lazy\" width=\"1024\" height=\"565\" src=\"https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image.png\" alt=\"\" class=\"wp-image-10639\" srcset=\"https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image.png 1024w, https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image-300x166.png 300w, https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image-768x424.png 768w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">from <a href=\"http:\/\/PA9X.com\" data-type=\"URL\" data-id=\"PA9X.com\" target=\"_blank\" rel=\"noreferrer noopener\">PA9X.com<\/a> website<\/figcaption><\/figure>\n\n\n\n<h3>2. Why do you need it?<\/h3>\n\n\n\n<p>If you connect a coaxial cable directly to a dipole, the RF current starts flowing on the outside of the cable shield. This is called Common Mode Current.<\/p>\n\n\n\n<p>The consequences are:<\/p>\n\n\n\n<ul>\n<li><strong>RF in the Shack:<\/strong> Your radio, microphone, or even your mouse might behave strangely during transmission.<\/li>\n\n\n\n<li><strong>Noise:<\/strong> The cable starts acting like an antenna, picking up interference from LED lights, PCs, and appliances in your house.<\/li>\n\n\n\n<li><strong>Distorted Signal:<\/strong> The radiation pattern of your antenna changes, and it won&#8217;t perform as calculated.<\/li>\n<\/ul>\n\n\n\n<h3>3. The &#8220;Ugly Balun&#8221; (Air-Core Choke)<\/h3>\n\n\n\n<p>The simplest way to stop these unwanted currents is to create an <strong>Ugly Balun<\/strong>. It is called &#8220;ugly&#8221; because it\u2019s just a coil of coaxial cable, but it works great for a single band!<\/p>\n\n\n\n<p><strong>How to make it:<\/strong><\/p>\n\n\n\n<ol start=\"1\">\n<li>Take a PVC pipe (diameter about 10-15 cm).<\/li>\n\n\n\n<li>Wind about 4-6 meters of your coaxial cable (RG-58 or RG-213) around the pipe.<\/li>\n\n\n\n<li>Secure the turns with cable ties or tape.<\/li>\n\n\n\n<li>Place it right at the antenna feed point.<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-image size-full is-style-default\"><a href=\"https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image-1.png\"><img decoding=\"async\" loading=\"lazy\" width=\"1024\" height=\"816\" src=\"https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image-1.png\" alt=\"\" class=\"wp-image-10640\" srcset=\"https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image-1.png 1024w, https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image-1-300x239.png 300w, https:\/\/www.ik0vve.net\/wp-content\/uploads\/2026\/01\/image-1-768x612.png 768w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">from <a href=\"http:\/\/q82.uk\" data-type=\"URL\" data-id=\"q82.uk\" target=\"_blank\" rel=\"noreferrer noopener\">q82.uk<\/a><\/figcaption><\/figure>\n\n\n\n<h3>4. Deepening and Technical Resources<\/h3>\n\n\n\n<p>If you want to understand the physics behind this or see professional measurements, I highly recommend these resources:<\/p>\n\n\n\n<ul>\n<li><strong><a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/www.iz2uuf.net\/wp\/index.php\/2013\/05\/18\/balun1\/\">IZ2UUF &#8211; Balun 1:1: come farlo e perch\u00e9<\/a>:<\/strong> An excellent and deep technical analysis (in Italian) about why we need Baluns and how they work.<\/li>\n\n\n\n<li><strong><a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/www.google.com\/search?q=https:\/\/vk6ysf.com\/balun_choke_barrett.htm\">VK6YSF &#8211; 1:1 Choke Balun<\/a>:<\/strong> Practical examples of Baluns made with ferrite cores.<\/li>\n\n\n\n<li><strong><a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/en.wikipedia.org\/wiki\/Balun\">Wikipedia &#8211; Balun Concepts<\/a>:<\/strong> For a general overview of the different types (Voltage vs Current baluns).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<blockquote class=\"wp-block-quote\">\n<p><strong>Pro Tip:<\/strong> If you are using a multi-band antenna or an ATU (Antenna Tuner), a Balun is even more important to keep the SWR stable and avoid &#8220;hot&#8221; metal chassis in your station!<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>Enjoy your DIY experiments!<\/p>\n\n\n\n<p>If you have questions or want to suggest the next &#8220;Pill&#8221;, write me a comment!<\/p>\n\n\n\n<p><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3><\/h3>\n","protected":false},"excerpt":{"rendered":"<p>Welcome to \u201cPills of Technique\u201d. In the previous post we<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[13,178,179,168,7],"tags":[152,176,170,180,169],"_links":{"self":[{"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=\/wp\/v2\/posts\/10637"}],"collection":[{"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10637"}],"version-history":[{"count":6,"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=\/wp\/v2\/posts\/10637\/revisions"}],"predecessor-version":[{"id":10645,"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=\/wp\/v2\/posts\/10637\/revisions\/10645"}],"wp:attachment":[{"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10637"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10637"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ik0vve.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10637"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}