The tests yesterday went well enough that I was comfortable getting on the air. So far the GaN FET is holding strong! I think the tweaks to the circuits improved efficiency (around 90% PAE I think) and removed the risk of a 200 amp current surge as it turned off. The Class F portion of the amp is super sensitive to SWR, and it’s windy, so I’m watching my antenna carefully. The Class H envelope-tracking-power-supply-modulating portion appears to have enough bandwidth that my audio is good. That’s a bit of a relief.<\/p>\n\n\n\n
Also, the 60V 20A supply I’m using to power the amplifier is super noisy. I have to turn it off to hear anything. But my amp is designed to be a bypass when powered down. <\/p>\n\n\n\n
I ordered a lithium polymer battery to run my amp. That should help cut down on the noise. A lot.<\/p>\n\n\n\n
Made my first contact, cutting through a pileup on 14.262 (Travis was live streaming) <\/p>\n\n\n\n
Update 1: 20 over 9 into the Bay area from Washington State! I’ll take it!<\/p>\n\n\n\n
Update 2: Made a good handful of contacts. Audio report was generally good, clean audio. Then I cranked it up another 5% and the FET popped. So back into the garage it goes. I have one FET left. I should probably get some spares. And maybe start a design that will actually get me 1000 watts.<\/p>\n\n\n\n
Update 3: Replaced the FET. Sticking to 20 watts in (maybe 400+ watts peak output) and so far it’s happy, through a good hour of conversations<\/p>\n","protected":false},"excerpt":{"rendered":"
The tests yesterday went well enough that I was comfortable getting on the air. So far the GaN FET is holding strong! I think the tweaks to the circuits improved efficiency (around 90% PAE I think) and removed the risk of a 200 amp current surge as it turned off. The Class F portion of […]<\/p>\n","protected":false},"author":1,"featured_media":155,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-154","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/posts\/154","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/comments?post=154"}],"version-history":[{"count":7,"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/posts\/154\/revisions"}],"predecessor-version":[{"id":165,"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/posts\/154\/revisions\/165"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/media\/155"}],"wp:attachment":[{"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/media?parent=154"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/categories?post=154"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai7sg.com\/index.php\/wp-json\/wp\/v2\/tags?post=154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}