{"id":152,"date":"2008-10-03T04:49:00","date_gmt":"2008-10-02T18:49:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2008\/10\/03\/flea-market-find-pi-net-tuner-with-a-mystery\/"},"modified":"2025-07-20T12:41:02","modified_gmt":"2025-07-20T02:41:02","slug":"flea-market-find-pi-net-tuner-with-a-mystery","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2008\/10\/03\/flea-market-find-pi-net-tuner-with-a-mystery\/","title":{"rendered":"Flea Market Find — Pi Net Tuner — With a Mystery"},"content":{"rendered":"

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\"\"<\/a>Last Sunday’s “Flea at Trastevere” (I’m the only one who calls it that) was a huge success for me. Minutes after arriving, amidst all the junk, Billy and I found this homebrew Pi network antenna tuner. The guy who sold it to me told me he had built it himself. The workmanship is top-notch. The quality of the parts is superb. There’s a built in SWR meter and a 10 db attenuator.<\/p>\n

When I started drawing out the schematic I noticed something weird: As the front panel indicates, it is a Pi -network, but for some reason the builder has the input variable cap floating. <\/span>The physical connection to the chassis is via insulators. The other variable cap has the standard mechanical and electrical connection to chassis ground. That input cap needs to be grounded too, correct? Why would this builder — who obviously knows his way around a soldering iron — go to the trouble of allowing that input cap to float?<\/p>\n","protected":false},"excerpt":{"rendered":"

Last Sunday’s “Flea at Trastevere” (I’m the only one who calls it that) was a huge success for me. Minutes after arriving, amidst all the junk, Billy and I found this homebrew Pi network antenna tuner. The guy who sold it to me told me he had built it himself. The workmanship is top-notch. The … Continue reading “Flea Market Find — Pi Net Tuner — With a Mystery”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":153,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[69,78],"tags":[],"class_list":["post-152","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-antennas","category-trastevere"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/152","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=152"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/152\/revisions"}],"predecessor-version":[{"id":155,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/152\/revisions\/155"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/153"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=152"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=152"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=152"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}