{"id":10779,"date":"2013-10-16T23:38:00","date_gmt":"2013-10-16T12:38:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2013\/10\/16\/yikes-screeching-transistors-throwing-off-blue-light\/"},"modified":"2013-10-16T23:38:00","modified_gmt":"2013-10-16T12:38:00","slug":"yikes-screeching-transistors-throwing-off-blue-light","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2013\/10\/16\/yikes-screeching-transistors-throwing-off-blue-light\/","title":{"rendered":"Yikes! Screeching Transistors Throwing off Blue Light!"},"content":{"rendered":"<div style=\"text-align: center;\"> <strong><a data-ved=\"0CAUQjRw\" href=\"http:\/\/www.google.com\/url?sa=i&#038;rct=j&#038;q=&#038;esrc=s&#038;frm=1&#038;source=images&#038;cd=&#038;cad=rja&#038;docid=TfTLIAJh_aR4EM&#038;tbnid=uhhtfPc9wiXjfM:&#038;ved=0CAUQjRw&#038;url=http%3A%2F%2Fwww.ae5x.com%2Fblog%2F2012%2F05%2F16%2Ftoroids-broadband-transformer-bulletins-de-w1fb%2F&#038;ei=viJfUsKjFYvw8ASliYD4Aw&#038;bvm=bv.54176721,d.eWU&#038;psig=AFQjCNEhKrcxdzz-VVumucPqR_gnAX5N5w&#038;ust=1382052883421578\" id=\"irc_mil\" style=\"border: 0px currentColor;\"><img loading=\"lazy\" decoding=\"async\" height=\"293\" id=\"irc_mi\" src=\"http:\/\/www.ae5x.com\/blog\/wp-content\/uploads\/2012\/05\/w1fb.jpg\" style=\"margin-top: 68px;\" width=\"246\" \/><\/a><\/strong><\/div>\n<p> <strong><\/strong><br \/> <strong><\/strong><br \/> <strong>I found a quote from Doug DeMaw that I wanted to share. This one seems appropriate as I struggle with unwanted oscillation (and as Halloween approaches). From the January 1986 QST: <\/strong><br \/> <strong><\/strong><br \/> <strong>&#8220;Self -oscillation occurs not only in the low-frequency and high-frequency spectrum, but it often takes place at audio frequencies! I have actually heard the transistors &#8220;screeching&#8221; when strong audio oscillations were taking place in a homebrew transistor power amplifier. On one occasion I could see <span style=\"color: blue;\">a bluish glow<\/span> coming from within the transistors (visible through the ceramic heads of the devices) during a period of instability. Needless to say, the transistors self-destructed.&#8221; <\/strong><br \/> <strong><\/strong><br \/> <strong>I&#8217;ve been having some instability problems with my BITX 17 IRF510 final. But I think I have the problem identified. I was getting low frequency oscillations (around 100 KHz). Tonight tried putting the IRF510 on a separate power supply. The oscillations ceased and I am getting a nice clean 3 watts out. So I&#8217;ll go back and beef up the decoupling on the power supply lines.<\/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>I found a quote from Doug DeMaw that I wanted to share. This one seems appropriate as I struggle with unwanted oscillation (and as Halloween approaches). From the January 1986 QST: &#8220;Self -oscillation occurs not only in the low-frequency and high-frequency spectrum, but it often takes place at audio frequencies! I have actually heard the &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2013\/10\/16\/yikes-screeching-transistors-throwing-off-blue-light\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Yikes! Screeching Transistors Throwing off Blue Light!&#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":[28,7,25],"tags":[],"class_list":["post-10779","post","type-post","status-publish","format-standard","hentry","category-bitx20","category-demaw-doug","category-troubleshooting"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10779","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=10779"}],"version-history":[{"count":0,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10779\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=10779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=10779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=10779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}