{"id":2473,"date":"2021-11-02T15:14:00","date_gmt":"2021-11-02T04:14:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2021\/11\/02\/farhans-amazing-knack-story-from-a-boyhood-sw-receiver-to-the-design-of-the-sbitx-sdr\/"},"modified":"2025-07-22T18:04:30","modified_gmt":"2025-07-22T08:04:30","slug":"farhans-amazing-knack-story-from-a-boyhood-sw-receiver-to-the-design-of-the-sbitx-sdr","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2021\/11\/02\/farhans-amazing-knack-story-from-a-boyhood-sw-receiver-to-the-design-of-the-sbitx-sdr\/","title":{"rendered":"Farhan&#8217;s Amazing Knack Story:  From a Boyhood SW Receiver to the Design of the sBITX SDR"},"content":{"rendered":"<p><iframe loading=\"lazy\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen=\"\" frameborder=\"0\" height=\"247\" src=\"https:\/\/www.youtube.com\/embed\/OARYpMjAbgI?start=240?rel=0\" title=\"YouTube video player\" width=\"440\"><\/iframe><\/p>\n<div><\/div>\n<div><b>The presentation starts at about the 4 minute point. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>I think if I were only allowed to watch one YouTube video in the next year, I&#8217;d make it this one. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>In this amazing RSGB video, Ashhar Farhan VU2ESE takes us back to his earliest days as a radio amateur. He tells us about his very early desire to build radios, his early projects, and his personal evolution as a designer and builder, from a simple DC receiver, to the BITX, the Minima, the uBITX and now the hybrid HDR\/SDR sBITX. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>There is a lot of homebrew wisdom and tribal knowledge in this video. And we learn so many hitherto unknown details about the rigs that have become so important to us: <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; Farhan had the EMRFD book with him on the famous flight from Sweden to India during which the BITX was designed. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; We learn about the origins of the BITX oscillator circuits, and that the VFO and BFO are essentially the same. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; I was really pleased that Farhan included a picture of my HB BITX17 rig in his presentation. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; Farhan discusses the difficulties he faced in obtaining needed parts in India. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; We actually see the nylon washers that Farhan used in the original BITX. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; Farhan discusses his early system for measuring coil inductance. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; In addition the huge contribution of EMRFD, Farhan talks about how he was helped by Pat Hawker G3VA&#8217;s writing, and the ARRL&#8217;s SSB Handbook. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; Farhkan talks about his Tex 465 &#8216;scope and his building of a Spectrum Analyzer. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>&#8212; We see his evolution to dual conversion. We see the conceptual birth of the Minima and the birth (thanks Wes!) of the TIA amps. I didn&#8217;t know about the HF-1. Then Farhan designed the uBITX and now the sBITX. <br \/><\/b><\/p>\n<p><b> &#8212; Farhan talks about his practice of taking the pictures of new rigs with the new rig sitting atop the book that was most important in its design and construction. FB. <\/b><\/p>\n<p><b>&#8212; I was really blown away by Farhan&#8217;s presentation of how the uBITX advertisement was inspired by and in many ways based on the Heathkit ad for an HW-101. Amazing. <\/b><\/p>\n<p><b>&#8212; I learned a lot from Farhan&#8217;s discussion of SDR theory. I pledge to spend more time with this. I really like Farhan&#8217;s hybrid HDR\/SDR approach. <\/b><\/p>\n<p><b>&#8212; But I have a question: Farhan seems to say that we&#8217;d need a big expensive GOOGL computer to do the direct sampling HF SDR. But doesn&#8217;t the little RTL-SDR do just that? Without a GOOGL? <\/b><\/p>\n<p><b>&#8212; Great to see Wes&#8217;s AFTIA being used in the sBITX. <\/b><\/p>\n<p><b>&#8212; Really cool that Farhan has his mind on VHF transverters when designing the sBITX. I liked use of the TCXO module to free up one of the Si5351 clock outputs. FB. And great to include an idea from Hans in this rig. <\/b><\/p>\n<p><b>Thanks very much to Farhan (who stayed up until 3 am to do this!) and to the RSGB for hosting.<\/b><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The presentation starts at about the 4 minute point. I think if I were only allowed to watch one YouTube video in the next year, I&#8217;d make it this one. In this amazing RSGB video, Ashhar Farhan VU2ESE takes us back to his earliest days as a radio amateur. He tells us about his very &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2021\/11\/02\/farhans-amazing-knack-story-from-a-boyhood-sw-receiver-to-the-design-of-the-sbitx-sdr\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Farhan&#8217;s Amazing Knack Story:  From a Boyhood SW Receiver to the Design of the sBITX SDR&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28,94,66,60,160,68,103,343,40,198,117,119,129],"tags":[],"class_list":["post-2473","post","type-post","status-publish","format-standard","hentry","category-bitx20","category-emrfd","category-farhan","category-hayward-wes","category-hw-101","category-india","category-knack-stories","category-minima","category-sdr","category-summers-hans","category-ubitx","category-uk","category-vhf"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2473","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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/comments?post=2473"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2473\/revisions"}],"predecessor-version":[{"id":11430,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2473\/revisions\/11430"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=2473"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=2473"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=2473"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}