{"id":16761,"date":"2026-03-30T14:20:49","date_gmt":"2026-03-30T08:50:49","guid":{"rendered":"https:\/\/johnsonfrancis.org\/techworld\/?p=16761"},"modified":"2026-03-31T08:47:52","modified_gmt":"2026-03-31T03:17:52","slug":"venturing-into-homebrewing-lmr-sdr-1-1","status":"publish","type":"post","link":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/","title":{"rendered":"Venturing into homebrewing LMR SDR 1.1"},"content":{"rendered":"<iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/j0TtvndRbq4?si=_pgFwmZfJmQcoACl\" 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\n<p class=\"wp-block-paragraph\">I heard VU3AVE on 40m with good quality audio when he was using a homebrew LMR SDR 1.1 with a homebrew 30W linear amplifier. That made me think of trying to homebrew one and ordered a PCB with Si5351 pre-soldered and three other ICs which are difficult to procure locally. VU3GEX helped me to source an unused kit from VU3FVX which will save me a lot of trouble procuring each and every individual component online or offline. Meanwhile I thought of learning a bit about the LMR SDR 1.1 from the website of <a href=\"https:\/\/www.ye3cif.com\/lmr-sdr-transceiver-10-160-meter-band\/\" type=\"link\" id=\"https:\/\/www.ye3cif.com\/lmr-sdr-transceiver-10-160-meter-band\/\">YE3CIF<\/a>. Bottleneck there is the language, which is not known to me! So I am using Google Translate to get an idea about it and giving it here for the benefit of others who might be interested in homebrewing LMR SDR. An English language site with good information is there by <a href=\"https:\/\/f5npv.wordpress.com\/homebrew-sdr-trx\/\" type=\"link\" id=\"https:\/\/f5npv.wordpress.com\/homebrew-sdr-trx\/\">F5NPV<\/a> (Currently operating as V85NPV).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">LMR SDR can give a power output of about 10-50 mW and needs an external RF power amplifier. It also needs a desktop computer with good stereo soundcard for processing. The clock generator is Si5351 and microcontroller is Arduino Nano in LMR SDR 1.1. A different microcontroller is used in the latest 1.7 version. I thought of trying out the 1.1 version which has been built successfully by several hams in my region. PowerSDR software to be installed in a desktop running Windows is available for download from the webpage of YE3CIF. LMR SDR 1.1 needs a 16 x 2 LCD display for showing the correctness of installation. If the installation is correct, the LCD will display the working frequency as on PowerSDR software in your desktop. Schematic is available online for easy reference during the build. Expecting a lot of support from all who have built it earlier, including VU3ZOF, VU2EVQ, VU3OPD, VU3AVE, VU3GEX and VU2TDD.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I heard VU3AVE on 40m with good quality audio when he was using a homebrew LMR SDR 1.1 with a homebrew 30W linear amplifier. That made me think of trying to homebrew one and ordered a PCB with Si5351 pre-soldered and three other ICs which are difficult to procure locally. VU3GEX helped me to source [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":16768,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-16761","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>Venturing into homebrewing LMR SDR 1.1 - 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\/venturing-into-homebrewing-lmr-sdr-1-1\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Venturing into homebrewing LMR SDR 1.1 - Johnson&#039;s Techworld\" \/>\n<meta property=\"og:description\" content=\"I heard VU3AVE on 40m with good quality audio when he was using a homebrew LMR SDR 1.1 with a homebrew 30W linear amplifier. That made me think of trying to homebrew one and ordered a PCB with Si5351 pre-soldered and three other ICs which are difficult to procure locally. VU3GEX helped me to source [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/\" \/>\n<meta property=\"og:site_name\" content=\"Johnson&#039;s Techworld\" \/>\n<meta property=\"article:published_time\" content=\"2026-03-30T08:50:49+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-03-31T03:17:52+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2026\/03\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"679\" \/>\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=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/\"},\"author\":{\"name\":\"Johnson Francis\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#\\\/schema\\\/person\\\/6201c843e80ccd3578e6196b1d007027\"},\"headline\":\"Venturing into homebrewing LMR SDR 1.1\",\"datePublished\":\"2026-03-30T08:50:49+00:00\",\"dateModified\":\"2026-03-31T03:17:52+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/\"},\"wordCount\":316,\"publisher\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#\\\/schema\\\/person\\\/6201c843e80ccd3578e6196b1d007027\"},\"image\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg\",\"articleSection\":[\"Amateur Radio (Ham Radio)\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/\",\"name\":\"Venturing into homebrewing LMR SDR 1.1 - Johnson&#039;s Techworld\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg\",\"datePublished\":\"2026-03-30T08:50:49+00:00\",\"dateModified\":\"2026-03-31T03:17:52+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/#primaryimage\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg\",\"contentUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg\",\"width\":1200,\"height\":679},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/venturing-into-homebrewing-lmr-sdr-1-1\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Venturing into homebrewing LMR SDR 1.1\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#website\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/\",\"name\":\"Johnson's Techworld\",\"description\":\"Johnson&#039;s Techworld\",\"publisher\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#\\\/schema\\\/person\\\/6201c843e80ccd3578e6196b1d007027\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":[\"Person\",\"Organization\"],\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/#\\\/schema\\\/person\\\/6201c843e80ccd3578e6196b1d007027\",\"name\":\"Johnson Francis\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/channels4_profile.jpg\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/channels4_profile.jpg\",\"contentUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/channels4_profile.jpg\",\"width\":600,\"height\":600,\"caption\":\"Johnson Francis\"},\"logo\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/techworld\\\/wp-content\\\/uploads\\\/2025\\\/01\\\/channels4_profile.jpg\"},\"description\":\"Amateur Radio Operator VU2JO. 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":"Venturing into homebrewing LMR SDR 1.1 - 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\/venturing-into-homebrewing-lmr-sdr-1-1\/","og_locale":"en_US","og_type":"article","og_title":"Venturing into homebrewing LMR SDR 1.1 - Johnson&#039;s Techworld","og_description":"I heard VU3AVE on 40m with good quality audio when he was using a homebrew LMR SDR 1.1 with a homebrew 30W linear amplifier. That made me think of trying to homebrew one and ordered a PCB with Si5351 pre-soldered and three other ICs which are difficult to procure locally. VU3GEX helped me to source [&hellip;]","og_url":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/","og_site_name":"Johnson&#039;s Techworld","article_published_time":"2026-03-30T08:50:49+00:00","article_modified_time":"2026-03-31T03:17:52+00:00","og_image":[{"width":1200,"height":679,"url":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2026\/03\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg","type":"image\/jpeg"}],"author":"Johnson Francis","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Johnson Francis","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/#article","isPartOf":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/"},"author":{"name":"Johnson Francis","@id":"https:\/\/johnsonfrancis.org\/techworld\/#\/schema\/person\/6201c843e80ccd3578e6196b1d007027"},"headline":"Venturing into homebrewing LMR SDR 1.1","datePublished":"2026-03-30T08:50:49+00:00","dateModified":"2026-03-31T03:17:52+00:00","mainEntityOfPage":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/"},"wordCount":316,"publisher":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/#\/schema\/person\/6201c843e80ccd3578e6196b1d007027"},"image":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/#primaryimage"},"thumbnailUrl":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2026\/03\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg","articleSection":["Amateur Radio (Ham Radio)"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/","url":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/","name":"Venturing into homebrewing LMR SDR 1.1 - Johnson&#039;s Techworld","isPartOf":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/#website"},"primaryImageOfPage":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/#primaryimage"},"image":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/#primaryimage"},"thumbnailUrl":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2026\/03\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg","datePublished":"2026-03-30T08:50:49+00:00","dateModified":"2026-03-31T03:17:52+00:00","breadcrumb":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/#primaryimage","url":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2026\/03\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg","contentUrl":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2026\/03\/Venturing-into-homebrewing-LMR-SDR-1.1.jpg","width":1200,"height":679},{"@type":"BreadcrumbList","@id":"https:\/\/johnsonfrancis.org\/techworld\/venturing-into-homebrewing-lmr-sdr-1-1\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/johnsonfrancis.org\/techworld\/"},{"@type":"ListItem","position":2,"name":"Venturing into homebrewing LMR SDR 1.1"}]},{"@type":"WebSite","@id":"https:\/\/johnsonfrancis.org\/techworld\/#website","url":"https:\/\/johnsonfrancis.org\/techworld\/","name":"Johnson's Techworld","description":"Johnson&#039;s Techworld","publisher":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/#\/schema\/person\/6201c843e80ccd3578e6196b1d007027"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/johnsonfrancis.org\/techworld\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":["Person","Organization"],"@id":"https:\/\/johnsonfrancis.org\/techworld\/#\/schema\/person\/6201c843e80ccd3578e6196b1d007027","name":"Johnson Francis","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2025\/01\/channels4_profile.jpg","url":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2025\/01\/channels4_profile.jpg","contentUrl":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2025\/01\/channels4_profile.jpg","width":600,"height":600,"caption":"Johnson Francis"},"logo":{"@id":"https:\/\/johnsonfrancis.org\/techworld\/wp-content\/uploads\/2025\/01\/channels4_profile.jpg"},"description":"Amateur Radio Operator VU2JO. 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\/"}]}},"_links":{"self":[{"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/posts\/16761","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/comments?post=16761"}],"version-history":[{"count":10,"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/posts\/16761\/revisions"}],"predecessor-version":[{"id":16776,"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/posts\/16761\/revisions\/16776"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/media\/16768"}],"wp:attachment":[{"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/media?parent=16761"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/categories?post=16761"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/johnsonfrancis.org\/techworld\/wp-json\/wp\/v2\/tags?post=16761"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}