{"id":10883,"date":"2023-02-21T11:55:00","date_gmt":"2023-02-21T00:55:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2023\/02\/21\/farhans-direct-conversion-receiver\/"},"modified":"2025-07-22T18:02:26","modified_gmt":"2025-07-22T08:02:26","slug":"farhans-direct-conversion-receiver","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2023\/02\/21\/farhans-direct-conversion-receiver\/","title":{"rendered":"Farhan&#8217;s Direct Conversion Receiver"},"content":{"rendered":"<\/p>\n<div class=\"separator\" style=\"clear: both; text-align: center;\"><a href=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2023\/02\/IMG-5265.jpg\" style=\"margin-left: 1em; margin-right: 1em;\"><img loading=\"lazy\" decoding=\"async\" border=\"0\" data-original-height=\"3024\" data-original-width=\"4032\" height=\"264\" src=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2023\/02\/IMG-5265.jpg\" width=\"352\" \/><\/a><\/div>\n<\/p>\n<p><b>Thank God for the Wayback machine. For a moment I feared that this article about Farhan&#8217;s DC-40 receiver had been lost. (Phonestack is now some Vietnamese vendor. ) But the WayBack Machine archive came through for us. <\/b><\/p>\n<p><a href=\"https:\/\/web.archive.org\/web\/20171109081542\/http:\/\/www.phonestack.com\/farhan\/dc40.html\"><b>https:\/\/web.archive.org\/web\/20171109081542\/http:\/\/www.phonestack.com\/farhan\/dc40.html<\/b><\/a><\/p>\n<p><b>Farhan&#8217;s receiver has been<a href=\"https:\/\/soldersmoke.blogspot.com\/2020\/08\/presence-absence-and-direct-conversion.html\"> covered on this blog before,<\/a> but it is especially relevant for us now that we are immersed in <a href=\"https:\/\/soldersmoke.blogspot.com\/search\/label\/TJ%20DC%20RX\">our own direct conversion receiver project<\/a>. Farhan was working with his niece, who was a student. We are working with high school students. <\/b><\/p>\n<p><b>I really like Farhan&#8217;s blow-by-blow description of the build. There are raw emotions here: He speaks of his hatred of LM-386s, and of how he thought of using the copper clad board as a projectile. His niece wonders about the possibility of evil spirits in the receiver. The battle against AM breakthrough is very familiar. (I like the RF choke idea.) You won&#8217;t find candor like this in QST or QEX. <\/b><\/p>\n<p><b>Farhan&#8217;s DC-40 project was one of the inspirations for our high school effort. In fact, when we first went to the school, I left behind a direct conversion receiver that I had built. Taped onto the bottom of the receiver was a quote from the DC-40 article and a picture of the Wizard of Hyderabad. (See above, and click on the picture for a better look). <\/b><\/p>\n<p><b>This week we will inject some more Farhan-ismo into our receiver. The time has come to build the mixer. Like Farhan, we will go with the diode ring. Winding the transformers would be very time consuming. I remembered that on his visit, Farhan had left me a box of trifilar toroids wound by the seamstresses of Hyderabad using FT37-43 cores. We will uses these in our build. They will add a lot of soul to the new machine. <\/b><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Thank God for the Wayback machine. For a moment I feared that this article about Farhan&#8217;s DC-40 receiver had been lost. (Phonestack is now some Vietnamese vendor. ) But the WayBack Machine archive came through for us. https:\/\/web.archive.org\/web\/20171109081542\/http:\/\/www.phonestack.com\/farhan\/dc40.html Farhan&#8217;s receiver has been covered on this blog before, but it is especially relevant for us now &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2023\/02\/21\/farhans-direct-conversion-receiver\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Farhan&#8217;s Direct Conversion Receiver&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":10884,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35,66,68,12],"tags":[],"class_list":["post-10883","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-direct-conversion","category-farhan","category-india","category-tj-dc-rx"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10883","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=10883"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10883\/revisions"}],"predecessor-version":[{"id":10885,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10883\/revisions\/10885"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/10884"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=10883"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=10883"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=10883"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}