{"id":19464,"date":"2023-11-27T17:11:09","date_gmt":"2023-11-28T01:11:09","guid":{"rendered":"https:\/\/rustybolt.info\/wordpress\/?p=19464"},"modified":"2023-11-28T20:20:45","modified_gmt":"2023-11-29T04:20:45","slug":"2023-11-27-tbd-2","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=19464","title":{"rendered":"2023-11-27 RCA BFO Audio Oscillator Photos"},"content":{"rendered":"\n

Chuck commented about the audio oscillator being a BFO, and it reminded me that I’ve got an old RCA BFO audio oscillator stuck away in the garage. It was a cheap way of getting an audio sine wave that covered the full audio band without any switching. Nowadays it’s all done in sine and other waveforms by a function generator, up to 2 MHz or more.

So I dragged the old clunker out and took some photos. Sadly, when I got it the power transformer was melted and dripping tar. So it’s never worked for me. And it was missing its tubes – no worry, they’re marked on the chassis. This is probably the first and last time you’ll ever see one of these. Almost all the tech benches had a HP 200 audio generator, so why bother with cheap RCA equipment? 👍

The front face and dial would look impressive if it was cleaned up. But I’ll let someone else do that. I’ve got a half dozen function generators that need to be fixed. When was the last time you saw one of those chassis mounted power resistors with multiple taps on it? I don’t have a schematic but I would guess that the taps are for screen grids? Or just lower voltage B+? <\/p>\n\n\n\n

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These and a few more were posted to Facebook.<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"

Chuck commented about the audio oscillator being a BFO, and it reminded me that I’ve got an old RCA BFO audio oscillator stuck away in the garage. It was a cheap way of getting an audio sine wave that covered the full audio band without any switching. Nowadays it’s all done in sine and other <\/p>\n

(Read More…)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,339,17,357,330,337],"tags":[3014,3013,3012,3011],"class_list":["post-19464","post","type-post","status-publish","format-standard","hentry","category-audio","category-generators-oscillators","category-meters-and-test-equipment","category-modification","category-oscillators","category-vacuum-tubes","tag-audio-generator","tag-beat-frequency-oscillator","tag-bfo","tag-rca"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/19464","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=19464"}],"version-history":[{"count":2,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/19464\/revisions"}],"predecessor-version":[{"id":19474,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/19464\/revisions\/19474"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}