{"id":167,"date":"2024-09-24T10:54:00","date_gmt":"2024-09-24T00:54:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2024\/09\/24\/a-clean-vintage-ham-radio-transmitter-the-collins-32s-3\/"},"modified":"2025-07-22T18:01:20","modified_gmt":"2025-07-22T08:01:20","slug":"a-clean-vintage-ham-radio-transmitter-the-collins-32s-3","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2024\/09\/24\/a-clean-vintage-ham-radio-transmitter-the-collins-32s-3\/","title":{"rendered":"A Clean Vintage Ham Radio Transmitter: The Collins 32S-3"},"content":{"rendered":"<\/p>\n
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In an article on IMD and splatter, tech guru Rob Sherwood noted that the cleanest tranmitter he had ever owened was the Colling 32S-3. Here is the article. https:\/\/soldersmoke.blogspot.com\/2024\/09\/sherwood-its-time-to-clean-up-our.html<\/a><\/b><\/div>\n
In it, you will see thar Rob has the spectrum anayser two tone test to prove his point. <\/b><\/div>\n

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This got me wondering: Why was the Collins transmitter so clean. Today I looked at some ot the tech info on this rig. I think I have found the answer. The Collins Collectors Association has a great page on the 32S-3: https:\/\/collinsradio.org\/cca-collins-historical-archives\/the-equipment-of-collins-radio\/the-grey-boxes\/32s-3\/<\/a><\/b><\/div>\n

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The key lines are these: <\/b><\/div>\n

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Click on the paragraphs or go to the link for a clearer view <\/span><\/div>\n
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I think the explanation of Collins’32S-3 cleanliness is due to 1) Thermatrons in the final stages and 2) Negative feedback to take down any IMD products that might appear due to non-linearities in the finals. <\/b><\/div>\n

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There is nothing magical in that technique. Heck, we could homebrew that today. We could build HDR stations (perhaps transistor-tube hybrids) that would be cleaner than their commercial SDR cousins. <\/b><\/div><\/p>\n","protected":false},"excerpt":{"rendered":"

In an article on IMD and splatter, tech guru Rob Sherwood noted that the cleanest tranmitter he had ever owened was the Colling 32S-3. Here is the article. https:\/\/soldersmoke.blogspot.com\/2024\/09\/sherwood-its-time-to-clean-up-our.html In it, you will see thar Rob has the spectrum anayser two tone test to prove his point. This got me wondering: Why was the Collins … Continue reading “A Clean Vintage Ham Radio Transmitter: The Collins 32S-3”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":168,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[84,76,23],"tags":[],"class_list":["post-167","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-amplifier-theory","category-collins-art","category-ssb"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/167","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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/comments?post=167"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/167\/revisions"}],"predecessor-version":[{"id":171,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/167\/revisions\/171"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/168"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=167"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=167"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=167"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}