{"id":8870,"date":"2019-07-29T20:48:00","date_gmt":"2019-07-29T10:48:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2019\/07\/29\/walter-ka4kxx-operates-his-fb-al-fresco-hb-scratch-built-bitx-75-video\/"},"modified":"2019-07-29T20:48:00","modified_gmt":"2019-07-29T10:48:00","slug":"walter-ka4kxx-operates-his-fb-al-fresco-hb-scratch-built-bitx-75-video","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2019\/07\/29\/walter-ka4kxx-operates-his-fb-al-fresco-hb-scratch-built-bitx-75-video\/","title":{"rendered":"Walter KA4KXX Operates his FB Al-Fresco HB Scratch-Built BITX 75 (Video)"},"content":{"rendered":"<p><iframe loading=\"lazy\" allow=\"accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen=\"\" frameborder=\"0\" height=\"247\" src=\"https:\/\/www.youtube.com\/embed\/r0SC664W4GY?start=145\" width=\"440\"><\/iframe><\/p>\n<p> <span style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"><b>Dear Bill N2CQR:<\/b><\/span><br \/> <span style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"><b><br \/><\/b><\/span> <\/p>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b>For your amusement, the attached video (from 2:20 &#8211; 3:40) shows<\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b>me operating portable at a tailgate event using my second<\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b>scratch-built <span style=\"line-height: 1.5;\"> BITX, with this one running 45W on 75M. <\/span><\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>Features include analog VFO, a 16-pin LM380 with all ground<\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b><span style=\"line-height: 1.5;\">pins heat-sinked for powerful audio, and 3-transistor <\/span><span style=\"line-height: 1.5;\">uBITX-type<\/span><\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>low-level RF amps. The 8-crystal filter is also like the uBITX design<\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>but at an 11 MHz IF. The microphone amp is a 741 Op Amp which I<\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>believe has better gain, gain adjustability, and frequency response than <\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b><span style=\"line-height: 1.5;\">any of the transistor designs. <\/span><span style=\"line-height: 1.5;\">The transmit adjustable driver amp is adapted from the FET <\/span><\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b><span style=\"line-height: 1.5;\">circuit used in the Wee Willy. <\/span><span style=\"line-height: 1.5;\">The Transmit LPF is hard-wired to the antenna <\/span><span style=\"line-height: 1.5;\">connector <\/span><\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b><span style=\"line-height: 1.5;\">for simplification and to minimize RF losses, so <\/span><span style=\"line-height: 1.5;\">in receive mode the single relay in the rig <\/span><\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b><span style=\"line-height: 1.5;\">connects the <\/span><span style=\"line-height: 1.5;\">receive <\/span><span style=\"line-height: 1.5;\">section in parallel, <\/span><span style=\"line-height: 1.5;\">which causes some signal <\/span><span style=\"line-height: 1.5;\">loss, but not much. <\/span><\/b><\/div>\n<div style=\"color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b><span style=\"line-height: 1.5;\"><span style=\"background-color: white;\">Finally, and most notably,<\/span><span style=\"background-color: yellow;\"> I believe that my <\/span><\/span><span style=\"background-color: yellow;\"><span style=\"line-height: 1.5;\">RF Power Amp is the <\/span><span style=\"line-height: 1.5;\">only <\/span><span style=\"line-height: 1.5;\">one in the world to use <\/span><\/span><\/b><\/div>\n<div style=\"color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <b style=\"background-color: yellow;\"><span style=\"line-height: 1.5;\">model <\/span><span style=\"line-height: 1.5;\">airplane <\/span><span style=\"line-height: 1.5;\">engine mufflers <\/span><span style=\"line-height: 1.5;\">as heat sink cores&#8230;<\/span><\/b><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b><br \/><\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>72,<\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>Walter<\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>KA4KXX<\/b><\/span><\/div>\n<div style=\"background-color: white; color: #1d2228; font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif; font-size: 13px;\"> <span style=\"line-height: 1.5;\"><b>Orlando, FL <\/b><\/span><\/div>\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Dear Bill N2CQR: For your amusement, the attached video (from 2:20 &#8211; 3:40) shows me operating portable at a tailgate event using my second scratch-built BITX, with this one running 45W on 75M. Features include analog VFO, a 16-pin LM380 with all ground pins heat-sinked for powerful audio, and 3-transistor uBITX-type low-level RF amps. The &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2019\/07\/29\/walter-ka4kxx-operates-his-fb-al-fresco-hb-scratch-built-bitx-75-video\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Walter KA4KXX Operates his FB Al-Fresco HB Scratch-Built BITX 75 (Video)&#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":[339,28],"tags":[],"class_list":["post-8870","post","type-post","status-publish","format-standard","hentry","category-75-meters","category-bitx20"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/8870","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=8870"}],"version-history":[{"count":0,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/8870\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=8870"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=8870"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=8870"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}