{"id":11143,"date":"2014-10-22T06:00:20","date_gmt":"2014-10-22T10:00:20","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=11143"},"modified":"2014-10-22T06:01:19","modified_gmt":"2014-10-22T10:01:19","slug":"uncovering-the-wullenweber-elephant-cages","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2014\/10\/uncovering-the-wullenweber-elephant-cages\/","title":{"rendered":"Uncovering Wullenweber&#8217;s &#8220;Elephant Cages&#8221;"},"content":{"rendered":"<p><a href=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-11144\" src=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB.jpg\" alt=\"800px-CDAA_Elmendorf_AFB\" width=\"800\" height=\"612\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB.jpg 800w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB-300x229.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/a>Many thanks to <em>SWLing Post<\/em> reader, Bill Patalon, for sharing <a title=\"Gizmodo\" href=\"http:\/\/gizmodo.com\/this-electronic-stonehenge-once-divined-the-secrets-of-1647210382\" target=\"_blank\">this article via Gizmodo<\/a>:<\/p>\n<blockquote>\n<p class=\"first-text\" data-textannotation-id=\"1e4e0c9a3aa08f5c7ac335dc791e6376\">In the early days of electronic espionage, the US intelligence community didn&#8217;t have the benefit of all-seeing spy satellites\u2014it had to intercept and interpret high-frequency radio waves transmitted by the Soviet Union. To do so, the Americans relied on a network of mysterious structures whose real purpose was kept highly classified throughout the Cold War.<\/p>\n<p data-textannotation-id=\"0d2cb2993b019da0ce4a6fc523329d3a\">Nicknamed &#8220;Elephant Cages&#8221; by outside observers, these structures were actually high-frequency antenna arrays, part of the US military&#8217;s AN\/FLR-9 &#8220;Iron Horse&#8221; system. These arrays, commonly known as &#8220;Wullenweber&#8221; antennas\u2014and named after German WWII scientist, Dr. Hans Rindfleisch was Wullenwe<strong>v<\/strong>er\u2014are a type of Circularly Disposed Antenna Array (CDAA). They can be used for a variety of purposes from intelligence gathering and identifying high-value targets to navigation and search and rescue operations.<\/p>\n<p data-textannotation-id=\"0d2cb2993b019da0ce4a6fc523329d3a\">Each elephant cage consisted of an inner ring of antennas tuned for high frequency waves surrounded by one or more outer rings tuned for lower frequencies. These antennas would listen for HF radio waves bouncing off the ionosphere (which is what also allows HF radios to communicate beyond the horizon) and triangulate the precise location of the signal&#8217;s source.<\/p>\n<\/blockquote>\n<p data-textannotation-id=\"0d2cb2993b019da0ce4a6fc523329d3a\"><a title=\"Gizmodo\" href=\"http:\/\/gizmodo.com\/this-electronic-stonehenge-once-divined-the-secrets-of-1647210382\" target=\"_blank\">Click here to continue reading at Gizmodo&#8230;<\/a><\/p>\n<p data-textannotation-id=\"0d2cb2993b019da0ce4a6fc523329d3a\">If you&#8217;d like to read more about &#8220;Elephant Cages&#8221; check out the following links:<\/p>\n<ul>\n<li data-textannotation-id=\"0d2cb2993b019da0ce4a6fc523329d3a\"><a title=\"Download as a PDF\" href=\"http:\/\/www.premium-rx.org\/ref\/wullenweber.pdf\" target=\"_blank\">Download the Technical Manual for the\u00a0AN\/FLR-9(V7)\/(V8)<\/a><\/li>\n<li data-textannotation-id=\"0d2cb2993b019da0ce4a6fc523329d3a\"><a href=\"http:\/\/en.wikipedia.org\/wiki\/Wullenweber\" target=\"_blank\">This article on WikiPedia<\/a><\/li>\n<li data-textannotation-id=\"0d2cb2993b019da0ce4a6fc523329d3a\"><a href=\"http:\/\/www.navy-radio.com\/frd10.htm\" target=\"_blank\">This article on Navy-Radio.com<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Many thanks to SWLing Post reader, Bill Patalon, for sharing this article via Gizmodo: In the early days of electronic espionage, the US intelligence community didn&#8217;t have the benefit of all-seeing spy satellites\u2014it had to intercept and interpret high-frequency radio waves transmitted by the Soviet Union. To do so, the Americans relied on a network [&hellip;]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[3,288,43],"tags":[3339,3338,752,3067,3335,3336,3337],"class_list":["post-11143","post","type-post","status-publish","format-standard","hentry","category-news","category-radio-history","category-shortwave-radio","tag-bill-patalon","tag-circular-receiving-antennas","tag-cold-war","tag-cold-war-radio","tag-elephant-cages","tag-wullenweber","tag-wullenweber-antennas"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-2TJ","jetpack-related-posts":[{"id":11192,"url":"https:\/\/swling.com\/blog\/2014\/10\/tearing-down-an-elephant-cage\/","url_meta":{"origin":11143,"position":0},"title":"Tearing down an Elephant Cage","author":"Thomas","date":"October 26, 2014","format":false,"excerpt":"This past week, I posted a couple of articles about\u00a0Wullenweber\u00a0antennas (a.k.a. \"Elephant Cages\"). Many thanks to Andrea Borgnino who shares this article by Joseph Trevithick via Medium.com: The U.S. Air Force Is Tearing Down a Giant Spy Antenna: \u2019Elephant cages\u2019 are a dying breed The U.S. Air Force has started\u2026","rel":"","context":"In &quot;News&quot;","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"800px-CDAA_Elmendorf_AFB","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB.jpg?resize=525%2C300 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/800px-CDAA_Elmendorf_AFB.jpg?resize=700%2C400 2x"},"classes":[]},{"id":11213,"url":"https:\/\/swling.com\/blog\/2014\/10\/san-diego-elephant-cage-scheduled-for-demolition\/","url_meta":{"origin":11143,"position":1},"title":"San Diego Elephant Cage scheduled for demolition","author":"Thomas","date":"October 28, 2014","format":false,"excerpt":"On the topic of Wullenweber antennas, SWLing Post reader, Mike, points to this article on U-T San Diego's website: Navy's mysterious 'elephant cage' retired:\u00a0Cold War-era structure a visual landmark on Silver Strand Beachgoers will say goodbye this month to the \u201celephant cage\u201d -- the mysterious metal structure that has graced\u2026","rel":"","context":"In &quot;News&quot;","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"SanDiego","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/SanDiego.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/SanDiego.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/SanDiego.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":24871,"url":"https:\/\/swling.com\/blog\/2017\/04\/paul-remembers-the-flr-9-elephant-cage-in-misawa-japan\/","url_meta":{"origin":11143,"position":2},"title":"Paul remembers the FLR-9 &#8220;Elephant Cage&#8221; in Misawa Japan","author":"Thomas","date":"April 1, 2017","format":false,"excerpt":"Many thanks to SWLing Post contributor, Paul, who writes: I was a morse intercept operator in the USAF in the late 1960s. I have a nice picture of a FLR-9 at Misawa Japan (now gone I think): I was at Misawa from 68-70 in the USAF Security Service. I copied\u2026","rel":"","context":"In &quot;News&quot;","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/Copy-of-Miisawa-1-e1490707808454.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/Copy-of-Miisawa-1-e1490707808454.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/Copy-of-Miisawa-1-e1490707808454.jpg?resize=525%2C300 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/Copy-of-Miisawa-1-e1490707808454.jpg?resize=700%2C400 2x"},"classes":[]},{"id":11167,"url":"https:\/\/swling.com\/blog\/2014\/10\/mike-recalls-visiting-the-original-wullenweber-test-site\/","url_meta":{"origin":11143,"position":3},"title":"Mike recalls visiting the original Wullenweber test site","author":"Thomas","date":"October 24, 2014","format":false,"excerpt":"In response to our post Uncovering Wullenweber\u2019s \u201cElephant Cages,\u201d Mike comments: Sometime back around 2005-2009, I was doing maintenance on a NOAA climate station near Bondville, IL, and noticed several tall utility poles in the distance. As I figured they looked suspiciously like an antenna array, I asked the site\u2026","rel":"","context":"In &quot;News&quot;","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"Illinois","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/Illinois.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/Illinois.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/10\/Illinois.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":47651,"url":"https:\/\/swling.com\/blog\/2021\/02\/the-last-elephant-cage-is-a-fascinating-nsa-documentary-about-the-monolithic-flr-9-antenna-system\/","url_meta":{"origin":11143,"position":4},"title":"&#8220;The Last Elephant Cage&#8221; is a fascinating NSA documentary about the monolithic FLR-9 antenna system","author":"Thomas","date":"February 5, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, Andrea Borgnino (IW0HK), who shares the following video--a 15 minute NSA documentary--about the FLR-9 \"Elephant Cage\" antenna in Anchorage, Alaska. https:\/\/youtu.be\/uh88Y2_33GI Click here to view on YouTube.","rel":"","context":"In &quot;Antennas&quot;","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/02\/FLR-9-Elephant-cage.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/02\/FLR-9-Elephant-cage.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/02\/FLR-9-Elephant-cage.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/02\/FLR-9-Elephant-cage.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/02\/FLR-9-Elephant-cage.jpg?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":22705,"url":"https:\/\/swling.com\/blog\/2016\/12\/1940-pearl-harbor-qsl-card\/","url_meta":{"origin":11143,"position":5},"title":"1940 Pearl Harbor QSL card","author":"Thomas","date":"December 7, 2016","format":false,"excerpt":"Many thanks to SWLing Post contributor, Bill Patalon, who shares the following QSL card\u00a0via Twitter: https:\/\/twitter.com\/PrivateBrief\/status\/806189384244596736 Thank you, Bill!","rel":"","context":"In &quot;Ham Radio&quot;","block_context":{"text":"Ham Radio","link":"https:\/\/swling.com\/blog\/category\/ham-radio\/"},"img":{"alt_text":"pearl-harbor-qsl","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/12\/Pearl-Harbor-QSL.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/12\/Pearl-Harbor-QSL.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/12\/Pearl-Harbor-QSL.jpg?resize=525%2C300 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/12\/Pearl-Harbor-QSL.jpg?resize=700%2C400 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/11143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=11143"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/11143\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=11143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=11143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=11143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}