{"id":5978,"date":"2011-03-06T22:29:00","date_gmt":"2011-03-06T11:29:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2011\/03\/06\/crystal-radio-sleuthing\/"},"modified":"2025-07-21T19:58:04","modified_gmt":"2025-07-21T09:58:04","slug":"crystal-radio-sleuthing","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2011\/03\/06\/crystal-radio-sleuthing\/","title":{"rendered":"Crystal Radio Sleuthing"},"content":{"rendered":"<p><a onblur=\"try {parent.deselectBloggerImageGracefully();} catch(e) {}\" href=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2011\/03\/P1010246.jpg\"><img decoding=\"async\" style=\"display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 400px; height: 299px;\" src=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2011\/03\/P1010246.jpg\" alt=\"\" id=\"BLOGGER_PHOTO_ID_5581098193580037618\" border=\"0\" \/><\/a><span style=\"font-size:130%;\"><span style=\"font-weight: bold;\">As part of my effort to stamp out broadcast interference to the SolderSmoke podcast, this weekend I reassembled the crystal radio that Billy and I had built in London. It is REAL simple: Just a parallel LC circuit with a germanium diode detector and some high impedance phones. (I also put a chunk of galena and a cat&#8217;s whisker on the board &#8212; that&#8217;s for when I get the urge to form my own PN junctions.) As expected, I immediately heard two AM broadcast stations: WFAX 5 kw 1220 kHz (religious) and WUST 20 kw 1120 kHz AM (mostly foreign language). I found out the hard way that these stations reduce power at night: I was bragging to my wife about the EXCELLENT reception I&#8217;d been getting on the crystal set, but when, after dinner, I brought her into the shack for a demonstration, she could barely hear anything. Oh well&#8230;<\/span><\/p>\n<p><span style=\"font-weight: bold;\">But here&#8217;s a surprise: These are NOT the stations that are getting into the podcast! With the crystal radio in operation, I did some audacity recording and then quickly checked to see if the breakthrough sounded like what they were playing on WFAX and WUST. NO! The breakthrough was ZZ Top! I&#8217;m guessing that the breakthrough was from an FM broadcaster. I note that the length of the cord to the microphone would seems like it would be a nice antenna for the FM broadcast band&#8230; What do you guys think? <\/span><\/p>\n<p><span style=\"font-weight: bold;\">Whatever the source, I think I have taken care of the problem. I got big ferrite toroid core and wrapped about ten turns of the mic cable through it. No more broadcast breakthrough. <\/span><br \/><span style=\"font-weight: bold;\"> <\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>As part of my effort to stamp out broadcast interference to the SolderSmoke podcast, this weekend I reassembled the crystal radio that Billy and I had built in London. It is REAL simple: Just a parallel LC circuit with a germanium diode detector and some high impedance phones. (I also put a chunk of galena &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2011\/03\/06\/crystal-radio-sleuthing\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Crystal Radio Sleuthing&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":5979,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[108,49],"tags":[],"class_list":["post-5978","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-crystal-radio","category-soldersmoke-podcast"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/5978","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/comments?post=5978"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/5978\/revisions"}],"predecessor-version":[{"id":5980,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/5978\/revisions\/5980"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/5979"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=5978"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=5978"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=5978"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}