{"id":8610,"date":"2024-03-24T04:55:13","date_gmt":"2024-03-23T23:25:13","guid":{"rendered":"https:\/\/johnsonfrancis.org\/techworld\/?p=8610"},"modified":"2024-03-24T05:18:33","modified_gmt":"2024-03-23T23:48:33","slug":"source-of-rfi-pinpointed","status":"publish","type":"post","link":"https:\/\/johnsonfrancis.org\/techworld\/source-of-rfi-pinpointed\/","title":{"rendered":"Source of RFI Pinpointed!"},"content":{"rendered":"<p><iframe loading=\"lazy\" title=\"YouTube video player\" src=\"https:\/\/www.youtube.com\/embed\/J_QHEjdnOOg?si=VzFdyd6Xkhot7GCs\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>In an earlier post, I had mentioned that <a href=\"https:\/\/johnsonfrancis.org\/techworld\/eureka-source-of-major-rfi-identified\/\">two strong bands of radio frequency interference<\/a> noted on the waterfall display in my radio was due to my computer UPS. It was a surprise finding today that it is not so. I had noted that the RFI disappeared when the UPS was switched off, only to reappear when it is switched on. This led to my earlier presumption. Actually the culprit was a small SMPS adaptor which I use to power an amplispeaker for my computer. The small SMPS was connected to an extension board from the output of the computer UPS. So, switching off the UPS naturally switches off this SMPS as well. That was how I initially thought that the UPS was the culprit!<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8614\" src=\"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2024\/03\/Source-of-RFI-Pinpointed.jpg\" alt=\"\" width=\"1202\" height=\"675\" srcset=\"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2024\/03\/Source-of-RFI-Pinpointed.jpg 1202w, https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2024\/03\/Source-of-RFI-Pinpointed-300x168.jpg 300w, https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2024\/03\/Source-of-RFI-Pinpointed-1024x575.jpg 1024w, https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2024\/03\/Source-of-RFI-Pinpointed-768x431.jpg 768w\" sizes=\"auto, (max-width: 1202px) 100vw, 1202px\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In an earlier post, I had mentioned that two strong bands of radio frequency interference noted on the waterfall display in my radio was due to my computer UPS. It was a surprise finding today that it is not so. I had noted that the RFI disappeared when the UPS was switched off, only to [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":8614,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-8610","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-amateur-radio-ham-radio"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.8 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Source of RFI Pinpointed! - Johnson&#039;s Techworld<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/johnsonfrancis.org\/techworld\/source-of-rfi-pinpointed\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Source of RFI Pinpointed! - Johnson&#039;s Techworld\" \/>\n<meta property=\"og:description\" content=\"In an earlier post, I had mentioned that two strong bands of radio frequency interference noted on the waterfall display in my radio was due to my computer UPS. It was a surprise finding today that it is not so. I had noted that the RFI disappeared when the UPS was switched off, only to [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/johnsonfrancis.org\/techworld\/source-of-rfi-pinpointed\/\" \/>\n<meta property=\"og:site_name\" content=\"Johnson&#039;s Techworld\" \/>\n<meta property=\"article:published_time\" content=\"2024-03-23T23:25:13+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-03-23T23:48:33+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2024\/03\/Source-of-RFI-Pinpointed.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1202\" \/>\n\t<meta property=\"og:image:height\" content=\"675\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Johnson Francis\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Johnson Francis\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/source-of-rfi-pinpointed\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/source-of-rfi-pinpointed\\\/\"},\"author\":{\"name\":\"Johnson Francis\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#\\\/schema\\\/person\\\/6201c843e80ccd3578e6196b1d007027\"},\"headline\":\"Source of RFI Pinpointed!\",\"datePublished\":\"2024-03-23T23:25:13+00:00\",\"dateModified\":\"2024-03-23T23:48:33+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/source-of-rfi-pinpointed\\\/\"},\"wordCount\":129,\"publisher\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#\\\/schema\\\/person\\\/6201c843e80ccd3578e6196b1d007027\"},\"image\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/source-of-rfi-pinpointed\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2024\\\/03\\\/Source-of-RFI-Pinpointed.jpg\",\"articleSection\":[\"Amateur Radio (Ham Radio)\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/source-of-rfi-pinpointed\\\/\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/source-of-rfi-pinpointed\\\/\",\"name\":\"Source of RFI Pinpointed! 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Originally licensed as VU2JFP with Grade 1 license in 1985. Upgraded to Advanced Grade in 1988 and was allotted new callsign to VU2JO\",\"sameAs\":[\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\",\"https:\\\/\\\/www.youtube.com\\\/@johnsonstechworld\\\/\"],\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/author\\\/jf\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Source of RFI Pinpointed! - Johnson&#039;s Techworld","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/johnsonfrancis.org\/techworld\/source-of-rfi-pinpointed\/","og_locale":"en_US","og_type":"article","og_title":"Source of RFI Pinpointed! - Johnson&#039;s Techworld","og_description":"In an earlier post, I had mentioned that two strong bands of radio frequency interference noted on the waterfall display in my radio was due to my computer UPS. 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