{"id":4586,"date":"2008-11-15T13:10:00","date_gmt":"2008-11-15T02:10:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2008\/11\/15\/amplifier-for-80-meter-rig\/"},"modified":"2025-07-21T17:27:10","modified_gmt":"2025-07-21T07:27:10","slug":"amplifier-for-80-meter-rig","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2008\/11\/15\/amplifier-for-80-meter-rig\/","title":{"rendered":"Amplifier for 80 Meter Rig"},"content":{"rendered":"

\"\"<\/a>Here’s the LTSpice schematic for an amplifier chain that I’ve been building. (It might be hard to see, but maybe you can download it and look at a larger version.) Four stages, all feedback amps. The first three are class A, the final is Class AB. About 45 db total power gain — it takes the .0001 watt (peak) from my balanced modulator and amplifies it to about 3.2 watts.<\/p>\n

So far it seems very stable. Notice that I don’t have any decoupling networks on the first three stages (other than a .1 uF cap to ground on the +13V supply rail. I tried to continue without decoupling on the final, but I got instability, so I added a 10 uH RF choke and a cap to ground as a decoupling network to the final stage. Instability disappeared. Do I need more decoupling on the other three stages?<\/p>\n

The last two transistors are disgnated at 2N3053 and 2SC2075. That’s what I’m actually using, but I haven’t figured out how to get these parts into LTSpice, so I’m actually using 2N2222 models in my simulation.<\/p>\n

Here is the actual LTSpice file: Bill’s Kickpanel amplifiers<\/a><\/p>\n

I’ll talk about this project on SolderSmoke tomorrow. Comments welcome.<\/p>\n","protected":false},"excerpt":{"rendered":"

Here’s the LTSpice schematic for an amplifier chain that I’ve been building. (It might be hard to see, but maybe you can download it and look at a larger version.) Four stages, all feedback amps. The first three are class A, the final is Class AB. About 45 db total power gain — it takes … Continue reading “Amplifier for 80 Meter Rig”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":4587,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-4586","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4586","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=4586"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4586\/revisions"}],"predecessor-version":[{"id":4588,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4586\/revisions\/4588"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/4587"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=4586"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=4586"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=4586"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}