{"id":8147,"date":"2016-07-18T10:48:00","date_gmt":"2016-07-18T00:48:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2016\/07\/18\/building-a-vfo-a-big-vfo-if-options\/"},"modified":"2025-07-22T00:07:44","modified_gmt":"2025-07-21T14:07:44","slug":"building-a-vfo-a-big-vfo-if-options","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2016\/07\/18\/building-a-vfo-a-big-vfo-if-options\/","title":{"rendered":"Building a VFO. A BIG VFO. IF options?"},"content":{"rendered":"
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Once again, The Radio Gods have Spoken (TRGHS). An off-hand comment at the Manassas Hamfest, a bit of encouragement from Pete Juliano, and the next thing you know Armand WA1UQO has sent me this beautiful National HRO dial and reduction drive. This thing is so nice… Well, put it this way: this is the first time I’m building a rig around the dial! <\/b><\/div>\n

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Further evidence that TRGHS: I needed something on which to base the HRO dial and a box for the VFO. Wouldn’t you know it: That Whole Foods “grilling plank” that I bought a few weeks ago was PERFECTLY sized for this task. Eerie, don’t you think? As for the VFO box, well TRGHS again: pictured above you see a side view of the box from one of the Heath QF-1 Q multipliers that I cannibalized for the variable caps. Finally, for the main tuning cap, I took another look at that old brass variable cap that I took out of a 1930’s era British regen (pictured above). It had been hopelessly stuck for a long time. I twisted it a bit and was amazed to see that it is stuck no more. TRGHS! (I just need to find a suitable nut so that I can mount the old cap in the QF-1 box.) <\/b><\/div>\n

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I’m thinking that this VFO will be the heart of a general coverage shortwave superhet receiver. I want filters for AM and SSB and I’d like it to cover 5 MHz to 10 MHz. I’ve been noodling various IF possibilities, but concerns about birdies and spurs keep driving me back to 455 kHz. I have a crystal-mechanical filter for that freq. And a big box of 455 kc transformers. What do you guys think of this option? <\/b><\/div>\n

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Once again, The Radio Gods have Spoken (TRGHS). An off-hand comment at the Manassas Hamfest, a bit of encouragement from Pete Juliano, and the next thing you know Armand WA1UQO has sent me this beautiful National HRO dial and reduction drive. This thing is so nice… Well, put it this way: this is the first … Continue reading “Building a VFO. A BIG VFO. IF options?”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":8148,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[321,133,41,100,57],"tags":[],"class_list":["post-8147","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hamel-armand","category-hamfests-and-flea-markets","category-juliano-pete","category-old-radio","category-superhet-receivers"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/8147","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=8147"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/8147\/revisions"}],"predecessor-version":[{"id":8149,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/8147\/revisions\/8149"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/8148"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=8147"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=8147"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=8147"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}