{"id":7819,"date":"2021-08-07T09:35:00","date_gmt":"2021-08-06T23:35:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2021\/08\/07\/mythbuster-video-13-rf-power-amplifier-and-relay-switching-plan\/"},"modified":"2025-07-22T18:04:37","modified_gmt":"2025-07-22T08:04:37","slug":"mythbuster-video-13-rf-power-amplifier-and-relay-switching-plan","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2021\/08\/07\/mythbuster-video-13-rf-power-amplifier-and-relay-switching-plan\/","title":{"rendered":"Mythbuster Video #13 &#8212; RF Power Amplifier, and Relay Switching Plan"},"content":{"rendered":"<p><iframe loading=\"lazy\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen=\"\" frameborder=\"0\" height=\"247\" src=\"https:\/\/www.youtube.com\/embed\/H2gbCRKljJc?rel=0\" title=\"YouTube video player\" width=\"440\"><\/iframe><\/p>\n<div><\/div>\n<div><span face=\"Roboto, Arial, sans-serif\" style=\"background-color: #f9f9f9; color: #030303; font-size: 14px; letter-spacing: 0.2px; white-space: pre-wrap;\"><b>In this episode we enter into the most fraught part of the construction project: the production of RF power. This is where amplifiers stubbornly turn into oscillators, and where components release magic smoke, or at least burn the fingers of hopeful builders.<\/b><\/span><\/div>\n<div><span face=\"Roboto, Arial, sans-serif\" style=\"color: #030303;\"><span style=\"font-size: 14px; letter-spacing: 0.2px; white-space: pre-wrap;\"><b><br \/><\/b><\/span><\/span><\/div>\n<div><span face=\"Roboto, Arial, sans-serif\" style=\"color: #030303;\"><span style=\"font-size: 14px; letter-spacing: 0.2px; white-space: pre-wrap;\"><b>I kind of ran out of room when I built the low-pass filters. But, thinking ahead, I wanted to have them on a separate board. And it is good that they ended up in the far corner of the rig. <\/b><\/span><\/span><\/div>\n<div><span face=\"Roboto, Arial, sans-serif\" style=\"color: #030303;\"><span style=\"font-size: 14px; letter-spacing: 0.2px; white-space: pre-wrap;\"><b><br \/><\/b><\/span><\/span><\/div>\n<div><span face=\"Roboto, Arial, sans-serif\" style=\"color: #030303;\"><span style=\"font-size: 14px; letter-spacing: 0.2px; white-space: pre-wrap;\"><b>Just going from one band to two bands adds to the complexity of the rig. I had to add two relays, one to switch the low pass filters, the other to switch the bandpass filters. I ended up with 5 DPDT relays in this transceiver. It was very helpful to have a plan and a diagram for the relays and all the switching. <\/b><\/span><\/span><\/div>\n<div><span face=\"Roboto, Arial, sans-serif\" style=\"color: #030303;\"><span style=\"font-size: 14px; letter-spacing: 0.2px; white-space: pre-wrap;\"><b><br \/><\/b><\/span><\/span><\/div>\n<div><span face=\"Roboto, Arial, sans-serif\" style=\"color: #030303;\"><span style=\"font-size: 14px; letter-spacing: 0.2px; white-space: pre-wrap;\"><b>It looks like each of the three RF amplifier stages provides about 15 db of gain &#8212; about what I need to get to the 5 watt level. <\/b><\/span><\/span><\/div>\n","protected":false},"excerpt":{"rendered":"<p>In this episode we enter into the most fraught part of the construction project: the production of RF power. This is where amplifiers stubbornly turn into oscillators, and where components release magic smoke, or at least burn the fingers of hopeful builders. I kind of ran out of room when I built the low-pass filters. &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2021\/08\/07\/mythbuster-video-13-rf-power-amplifier-and-relay-switching-plan\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Mythbuster Video #13 &#8212; RF Power Amplifier, and Relay Switching Plan&#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":[20,339,16,132,23],"tags":[],"class_list":["post-7819","post","type-post","status-publish","format-standard","hentry","category-20-meters","category-75-meters","category-filters","category-mythbuster","category-ssb"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7819","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=7819"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7819\/revisions"}],"predecessor-version":[{"id":11447,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/7819\/revisions\/11447"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=7819"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=7819"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=7819"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}