{"id":4346,"date":"2020-07-22T18:20:00","date_gmt":"2020-07-22T08:20:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2020\/07\/22\/ke5hpys-12au7-quarantine-regen-fb\/"},"modified":"2025-07-21T16:58:43","modified_gmt":"2025-07-21T06:58:43","slug":"ke5hpys-12au7-quarantine-regen-fb","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2020\/07\/22\/ke5hpys-12au7-quarantine-regen-fb\/","title":{"rendered":"KE5HPY’s 12AU7 Quarantine Regen — FB!"},"content":{"rendered":"
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Bill and Pete:<\/b><\/div>\n
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Thanks for upping the frequency of your podcasts. Each one is a welcome note to break-up the COVID monotony.<\/b><\/div>\n
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Following on to Bill\u2019s 31m rx, I am pleased to have a new regen on the air and performing well. This started as the 12AU7 Hartley circuit found on the web; however, the original circuit needed some further work IMO. I made a number of modifications \u2013 outboard 30 MHz LPF (to remove our local Spanish FM station), inductive antenna link, variable cap for antenna coupling adjustment, up to 24V on the plate, extra by-passing, NE5532 audio section vs LM386 and a switched cap for a lower \u201cband\u201d. It\u2019s still a starved triode oscillator\/audio amp and it has that regen presence. Best DX is Singapore (BBC) and Madagascar although it\u2019s ideal for easy listening on 19-60m to Romania, Greece, Cuban music, Spain, etc. As Bill said, there is still plenty worth listening to on a homebrew AM rx. 40, 30 and 20m copy OK, but bandspread is tricky! Adjusting regen is good for +\/- 1 kHz, kind of a poor man\u2019s BFO adjustment. I heard a TI station calling CQ on 20m and called him back on my Icom for a QSO. <\/b><\/div>\n
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By the way, this rx has some serious vintage mojo \u2013 Hammarlund varicap, National coil form, Millen dial and an RCA tube. The all-star team plays great together! It\u2019s a kick seeing the filament glow while putting RF through recycled parts made decades ago.<\/b><\/div>\n
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73,<\/b><\/div>\n
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Chuck<\/b><\/div>\n
KE5HPY<\/b><\/div>\n
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Bill and Pete: Thanks for upping the frequency of your podcasts. Each one is a welcome note to break-up the COVID monotony. Following on to Bill\u2019s 31m rx, I am pleased to have a new regen on the air and performing well. This started as the 12AU7 Hartley circuit found on the web; however, the … Continue reading “KE5HPY’s 12AU7 Quarantine Regen — FB!”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":4347,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[270,148,72,101],"tags":[],"class_list":["post-4346","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-quarantine","category-regens","category-short-wave-listening","category-tubes"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4346","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=4346"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4346\/revisions"}],"predecessor-version":[{"id":4349,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4346\/revisions\/4349"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/4347"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=4346"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=4346"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=4346"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}