{"id":2714,"date":"2021-03-07T11:15:00","date_gmt":"2021-03-07T00:15:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2021\/03\/07\/exorcism-40-meter-rfi-problem-resolved\/"},"modified":"2025-07-21T13:50:12","modified_gmt":"2025-07-21T03:50:12","slug":"exorcism-40-meter-rfi-problem-resolved","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2021\/03\/07\/exorcism-40-meter-rfi-problem-resolved\/","title":{"rendered":"EXORCISM!   40 Meter RFI Problem Resolved"},"content":{"rendered":"<div class=\"separator\" style=\"clear: both; text-align: center;\"><a href=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1663.jpg\" style=\"margin-left: 1em; margin-right: 1em;\"><img loading=\"lazy\" decoding=\"async\" border=\"0\" data-original-height=\"1536\" data-original-width=\"2048\" height=\"300\" src=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1663.jpg\" width=\"400\" \/><\/a><\/div>\n<div class=\"separator\" style=\"clear: both; text-align: center;\">BEFORE<\/div>\n<p><b>David W. suggested I use my RTL-SDR dongle to look for the source of the 40 meter RFI that I have been mentioning. (It appears as an ugly stipe in the waterfall of my Hodgepodge transceiver.) So I fired up the RTL-SDR &#8212; there were the tell-tale spikes, spaced neatly every 50 kHz. The ARRL Handbook says this is typical of a switched power supply. Before I started patrolling the neighborhood with a tin-foil hat and a portable receiver, I decided to check my own house for any recently installed electronic devices. It didn&#8217;t take long &#8212; when I unplugged the new (mid-pandemic) treadmill the spikes disappeared. This treadmill was located about ten feet above my rigs, and between the rigs and the antenna. Duh. I should have thought of this earlier. Mystery solved. Thanks David. <\/b><\/p>\n<div class=\"separator\" style=\"clear: both; text-align: center;\"><a href=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1666.jpg\" style=\"margin-left: 1em; margin-right: 1em;\"><img loading=\"lazy\" decoding=\"async\" border=\"0\" data-original-height=\"1536\" data-original-width=\"2048\" height=\"300\" src=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1666.jpg\" width=\"400\" \/><\/a><\/div>\n<div class=\"separator\" style=\"clear: both; text-align: center;\">AFTER<\/div>\n<div class=\"separator\" style=\"clear: both; text-align: center;\"><\/div>\n<div class=\"separator\" style=\"clear: both; text-align: center;\"><a href=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1664.jpg\" style=\"margin-left: 1em; margin-right: 1em;\"><img loading=\"lazy\" decoding=\"async\" border=\"0\" data-original-height=\"1536\" data-original-width=\"2048\" height=\"300\" src=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1664.jpg\" width=\"400\" \/><\/a><\/div>\n<div class=\"separator\" style=\"clear: both; text-align: center;\"><\/div>\n<div class=\"separator\" style=\"clear: both; text-align: center;\"><a href=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1665.jpg\" style=\"margin-left: 1em; margin-right: 1em;\"><img loading=\"lazy\" decoding=\"async\" border=\"0\" data-original-height=\"1536\" data-original-width=\"2048\" height=\"300\" src=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2021\/03\/IMG-1665.jpg\" width=\"400\" \/><\/a><\/div>\n","protected":false},"excerpt":{"rendered":"<p>BEFORE David W. suggested I use my RTL-SDR dongle to look for the source of the 40 meter RFI that I have been mentioning. (It appears as an ugly stipe in the waterfall of my Hodgepodge transceiver.) So I fired up the RTL-SDR &#8212; there were the tell-tale spikes, spaced neatly every 50 kHz. The &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2021\/03\/07\/exorcism-40-meter-rfi-problem-resolved\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;EXORCISM!   40 Meter RFI Problem Resolved&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":2715,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[45,40],"tags":[],"class_list":["post-2714","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-interference","category-sdr"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2714","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=2714"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2714\/revisions"}],"predecessor-version":[{"id":2719,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2714\/revisions\/2719"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/2715"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=2714"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=2714"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=2714"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}