{"id":280,"date":"2014-09-14T12:08:05","date_gmt":"2014-09-14T11:08:05","guid":{"rendered":"http:\/\/www.eb3frn.net\/?p=280"},"modified":"2014-09-14T16:26:23","modified_gmt":"2014-09-14T15:26:23","slug":"cheap-and-easy-to-build-1296mhz-eme-feedhorn-for-offset-dishes","status":"publish","type":"post","link":"https:\/\/www.eb3frn.net\/?p=280","title":{"rendered":"Cheap and easy to build 1296MHz EME feedhorn for offset dishes"},"content":{"rendered":"<p>Recently I build a circular polarization feedhorn to try to do EME in 1296 MHz. The hint was that it have very easy to build and cheap. I was looking some designs based in ual mode septum designs from N2UO and RA3AQ but they not are easy to build for me. My idea has been use fireplace pipe\u00a0and a dielectric depolarizer.<\/p>\n<div id=\"attachment_281\" style=\"width: 635px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420.jpg\"><img aria-describedby=\"caption-attachment-281\" data-attachment-id=\"281\" data-permalink=\"https:\/\/www.eb3frn.net\/?attachment_id=281\" data-orig-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420.jpg\" data-orig-size=\"4896,3672\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;3.3&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;DSC-WX200&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;1410637847&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;4.45&quot;,&quot;iso&quot;:&quot;200&quot;,&quot;shutter_speed&quot;:&quot;0.0333333333333&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;6&quot;}\" data-image-title=\"1296 Dual mode feedhorn\" data-image-description=\"&lt;p&gt;1296 Dual mode feedhorn&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;1296 Dual mode feedhorn&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420-300x225.jpg\" data-large-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420-1024x768.jpg\" loading=\"lazy\" class=\"size-large wp-image-281\" src=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420-1024x768.jpg\" alt=\"1296 Dual mode feedhorn\" width=\"625\" height=\"468\" srcset=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420-1024x768.jpg 1024w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420-300x225.jpg 300w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01420-624x467.jpg 624w\" sizes=\"(max-width: 625px) 100vw, 625px\" \/><\/a><p id=\"caption-attachment-281\" class=\"wp-caption-text\">1296 Dual mode feedhorn<\/p><\/div>\n<p>To build the feehorn I have used fireplace inox pipe of 150mm and a galvanized reduction from 250 to 150mm. The dielectric depolarizer is a piece of Rogers Duriod 5880. To try to minimize the number of sma connectors, I used a small piece of Suhner .141 as a probe that will connect directly to the LNA saver switch.<\/p>\n<div id=\"attachment_282\" style=\"width: 635px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398.jpg\"><img aria-describedby=\"caption-attachment-282\" data-attachment-id=\"282\" data-permalink=\"https:\/\/www.eb3frn.net\/?attachment_id=282\" data-orig-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398.jpg\" data-orig-size=\"4896,3672\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;3.3&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;DSC-WX200&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;1410630372&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;4.45&quot;,&quot;iso&quot;:&quot;500&quot;,&quot;shutter_speed&quot;:&quot;0.0333333333333&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"Building the RX probe\" data-image-description=\"&lt;p&gt;Building the RX probe&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Building the RX probe&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398-300x225.jpg\" data-large-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398-1024x768.jpg\" loading=\"lazy\" class=\"size-large wp-image-282\" src=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398-1024x768.jpg\" alt=\"Building the RX probe\" width=\"625\" height=\"468\" srcset=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398-1024x768.jpg 1024w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398-300x225.jpg 300w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01398-624x467.jpg 624w\" sizes=\"(max-width: 625px) 100vw, 625px\" \/><\/a><p id=\"caption-attachment-282\" class=\"wp-caption-text\">Building the RX probe<\/p><\/div>\n<div id=\"attachment_284\" style=\"width: 635px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400.jpg\"><img aria-describedby=\"caption-attachment-284\" data-attachment-id=\"284\" data-permalink=\"https:\/\/www.eb3frn.net\/?attachment_id=284\" data-orig-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400.jpg\" data-orig-size=\"4896,3672\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;3.3&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;DSC-WX200&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;1410631435&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;4.45&quot;,&quot;iso&quot;:&quot;125&quot;,&quot;shutter_speed&quot;:&quot;0.0333333333333&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"RX port probe\" data-image-description=\"&lt;p&gt;RX port probe&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;RX port probe&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400-300x225.jpg\" data-large-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400-1024x768.jpg\" loading=\"lazy\" class=\"size-large wp-image-284\" src=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400-1024x768.jpg\" alt=\"RX port probe\" width=\"625\" height=\"468\" srcset=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400-1024x768.jpg 1024w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400-300x225.jpg 300w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01400-624x467.jpg 624w\" sizes=\"(max-width: 625px) 100vw, 625px\" \/><\/a><p id=\"caption-attachment-284\" class=\"wp-caption-text\">RX port probe<\/p><\/div>\n<div id=\"attachment_283\" style=\"width: 635px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406.jpg\"><img aria-describedby=\"caption-attachment-283\" data-attachment-id=\"283\" data-permalink=\"https:\/\/www.eb3frn.net\/?attachment_id=283\" data-orig-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406.jpg\" data-orig-size=\"4896,3672\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;3.3&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;DSC-WX200&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;1410632703&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;4.45&quot;,&quot;iso&quot;:&quot;500&quot;,&quot;shutter_speed&quot;:&quot;0.0333333333333&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"Feedhorn inside\" data-image-description=\"&lt;p&gt;Feedhorn inside&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Feedhorn inside&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406-300x225.jpg\" data-large-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406-1024x768.jpg\" loading=\"lazy\" class=\"size-large wp-image-283\" src=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406-1024x768.jpg\" alt=\"Feedhorn inside\" width=\"625\" height=\"468\" srcset=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406-1024x768.jpg 1024w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406-300x225.jpg 300w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01406-624x467.jpg 624w\" sizes=\"(max-width: 625px) 100vw, 625px\" \/><\/a><p id=\"caption-attachment-283\" class=\"wp-caption-text\">Feedhorn inside<\/p><\/div>\n<p>In the TX port I used a standard N connector. I measured the RL in the lab, but have to measure the RL in the dish for this reason the bottom plate not is soldered yet, it is glued using metalic tape, until the RL is adjusted on the dish.<\/p>\n<div id=\"attachment_286\" style=\"width: 635px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411.jpg\"><img aria-describedby=\"caption-attachment-286\" data-attachment-id=\"286\" data-permalink=\"https:\/\/www.eb3frn.net\/?attachment_id=286\" data-orig-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411.jpg\" data-orig-size=\"4896,3672\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;3.3&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;DSC-WX200&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;1410637595&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;4.45&quot;,&quot;iso&quot;:&quot;800&quot;,&quot;shutter_speed&quot;:&quot;0.0666666666667&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"DSC01411\" data-image-description=\"&lt;p&gt;Measuring return loss&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Measuring return loss&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411-300x225.jpg\" data-large-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411-1024x768.jpg\" loading=\"lazy\" class=\"size-large wp-image-286\" src=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411-1024x768.jpg\" alt=\"Measuring return loss\" width=\"625\" height=\"468\" srcset=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411-1024x768.jpg 1024w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411-300x225.jpg 300w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC01411-624x467.jpg 624w\" sizes=\"(max-width: 625px) 100vw, 625px\" \/><\/a><p id=\"caption-attachment-286\" class=\"wp-caption-text\">Measuring return loss<\/p><\/div>\n<div id=\"attachment_290\" style=\"width: 635px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281.jpg\"><img aria-describedby=\"caption-attachment-290\" data-attachment-id=\"290\" data-permalink=\"https:\/\/www.eb3frn.net\/?attachment_id=290\" data-orig-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281.jpg\" data-orig-size=\"3672,4896\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;8&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;DSC-WX200&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;1400415170&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;4.45&quot;,&quot;iso&quot;:&quot;100&quot;,&quot;shutter_speed&quot;:&quot;0.0025&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"Feedhon on the dish\" data-image-description=\"&lt;p&gt;Feedhon on the dish&lt;\/p&gt;\n\" data-image-caption=\"&lt;p&gt;Feedhon on the dish&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281-225x300.jpg\" data-large-file=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281-768x1024.jpg\" loading=\"lazy\" class=\"size-large wp-image-290\" src=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281-768x1024.jpg\" alt=\"Feedhon on the dish\" width=\"625\" height=\"833\" srcset=\"https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281-768x1024.jpg 768w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281-225x300.jpg 225w, https:\/\/www.eb3frn.net\/wp-content\/uploads\/2014\/09\/DSC011281-624x832.jpg 624w\" sizes=\"(max-width: 625px) 100vw, 625px\" \/><\/a><p id=\"caption-attachment-290\" class=\"wp-caption-text\">Feedhon on the dish<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Recently I build a circular polarization feedhorn to try to do EME in 1296 MHz. The hint was that it have very easy to build and cheap. I was looking some designs based in ual mode septum designs from N2UO and RA3AQ but they not are easy to build for me. My idea has been [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true},"categories":[1,4],"tags":[],"jetpack_featured_media_url":"","jetpack_publicize_connections":[],"jetpack_shortlink":"https:\/\/wp.me\/p31CYx-4w","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=\/wp\/v2\/posts\/280"}],"collection":[{"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=280"}],"version-history":[{"count":7,"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=\/wp\/v2\/posts\/280\/revisions"}],"predecessor-version":[{"id":294,"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=\/wp\/v2\/posts\/280\/revisions\/294"}],"wp:attachment":[{"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=280"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=280"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.eb3frn.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=280"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}