{"id":6264,"date":"2013-09-26T10:01:00","date_gmt":"2013-09-26T00:01:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2013\/09\/26\/bitx-build-update-10-darlington\/"},"modified":"2013-09-26T10:01:00","modified_gmt":"2013-09-26T00:01:00","slug":"bitx-build-update-10-darlington","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2013\/09\/26\/bitx-build-update-10-darlington\/","title":{"rendered":"BITX Build Update #10  &#8212; Darling(ton)"},"content":{"rendered":"<p><strong>Having concluded that I was significantly short on overall receiver gain, I went in yesterday and changed my AF amp from a 40db direct-coupled circuit to a 100db Darlington pair. I immediately noticed a big increase in audio output. <\/strong><br \/> <strong><\/strong><br \/> <strong>I did a quick receiver alignment using my Arduino\/AD9860 sig generator. First I determined the actual bandpass of the crystal filter: 4.998170 MHz &#8212; 5.000960 MHz. Using a freq counter, I set the BFO at 5.00126. I immediately started hearing 17 meter SSB signals from the West Coast. That&#8217;s always a nice moment: first signals through a new receiver. Kind of like &#8220;first light&#8221; in a new telescope. Even with the filter ripple, it sounds great. <\/strong><br \/> <strong><\/strong><br \/> <strong>I think I&#8217;m still significantly short of gain. Audio is still faint. I notice that in the BITX17A they have added a second transistor (Q17) in the second RX receive amp. Maybe I should try something similar. Or should I add some gain in the audio chain? <\/strong><br \/> <strong><\/strong><br \/> <strong>I&#8217;m really enjoying this BITX project. <\/strong><br \/> <strong><\/strong><\/p>\n<p> Our book: &#8220;SolderSmoke &#8212; Global Adventures in Wireless Electronics&#8221; <a href=\"http:\/\/soldersmoke.com\/book.htm\">http:\/\/soldersmoke.com\/book.htm<\/a> Our coffee mugs, T-Shirts, bumper stickers: <a href=\"http:\/\/www.cafepress.com\/SolderSmoke\">http:\/\/www.cafepress.com\/SolderSmoke<\/a> Our Book Store: <a href=\"http:\/\/astore.amazon.com\/contracross-20\">http:\/\/astore.amazon.com\/contracross-20<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Having concluded that I was significantly short on overall receiver gain, I went in yesterday and changed my AF amp from a 40db direct-coupled circuit to a 100db Darlington pair. I immediately noticed a big increase in audio output. I did a quick receiver alignment using my Arduino\/AD9860 sig generator. First I determined the actual &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2013\/09\/26\/bitx-build-update-10-darlington\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;BITX Build Update #10  &#8212; Darling(ton)&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28,23],"tags":[],"class_list":["post-6264","post","type-post","status-publish","format-standard","hentry","category-bitx20","category-ssb"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/6264","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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/comments?post=6264"}],"version-history":[{"count":0,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/6264\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=6264"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=6264"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=6264"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}