{"id":6550,"date":"2024-11-02T10:30:00","date_gmt":"2024-11-01T23:30:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2024\/11\/02\/more-background-on-the-mythbuster-ii-rig-and-a-short-video\/"},"modified":"2025-07-22T18:01:20","modified_gmt":"2025-07-22T08:01:20","slug":"more-background-on-the-mythbuster-ii-rig-and-a-short-video","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2024\/11\/02\/more-background-on-the-mythbuster-ii-rig-and-a-short-video\/","title":{"rendered":"More Background on the Mythbuster II Rig (and a short video)"},"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\/ff_rBSI35yk?si=T_8AQD2cPVS8ngYF?rel=0\" title=\"YouTube video player\" width=\"440\"><\/iframe> <\/p>\n<p><span face=\"\"Trebuchet MS\", Verdana, Arial, sans-serif\" style=\"background-color: white; color: #333333; text-align: justify;\"><b>Above is a short clip of me hearing an old friend on the new receiver. TRGHS. <\/b><\/span><\/p>\n<p><b>A couple of guys on Facebook asked for a schematic for this rig. I don&#8217;t really have one &#8212; as you will see it is a collection of different circuits from lots of different sources. I was also thinking that if you need a schematic for a rig like this, you probably shouldn&#8217;t try to build a rig like this. But in an effort to be nice, I supply here some background info on some of the circuitry and parts sources. And no, I don&#8217;t have BOMs nor Gerber files. <\/b><\/p>\n<p><span style=\"background-color: white; color: #333333; text-align: justify;\"><b>More info on the Yaesu VFO is here:<\/b><\/span><\/p>\n<p><span face=\"\"Trebuchet MS\", Verdana, Arial, sans-serif\" style=\"background-color: white; color: #333333; text-align: justify;\"><a href=\"https:\/\/soldersmoke.blogspot.com\/2021\/07\/mythbuster-video-3-using-vfo-from-yaesu.html\"><b>https:\/\/soldersmoke.blogspot.com\/2021\/07\/mythbuster-video-3-using-vfo-from-yaesu.html<\/b><\/a><\/span><\/p>\n<div><b><br \/><\/b><\/div>\n<div><b><span face=\"\"Trebuchet MS\", Verdana, Arial, sans-serif\" style=\"background-color: white; color: #333333; text-align: justify;\">The VFO is kind of high in frequency. But it is very stable. I can&#8217;t really take credit for this &#8212; the credit goes to Yaesu. But I like the circuit because it is all analog and all discrete component. It even has a split stator temperature compensation variable cap! At Pete&#8217;s recommendation, I originally bought these boxes thinking that I&#8217;d just get the anti-backlash gears and the reduction drives. But the sellers always sent the entire VFO boxes. They even come with a &#8220;clarifier&#8221; circuit which I now use as an &#8220;up 5-10&#8221; feature that lets me work the DX-peditions on 20.<\/span><br style=\"background-color: white; color: #333333; font-family: \"Trebuchet MS\", Verdana, Arial, sans-serif; text-align: justify;\" \/><br style=\"background-color: white; color: #333333; font-family: \"Trebuchet MS\", Verdana, Arial, sans-serif; text-align: justify;\" \/><span face=\"\"Trebuchet MS\", Verdana, Arial, sans-serif\" style=\"background-color: white; color: #333333; text-align: justify;\">As for the tape, I got mine from Amazon. It has conductive adhesive:<\/span><br style=\"background-color: white; color: #333333; font-family: \"Trebuchet MS\", Verdana, Arial, sans-serif; text-align: justify;\" \/><span face=\"\"Trebuchet MS\", Verdana, Arial, sans-serif\" style=\"background-color: white; color: #333333; text-align: justify;\"><a href=\"https:\/\/www.amazon.com\/gp\/product\/B07QQJ4MX1\/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&#038;psc=1\">https:\/\/www.amazon.com\/gp\/product\/B07QQJ4MX1\/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&#038;psc=1<\/a><\/span><\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>The boards for the IF Termination Insensitive Amplifiers come from Todd K7 TFC at Mostly DIY RF: <a href=\"https:\/\/mostlydiyrf.com\/tia\/\">https:\/\/mostlydiyrf.com\/tia\/<\/a><\/b><\/div>\n<div><\/div>\n<div><b>The little LM386 boards that I have been using are available here: <a href=\"https:\/\/www.amazon.com\/dp\/B00LNACGTY?ref=ppx_yo2ov_dt_b_fed_asin_title\">https:\/\/www.amazon.com\/dp\/B00LNACGTY?ref=ppx_yo2ov_dt_b_fed_asin_title<\/a> I precede it with one stage of AF amplification from the original BITX 20 sechematic. I put a 10K pot between this stage and the LM386 board. <\/b><\/div>\n<div><b><br \/><\/b><\/div>\n<div><b>Here is the Amazon source for the 1\/8 inch plywood that I will use for the case (I have used up all the pandemic treadmill packing material): <\/b><\/div>\n<div><b><a href=\"https:\/\/www.amazon.com\/dp\/B0D5VCBBP4?ref=ppx_yo2ov_dt_b_fed_asin_title&#038;th=1\">https:\/\/www.amazon.com\/dp\/B0D5VCBBP4?ref=ppx_yo2ov_dt_b_fed_asin_title&#038;th=1<\/a><\/b><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Above is a short clip of me hearing an old friend on the new receiver. TRGHS. A couple of guys on Facebook asked for a schematic for this rig. I don&#8217;t really have one &#8212; as you will see it is a collection of different circuits from lots of different sources. I was also thinking &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2024\/11\/02\/more-background-on-the-mythbuster-ii-rig-and-a-short-video\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;More Background on the Mythbuster II Rig (and a short video)&#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":[115,215,232,132,38,53],"tags":[],"class_list":["post-6550","post","type-post","status-publish","format-standard","hentry","category-audio-amplifiers","category-carney-todd","category-ireland","category-mythbuster","category-parts-suppliers","category-vfo"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/6550","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=6550"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/6550\/revisions"}],"predecessor-version":[{"id":11187,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/6550\/revisions\/11187"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=6550"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=6550"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=6550"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}