{"id":13800,"date":"2025-04-04T09:54:33","date_gmt":"2025-04-04T04:24:33","guid":{"rendered":"https:\/\/johnsonfrancis.org\/techworld\/?p=13800"},"modified":"2025-04-04T09:57:16","modified_gmt":"2025-04-04T04:27:16","slug":"enjoyed-the-very-low-noise-level-on-40m-but","status":"publish","type":"post","link":"https:\/\/johnsonfrancis.org\/techworld\/enjoyed-the-very-low-noise-level-on-40m-but\/","title":{"rendered":"Enjoyed the very low noise level on 40m, but&#8230;"},"content":{"rendered":"<iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/UWKBwKYr1o4?si=We13fcBXsP5p7WWY\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n\n<p class=\"wp-block-paragraph\">Fed up with the S9 or more noise in my radio most of the time, I was thinking of buying battery and testing whether working on pure DC would help me. It was then that this S1 level of noise appeared in my radio at about 9.05 am local time. I was able to hear all stations with &#8216;FM&#8217; quality. When the operator was releasing the PTT, it was nice to see the S meter needle go all the way down to S1 from S9. So I was sure that it is not the switch mode power supply which I use for the radio which is producing the noise. If I invest in a battery, it will not help me reduce the noise level. Of course, it will give backup during power failure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But the happiness did not last long. Just as the noise had went off suddenly, it came back suddenly at about 9.10 am local time. Now you can see that the swing of the S meter needle is only from S9 to S7. I have muted the audio in the video clips to avoid distraction to the narration. Still I am happy to get a confirmation that my SMPS is not the culprit, nor anything inside my shack, as everything was on as usual. The noise is coming from some device in the neighbourhood, over which I have absolutely no control and has to accept it.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Fed up with the S9 or more noise in my radio most of the time, I was thinking of buying battery and testing whether working on pure DC would help me. It was then that this S1 level of noise appeared in my radio at about 9.05 am local time. I was able to hear [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":13803,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-13800","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>Enjoyed the very low noise level on 40m, but... - 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\/enjoyed-the-very-low-noise-level-on-40m-but\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Enjoyed the very low noise level on 40m, but... - Johnson&#039;s Techworld\" \/>\n<meta property=\"og:description\" content=\"Fed up with the S9 or more noise in my radio most of the time, I was thinking of buying battery and testing whether working on pure DC would help me. 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