{"id":397,"date":"2018-12-17T01:56:44","date_gmt":"2018-12-17T01:56:44","guid":{"rendered":"https:\/\/www.nf8m.com\/nf8m\/?p=397"},"modified":"2018-12-18T21:23:41","modified_gmt":"2018-12-18T21:23:41","slug":"beverage-antenna-project","status":"publish","type":"post","link":"https:\/\/www.nf8m.com\/nf8m\/beverage-antenna-project\/","title":{"rendered":"Beverage antenna project"},"content":{"rendered":"<p>A few years ago I built a shielded loop for receiving on 160 meters, but after attending W3LPL&#8217;s Contest University session on effective top band antennas, I thought about installing a better receive antenna. The loop does a decent job, with the 15 dB preamp I built to go along with it, but Frank pointed out that a Beverage antenna generally has better gain, directivity, and front\/back ratio than a loop. There happens to be some forested land behind and down the block from our house, so I decided to try putting up a Beverage and see how it works.<!--more--><\/p>\n<p>Most Beverage antennas are directive in a single direction, but it&#8217;s possible to build a reversible Beverage if the proper transformer and termination configuration is used. Due to the complexity of building the networks and doing it right, I picked up a pair of KD9SV reversible Beverage antenna transformers from DX Engineering. I had a few hundred feet of surplus twisted pair telephone wire, and hung it in the trees from the corner of my yard and off into the woods. It&#8217;s about 250 feet long, or roughly a half wavelength on 160 and a full wavelength on 80 meters, which is about the minimum length for the antenna to be effective.<\/p>\n<p>The KD9SV transformers connect to the twisted pair at each end. The far end is grounded with either a short radial system or a four foot ground rod, and the near end is likewise grounded and has a pair of F connectors, one for the <a href=\"https:\/\/www.nf8m.com\/nf8m\/wp-content\/uploads\/2018\/12\/beverage_relays.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-medium wp-image-400\" src=\"https:\/\/www.nf8m.com\/nf8m\/wp-content\/uploads\/2018\/12\/beverage_relays-300x202.jpg\" alt=\"\" width=\"300\" height=\"202\" srcset=\"https:\/\/www.nf8m.com\/nf8m\/wp-content\/uploads\/2018\/12\/beverage_relays-300x202.jpg 300w, https:\/\/www.nf8m.com\/nf8m\/wp-content\/uploads\/2018\/12\/beverage_relays-768x518.jpg 768w, https:\/\/www.nf8m.com\/nf8m\/wp-content\/uploads\/2018\/12\/beverage_relays-1024x691.jpg 1024w, https:\/\/www.nf8m.com\/nf8m\/wp-content\/uploads\/2018\/12\/beverage_relays.jpg 1298w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>forward direction and one for the reverse. I also built a relay switching box that uses positive and negative phantom power (12 volts DC on the coax) to activate the relays, injected at the shack using a MFJ 4118 bias tee. With no voltage on the coax, the normal relay contacts switch the loop in, and positive and negative voltage switches the forward and reverse directions respectively.<\/p>\n<p>Initial evaluation shows that the antenna has quite good signal levels. Many S9 signals are heard without either an external preamp or the rig&#8217;s internal preamp. Due to its short length, it&#8217;s not particularly directive, though there is about a 2 S-unit (12 dB) front to back ratio on stations that are along the axis of the antenna. Stations broadside to the antenna are still heard, just not as strong.<\/p>\n<p>My hope is to be able to hear KL7 better and work the last state I need for 160 Worked-All-States this winter, as well as try to add to my Europe country count. It&#8217;ll get a checkout during the CWT this week and I plan to use it for the upcoming top band contests (Stew Perry and CQ 160).<\/p>\n<p>I&#8217;ll put some pictures up in the gallery soon.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A few years ago I built a shielded loop for receiving on 160 meters, but after attending W3LPL&#8217;s Contest University session on effective top band antennas, I thought about installing a better receive antenna. The loop does a decent job, with the 15 dB preamp I built to go along with it, but Frank pointed &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.nf8m.com\/nf8m\/beverage-antenna-project\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Beverage antenna project&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-397","post","type-post","status-publish","format-standard","hentry","category-equipment"],"_links":{"self":[{"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/posts\/397","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/comments?post=397"}],"version-history":[{"count":4,"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/posts\/397\/revisions"}],"predecessor-version":[{"id":402,"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/posts\/397\/revisions\/402"}],"wp:attachment":[{"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/media?parent=397"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/categories?post=397"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nf8m.com\/nf8m\/wp-json\/wp\/v2\/tags?post=397"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}