{"id":40723,"date":"2019-11-21T08:05:58","date_gmt":"2019-11-21T12:05:58","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=40723"},"modified":"2019-11-21T08:05:58","modified_gmt":"2019-11-21T12:05:58","slug":"am-radio-from-a-hand-wound-coil-and-an-oxidized-british-penny","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2019\/11\/am-radio-from-a-hand-wound-coil-and-an-oxidized-british-penny\/","title":{"rendered":"AM radio from a hand-wound coil\u00a0and an oxidized British penny"},"content":{"rendered":"<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Screen-Shot-2019-11-21-at-07.06.18.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-40724\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Screen-Shot-2019-11-21-at-07.06.18.jpg\" alt=\"\" width=\"800\" height=\"409\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Screen-Shot-2019-11-21-at-07.06.18.jpg 800w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Screen-Shot-2019-11-21-at-07.06.18-300x153.jpg 300w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Screen-Shot-2019-11-21-at-07.06.18-768x393.jpg 768w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/Screen-Shot-2019-11-21-at-07.06.18-624x319.jpg 624w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/a><\/p>\n<p>Many thanks to\u00a0<em>SWLing Post<\/em>\u00a0contributor,\u00a0<a href=\"http:\/\/w4.vp9kf.com\/\" target=\"_blank\" rel=\"noopener noreferrer\">Paul Evans<\/a>, who shares the following video and article <a href=\"https:\/\/hackaday.com\/2019\/11\/15\/a-radio-for-the-apocalypse\/\" target=\"_blank\" rel=\"noopener noreferrer\">via <strong>Hackaday<\/strong><\/a>:<\/p>\n<p><span class=\"embed-youtube\" style=\"text-align:center; display: block;\"><iframe loading=\"lazy\" class=\"youtube-player\" width=\"625\" height=\"352\" src=\"https:\/\/www.youtube.com\/embed\/bUMXc6fi7yk?version=3&#038;rel=1&#038;showsearch=0&#038;showinfo=1&#038;iv_load_policy=1&#038;fs=1&#038;hl=en-US&#038;autohide=2&#038;wmode=transparent\" allowfullscreen=\"true\" style=\"border:0;\" sandbox=\"allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox\"><\/iframe><\/span><\/p>\n<blockquote><p>There\u2019s been a spate of apocalypse related articles over the last few weeks, but when I saw <a href=\"https:\/\/www.youtube.com\/watch?v=bUMXc6fi7yk\" target=\"_blank\" rel=\"noopener noreferrer\">an AM radio made from a hand-wound coil<\/a>\u00a0and an oxidized British penny, I couldn\u2019t help but be impressed. We\u2019ve covered\u00a0<a href=\"https:\/\/hackaday.com\/2016\/04\/21\/hacking-when-it-counts-pow-canteen-radios\/\">foxhole radios<\/a>, stereotypical radios that are cobbled together from found parts during wartime.<\/p>\n<p>This example uses a variable capacitor for tuning, but that\u2019s technically optional. All that\u2019s really needed is a coil and something to work as a diode. Surprisingly, copper oxide is a semiconductor, and the surface oxidation on a penny is enough to form a rudimentary diode.[&#8230;]<\/p>\n<p style=\"text-align: center;\"><strong><a href=\"https:\/\/hackaday.com\/2019\/11\/15\/a-radio-for-the-apocalypse\/\" target=\"_blank\" rel=\"noopener noreferrer\">Click here to read the full article at Hackaday.<\/a><\/strong><\/p>\n<\/blockquote>\n<p>Thanks for sharing this, Paul. I absolutely love simple receivers like this one. In the past, I&#8217;ve built several crystal radios and had great success hearing local AM broadcasters. Indeed, the very first kit I ever built was a crystal radio, then later a foxhole style receiver.<\/p>\n<p><strong><em>Post<\/em> readers:<\/strong> Have you ever built a radio similar to this one that uses an oxidized penny?\u00a0 Please comment!<\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/swling.com\/blog\/tag\/crystal-radio\/\">Click here to read posts from our archives that focus on crystal radios<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Many thanks to\u00a0SWLing Post\u00a0contributor,\u00a0Paul Evans, who shares the following video and article via Hackaday: There\u2019s been a spate of apocalypse related articles over the last few weeks, but when I saw an AM radio made from a hand-wound coil\u00a0and an oxidized British penny, I couldn\u2019t help but be impressed. We\u2019ve covered\u00a0foxhole radios, stereotypical radios that [&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":[373,627,3],"tags":[617,3354,7864,8147],"class_list":["post-40723","post","type-post","status-publish","format-standard","hentry","category-am","category-how-to","category-news","tag-crystal-radio","tag-hackaday","tag-paul-evans-w4-vp9kf","tag-penny-crystal-radio"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-aAP","jetpack-related-posts":[{"id":43684,"url":"https:\/\/swling.com\/blog\/2020\/06\/credit-card-crystal-radio\/","url_meta":{"origin":40723,"position":0},"title":"Credit Card Crystal Radio","author":"Thomas","date":"June 3, 2020","format":false,"excerpt":"Many thanks to SWLing Post contributor, Paul Evans, who shares this article from Hackaday that highlights a crystal radio built completely on a smart chip credit card by Billy Cheung. Hackaday notes: This is possible because the smart chip on many credit cards contains a diode. It\u2019s then a simple\u2026","rel":"","context":"In &quot;How To&quot;","block_context":{"text":"How To","link":"https:\/\/swling.com\/blog\/category\/how-to\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/06\/crystal-radio-credit-card-e1591183584962.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/06\/crystal-radio-credit-card-e1591183584962.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/06\/crystal-radio-credit-card-e1591183584962.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/06\/crystal-radio-credit-card-e1591183584962.jpeg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":41103,"url":"https:\/\/swling.com\/blog\/2019\/12\/video-tube-radio-transmitter-designs-from-the-1920s\/","url_meta":{"origin":40723,"position":1},"title":"Video: Tube radio transmitter designs from the 1920s","author":"Thomas","date":"December 7, 2019","format":false,"excerpt":"Many thanks to SWLing Post contributor, Paul Evans (W4\/VP9KF), who shares the following article from Hackaday: The origin of the term \u201cbreadboard\u201d comes from an amusing past when wooden bread boards were swiped from kitchens and used as a canvas for radio hobbyists to roll homemade capacitors, inductors, and switches.\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\/2019\/12\/Antique-Radio.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/12\/Antique-Radio.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/12\/Antique-Radio.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/12\/Antique-Radio.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":38796,"url":"https:\/\/swling.com\/blog\/2019\/08\/hackaday-looks-back-at-the-venerable-rtl-sdr\/","url_meta":{"origin":40723,"position":2},"title":"Hackaday looks back at the venerable RTL-SDR","author":"Thomas","date":"August 3, 2019","format":false,"excerpt":"Many thanks to SWLing Post contributor, Paul Evans (W4\/VP9KF), who shares the following article from Hackaday: Before swearing my fealty to the Jolly Wrencher, I wrote for several other sites, creating more or less the same sort of content I do now. In fact, the topical overlap was enough that\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\/RTL-SDR-ADS-B-Rasperry-Pi-PiAware-1024x631.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/RTL-SDR-ADS-B-Rasperry-Pi-PiAware-1024x631.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/03\/RTL-SDR-ADS-B-Rasperry-Pi-PiAware-1024x631.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":38566,"url":"https:\/\/swling.com\/blog\/2019\/07\/a-very-exciting-radio\/","url_meta":{"origin":40723,"position":3},"title":"A very \u201cexciting\u201d radio!","author":"Thomas","date":"July 19, 2019","format":false,"excerpt":"Many thanks to SWLing Post contributor, Paul W4\/VP9KFPaul W4\/VP9KF, who writes: A very exciting radio! One that depends on excited atoms, of a sort... (Source: Hackaday) The basic technology of radio hasn\u2019t changed much since an Italian marquis first blasted telegraph messages across the Atlantic using a souped-up spark plug\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\/2019\/07\/32664D29-3A1C-4E05-A5B9-7928CA2C81BF-750x1024.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/07\/32664D29-3A1C-4E05-A5B9-7928CA2C81BF-750x1024.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/07\/32664D29-3A1C-4E05-A5B9-7928CA2C81BF-750x1024.jpeg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":43043,"url":"https:\/\/swling.com\/blog\/2020\/04\/radio-waves-am-fm-in-teslas-odd-crosleys-cw-club-membership-on-the-rise-and-2020-contest-university-is-free\/","url_meta":{"origin":40723,"position":4},"title":"Radio Waves: AM\/FM in Teslas, Odd Crosleys, CW Club Membership on the Rise, and 2020 Contest University is Free","author":"Thomas","date":"April 29, 2020","format":false,"excerpt":"Radio Waves:\u00a0 Stories Making Waves in the World of Radio Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest\u00a0SWLing Post\u00a0readers.\u00a0 To that end:\u00a0Welcome to the\u00a0SWLing Post\u2019s Radio Waves, a\u2026","rel":"","context":"In &quot;AM&quot;","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Crosley-Dial-1024x678.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Crosley-Dial-1024x678.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Crosley-Dial-1024x678.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":51594,"url":"https:\/\/swling.com\/blog\/2022\/01\/guest-post-crystal-radios-construction-listening-and-contesting\/","url_meta":{"origin":40723,"position":5},"title":"Guest Post: Crystal Radios \u2013 Construction, Listening, and Contesting","author":"Thomas","date":"January 24, 2022","format":false,"excerpt":"Many thanks to SWLing Post contributor, David Day (N1DAY), for sharing the following guest post: Crystal Radios \u2013 Construction, Listening, and Contesting By David Day \u2013 N1DAY The date was November 2, 1920 and the world was about to change forever when radio station KDKA out of Pittsburgh PA made\u2026","rel":"","context":"In &quot;AM&quot;","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/01\/N1DAY-Crystal-Case.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/01\/N1DAY-Crystal-Case.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/01\/N1DAY-Crystal-Case.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/01\/N1DAY-Crystal-Case.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/01\/N1DAY-Crystal-Case.jpeg?resize=1050%2C600&ssl=1 3x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/40723","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=40723"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/40723\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=40723"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=40723"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=40723"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}