{"id":7861,"date":"2025-03-27T20:18:00","date_gmt":"2025-03-27T09:18:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2025\/03\/27\/dave-g6gevs-very-fb-soldersmoke-direct-conversion-receiver-with-an-innovative-bic-pen-pto\/"},"modified":"2025-07-22T18:00:58","modified_gmt":"2025-07-22T08:00:58","slug":"dave-g6gevs-very-fb-soldersmoke-direct-conversion-receiver-with-an-innovative-bic-pen-pto","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2025\/03\/27\/dave-g6gevs-very-fb-soldersmoke-direct-conversion-receiver-with-an-innovative-bic-pen-pto\/","title":{"rendered":"Dave G6GEV&#8217;s Very FB SolderSmoke Direct Conversion Receiver, with an Innovative Bic Pen PTO!"},"content":{"rendered":"<p><iframe loading=\"lazy\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen=\"\" frameborder=\"0\" height=\"247\" referrerpolicy=\"strict-origin-when-cross-origin\" src=\"https:\/\/www.youtube.com\/embed\/4NiE3ikkAw0?si=ZESZ_jcXi3xRJxJ9?rel=0\" title=\"YouTube video player\" width=\"440\"><\/iframe><\/p>\n<div><\/div>\n<div><b>This is a really nice one. In the &#8220;proof of life&#8221; video we find a lot of proof, and a lot of life. SSB from the UK sounds really good. This is one of the beauties of the Direct Conversion architecture &#8212; you end up with a receiver that sounds very good. Doug DeMaw said these receivers have &#8220;presence&#8221; &#8212; it sounds like the other fellow is present in the room with you. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Dave&#8217;s happiness and satisfaction really shines through in his comments. <\/b><b>Dave writes: <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div>\n<div><i><b>I&#8217;ve just completed my DCR, and it&#8217;s been an absolute blast!<\/b><\/i><\/div>\n<div><i><b><br \/><\/b><\/i><\/div>\n<div><i><b>I&#8217;m a retired EE, where PCBs and surface-mount components are the norm. I&#8217;ve occasionally prototyped using dead bug or Vero-board, but this is my first exposure to Manhattan construction &#8211; and I&#8217;ve thoroughly enjoyed it. Electronics and radio were my childhood passions, but inevitably, they lost some of their appeal once they became a career. Thank you, Bill and Dean, for helping me regain some of that lost joy!<\/b><\/i><\/div>\n<div><i><b><br \/><\/b><\/i><\/div>\n<div><i><b>My biggest challenge was trying to locate parts from a single UK source to minimize shipping costs (yes, I&#8217;m cheap). I briefly contemplated building a push-pull audio amp to avoid purchasing the transformer from Mouser, but in the end, I found most parts there, then padded the order with common junkbox parts to get free shipping. I&#8217;m so pleased that I heeded Bill and Dean&#8217;s advice to build the receiver as presented (well, almost). The results are so much better than I expected, with great-sounding, room-filling audio when connected to the passive half of an old active stereo speaker pair. Tuning is a bit fiddly but improves with practice. Luckily, I had no problems with any of the stages, and it just worked when the boards finally came together. <\/b><\/i><\/div>\n<div><i><b><br \/><\/b><\/i><\/div>\n<div><i><b>To save money (did I mention that I&#8217;m cheap?), I decided to use NP0 capacitors in the PTO instead of silver mica. The thermal coefficient should be similar, and if they didn&#8217;t work out, I planned to swap to mica later on. It turns out NP0 works great for me, with no noticeable drift after several minutes.<\/b><\/i><\/div>\n<\/div>\n<div><i><b><br \/><\/b><\/i><\/div>\n<div><b><\/p>\n<div style=\"font-style: italic;\">I don&#8217;t have easy access to a 3D printer, so I decided to roll my own PTO former. I wound the coil on a Bic Biro with a layer of heat-shrink tubing to bring the diameter to 10mm. This was glued to a wooden support, and the M6 threaded brass bar was a perfect fit inside the Biro. I finished it off with a tuning knob made from an old RC aircraft prop spinner. After experimenting with coil spacing, I ended up with wide spacing under the actively tuned area of the coil and tight spacing at the other end. This reduced the tuning sensitivity, and I now get around 40 kHz per revolution.<\/div>\n<div style=\"font-style: italic;\"><\/div>\n<div style=\"font-style: italic;\">I&#8217;d really like to make a home-brew 2-way contact with this receiver, so maybe I&#8217;ll try a DSB transmitter next&#8230;<\/div>\n<div style=\"font-style: italic;\"><\/div>\n<div style=\"font-style: italic;\">Thanks again to Bill and Dean for providing this fantastic resource. I&#8217;ve been a SolderSmoke listener since episode #1, and after 20 years of constructing radios vicariously, I&#8217;ve finally built one myself!<\/div>\n<div style=\"font-style: italic;\">&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<\/div>\n<div style=\"font-style: italic;\"><\/div>\n<div style=\"font-style: italic;\">FB Dave! Thanks and congratulations.<\/div>\n<div style=\"font-style: italic;\"><\/div>\n<div style=\"font-style: italic;\">&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-<\/div>\n<p><\/b><\/p>\n<p style=\"background-color: white; color: #333333; font-family: \"Trebuchet MS\", Verdana, Arial, sans-serif; font-size: 12.61px; margin: 0px 0px 0.75em;\"><b style=\"color: #222222; font-family: Arial, Helvetica, sans-serif; font-size: small;\">For more information on how you too can build the receiver: <\/b><\/p>\n<div style=\"background-color: white; color: #333333; font-family: \"Trebuchet MS\", Verdana, Arial, sans-serif; font-size: 12.61px;\">\n<div class=\"separator\" style=\"clear: both; color: #222222; font-family: Arial, Helvetica, sans-serif; font-size: small;\"><b><br \/><\/b><\/div>\n<div class=\"separator\" style=\"clear: both; color: #222222; font-family: Arial, Helvetica, sans-serif; font-size: small;\">\n<p class=\"MsoNormal\" style=\"background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin: 0px;\"><b><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\">Join the discussion &#8211; SolderSmoke Discord Server:<\/span><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><u><\/u><u><\/u><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin: 0px;\"><b><span face=\"Arial, sans-serif\" style=\"color: #1155cc; font-size: 12pt;\"><a data-saferedirecturl=\"https:\/\/www.google.com\/url?q=https:\/\/discord.gg\/Fu6B7yGxx2&#038;source=gmail&#038;ust=1739470652838000&#038;usg=AOvVaw1ZoxkyzfQb8pwED_KtyCKW\" href=\"https:\/\/discord.gg\/Fu6B7yGxx2\" style=\"color: #1155cc; cursor: pointer; text-decoration-line: none;\" target=\"_blank\"><span style=\"color: #0066cc;\">https:\/\/discord.gg\/Fu6B7yGxx2<\/span><\/a><\/span><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><u><\/u><u><\/u><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin: 0px;\"><b><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"> <\/span><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><u><\/u><u><\/u><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin: 0px;\"><b><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\">Documentation on Hackaday:<\/span><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><u><\/u><u><\/u><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin: 0px;\"><b><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><a data-saferedirecturl=\"https:\/\/www.google.com\/url?q=https:\/\/hackaday.io\/project\/190327-high-schoolers-build-a-radio-receiver&#038;source=gmail&#038;ust=1739470652838000&#038;usg=AOvVaw026vJuHIWdv6aJ9NJ9QDHJ\" href=\"https:\/\/hackaday.io\/project\/190327-high-schoolers-build-a-radio-receiver\" style=\"color: #1155cc; cursor: pointer; text-decoration-line: none;\" target=\"_blank\">https:\/\/hackaday.io\/project\/<wbr><\/wbr>190327-high-schoolers-build-a-<wbr><\/wbr>radio-receiver<\/a><\/span><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><u><\/u><u><\/u><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin: 0px;\"><b><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"> <\/span><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><u><\/u><u><\/u><\/span><\/b><\/p>\n<p class=\"MsoNormal\" style=\"background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin: 0px;\"><b><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\">SolderSmoke YouTube channel:<\/span><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><u><\/u><u><\/u><\/span><\/b><\/p>\n<\/div>\n<\/div>\n<p><b><\/p>\n<div style=\"font-style: italic;\"><b style=\"background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-size: small;\"><span face=\"Arial, sans-serif\" style=\"font-size: 12pt;\"><a data-saferedirecturl=\"https:\/\/www.google.com\/url?q=https:\/\/www.youtube.com\/@soldersmoke&#038;source=gmail&#038;ust=1739470652838000&#038;usg=AOvVaw3FnV3eIUU7IiaVG8c_Qd3v\" href=\"https:\/\/www.youtube.com\/@soldersmoke\" style=\"color: #1155cc; cursor: pointer; text-decoration-line: none;\" target=\"_blank\">https:\/\/www.youtube.com\/@<wbr><\/wbr>soldersmoke<\/a><\/span><\/b> <\/div>\n<p><\/b><\/div>\n","protected":false},"excerpt":{"rendered":"<p>This is a really nice one. In the &#8220;proof of life&#8221; video we find a lot of proof, and a lot of life. SSB from the UK sounds really good. This is one of the beauties of the Direct Conversion architecture &#8212; you end up with a receiver that sounds very good. Doug DeMaw said &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2025\/03\/27\/dave-g6gevs-very-fb-soldersmoke-direct-conversion-receiver-with-an-innovative-bic-pen-pto\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Dave G6GEV&#8217;s Very FB SolderSmoke Direct Conversion Receiver, with an Innovative Bic Pen PTO!&#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":[9,11,12,119],"tags":[],"class_list":["post-7861","post","type-post","status-publish","format-standard","hentry","category-dc-receiver-build","category-dc-rx-hall-of-fame","category-tj-dc-rx","category-uk"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7861","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=7861"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7861\/revisions"}],"predecessor-version":[{"id":11111,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7861\/revisions\/11111"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=7861"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=7861"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=7861"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}