{"id":61,"date":"2023-10-29T09:48:26","date_gmt":"2023-10-29T09:48:26","guid":{"rendered":"https:\/\/www.oe3kun.at\/?page_id=61"},"modified":"2023-11-11T16:27:05","modified_gmt":"2023-11-11T16:27:05","slug":"20m-efhw-antenna","status":"publish","type":"page","link":"https:\/\/www.oe3kun.at\/?page_id=61","title":{"rendered":"20m EFHW Antenna"},"content":{"rendered":"\n<p>Due to the <a href=\"https:\/\/www.oe3kun.at\/?page_id=81\" data-type=\"page\" data-id=\"81\">restricted space<\/a> I have to place my antennas I was looking for a solution which needs to cover several points.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>It needs to be a vertical antenna since horizontal there are only a few meters available. <\/li>\n\n\n\n<li>It may not be fixed to avoid troubles with the HOA.<\/li>\n\n\n\n<li>I don&#8217;t want to work with short antennas compensated by coils.<\/li>\n\n\n\n<li>It should be kind of an end fed since I can not easily access the area above the ground (balcony)<\/li>\n<\/ul>\n\n\n\n<p>So I came to the conclusion that an expandable fiber pole would solve my issues. It&#8217;s vertical -> check; I can collapse it to about 1 meter height from the ground and mount it on the inner side of my balcony. HOA troubles avoided -> check; No coils needed. I can expand the antenna to about 13 meters what allows me to use even a 20 meter end fed half wave -> check.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The Materials and Tools<\/h2>\n\n\n\n<p>There is not much needed to set up the EFHW antenna. Just some cable with an UnUn to transform the impedance and the fiber pole. Some tools like wire cutter and stripper and a nanoVNA to measure the right length of the wire. <\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_tools-1024x768.jpg\" alt=\"\" class=\"wp-image-162\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_tools-1024x768.jpg 1024w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_tools-300x225.jpg 300w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_tools-768x576.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_tools-1536x1152.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_tools-2048x1536.jpg 2048w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_tools-400x300.jpg 400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">The Fiber Pole<\/h2>\n\n\n\n<p>To mount the antenna I used a about 13 meter long expandable\/collapsible fiberglass pole. This pole I mounted with some strips to the backside of my balcony.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun-1024x768.jpg\" alt=\"\" class=\"wp-image-161\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun-1024x768.jpg 1024w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun-300x225.jpg 300w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun-768x576.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun-1536x1152.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun-2048x1536.jpg 2048w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun-400x300.jpg 400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Since I don&#8217;t want to remove the pole every time I have to expand it I mounted a tiny fishing line to the top element. Otherwise I would have to tilt the pole that the top element slides out since it&#8217; does not stick out. The fishing line will be on the top of the pole elements and just need to pull to get the top element out.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"1024\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_pull-768x1024.jpg\" alt=\"\" class=\"wp-image-160\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_pull-768x1024.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_pull-225x300.jpg 225w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_pull-1152x1536.jpg 1152w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_pull-1536x2048.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_pull-scaled.jpg 1920w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">The 1:49 UnUn<\/h2>\n\n\n\n<p>Nothing special to say here. Because it&#8217;s an EndFedHalfWave a transformation of impedance from 50 to about 2500 ohm is needed. <\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"1024\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun_big-768x1024.jpg\" alt=\"\" class=\"wp-image-159\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun_big-768x1024.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun_big-225x300.jpg 225w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun_big-1152x1536.jpg 1152w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun_big-1536x2048.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_unun_big-scaled.jpg 1920w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">The Antenna Wire<\/h2>\n\n\n\n<p>As wire I used a lightweight DX wire since the fiber glass pole is quite sensitive to weight. The wire is tied to the silicon nozzle and the nozzle pulled over the top of the top element. So it&#8217;s easy to shift the wire toward heaven together with the pole elements. Even it sound a bit wiggly the mount is surprisingly stable.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_silicon_noozle-1024x768.jpg\" alt=\"\" class=\"wp-image-165\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_silicon_noozle-1024x768.jpg 1024w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_silicon_noozle-300x225.jpg 300w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_silicon_noozle-768x576.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_silicon_noozle-1536x1152.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_silicon_noozle-2048x1536.jpg 2048w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_silicon_noozle-400x300.jpg 400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Measure &#8211; Cut &#8211; Measure<\/h2>\n\n\n\n<p>It&#8217;s time to strip the wire to the proper length. So it&#8217;s an repeating exercise to connect the nanoVNA to the wire and measure the current SWR. Having a look at the current resonance frequency and to decide how much wire can be cut. I was quite off of my 20 meter target frequency of 14,2 MHz. But after several cuts I met the desired frequency. Honestly I have to admit that I had really luck. Since I cut off just bigger parts of the cable and hit the needed length very exact.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_cuttings-1024x768.jpg\" alt=\"\" class=\"wp-image-154\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_cuttings-1024x768.jpg 1024w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_cuttings-300x225.jpg 300w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_cuttings-768x576.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_cuttings-1536x1152.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_cuttings-2048x1536.jpg 2048w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_cuttings-400x300.jpg 400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_end_point-1024x768.jpg\" alt=\"\" class=\"wp-image-155\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_end_point-1024x768.jpg 1024w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_end_point-300x225.jpg 300w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_end_point-768x576.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_end_point-1536x1152.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_end_point-2048x1536.jpg 2048w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_end_point-400x300.jpg 400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Let&#8217;s zoom a bit in. A SWR of 1.05 at 14,34 MHz is promising. Due to the limited resolution of the nanoVNA with 100 point and my scan width from 1 &#8211; 30 MHz it will not tell me the SWR 14.2 MHz.<\/p>\n\n\n\n<p>After I zoomed in I am happy and satisfied. The antenna should work well on 20 meters.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_final_cut-1024x768.jpg\" alt=\"\" class=\"wp-image-156\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_final_cut-1024x768.jpg 1024w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_final_cut-300x225.jpg 300w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_final_cut-768x576.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_final_cut-1536x1152.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_final_cut-2048x1536.jpg 2048w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_vna_final_cut-400x300.jpg 400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p>It was easy and quick to set up this 20 meter EFHW antenna. Including the fixing of the pole it took me about 2 hours. The result is good and regarding the usage the setup from expanding the pole to starting QSOs is very fast. Collapsed it is almost not recognizable from the ground.<\/p>\n\n\n\n<p>Important is to take care about the weather situation. As I learned the pole will bend to a good extend if it is stormy. It will not be damaged but it looks a bit weird \ud83d\ude42<\/p>\n\n\n\n<p>Below a few impressions where the height of the pole can be better understood.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"1024\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_sky_view-768x1024.jpg\" alt=\"\" class=\"wp-image-158\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_sky_view-768x1024.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_sky_view-225x300.jpg 225w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_sky_view-1152x1536.jpg 1152w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_sky_view-1536x2048.jpg 1536w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_antenna_pole_sky_view-scaled.jpg 1920w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><\/figure>\n\n\n\n<p>Comparison to the height of the house<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"1024\" src=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_pole_size-768x1024.jpg\" alt=\"\" class=\"wp-image-166\" srcset=\"https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_pole_size-768x1024.jpg 768w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_pole_size-225x300.jpg 225w, https:\/\/www.oe3kun.at\/wp-content\/uploads\/2023\/11\/efhw_20m_pole_size.jpg 960w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Due to the restricted space I have to place my antennas I was looking for a solution which needs to cover several points. So I came to the conclusion that an expandable fiber pole would solve my issues. It&#8217;s vertical &hellip; <a href=\"https:\/\/www.oe3kun.at\/?page_id=61\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-61","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=\/wp\/v2\/pages\/61","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=61"}],"version-history":[{"count":3,"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=\/wp\/v2\/pages\/61\/revisions"}],"predecessor-version":[{"id":167,"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=\/wp\/v2\/pages\/61\/revisions\/167"}],"wp:attachment":[{"href":"https:\/\/www.oe3kun.at\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=61"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}