{"id":10227,"date":"2009-04-10T14:50:00","date_gmt":"2009-04-10T04:50:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2009\/04\/10\/parachutes-and-qrss\/"},"modified":"2025-07-22T04:04:44","modified_gmt":"2025-07-21T18:04:44","slug":"parachutes-and-qrss","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2009\/04\/10\/parachutes-and-qrss\/","title":{"rendered":"Parachutes and QRSS"},"content":{"rendered":"

Kevin, AA7YQ, has made innovative use of a parachute. You are right Kevin, this must be a first:
<\/span><\/span>\"\"<\/a>
Howdy Bill,<\/span><\/span><\/span> <\/span>It\u2019s Kevin here in <\/span><\/span>Montana<\/span><\/span><\/span>, the ex-Smokejumper. I\u2019ve been meaning to write again. Thanks for the nice comment on SS #100 I got a kick out of it. Anyhow, just thought I\u2019d drop you a note to let you know I finally had a weekend to design and build up a QRSS beacon. I used a Cypress PSoC CY24123A uC to function as the Crystal Oscillator<\/span>, and keyer. The final is two paralleled BS-170 MOSFETs running in Class-E mode to give me about 560mW out with a 7.5volt Lantern battery as my supply, total system power efficiency is about 63%(RFout over DC in), I\u2019m sure this could be significantly improved, but good enough for now. After several hours of tweaking the capacitor values I finally got the oscillator to fall into the 100Hz window. That was MUCH harder than I had anticipated. With the original version I switched the PA on and off for true QRSS 3 CW, but found this made a significant frequency drift<\/span> problem. So I added a couple parts and modified the PSoC code a bit, now its running CWFSK, switching about 1.1pF on and off one leg of the XTAL, shifting the frequency about 10Hz and much more stable. <\/span><\/span><\/p>\n

\n
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My first tests were with the board sitting on the bench under the desk lamp. This caused all kinds of drift problems. I then put the beacon in a Tupperware container and placed it inside a soft case cooler. I was looking around the shack for a blanket or something to further improve the insulation, when low and behold sitting in a garbage sack\u2026 was a condemned FS-14 parachute (equivalent to the SF-10A) that I was planning using for something useful. So I wrapped the chute around the cooler and stuffed it all back in the garbage sack. Surprisingly, temperature stabilization was achieved, beyond my expectations.<\/span><\/span><\/p>\n

The beacon is running good now, nice and stable. I\u2019m fairly certain, that in the history of mankind, no one has ever used a parachute to improve the temperature drift characteristics of a QRSS beacon. Anyhow, I plan on having it fired up quite a bit, so that my antenna is actually put to some good use. It seems I rarely get a chance for one to one contacts anymore. Most of my free time is spent designing and building the radios I never use. Ha. I guess the design and building is the real fun for me. <\/span><\/span><\/p>\n

Anyhow, I\u2019ll talk to you later. 73s Kevin, AA7YQ<\/span><\/span><\/p>\n

PS the Beacon is sending \u201cAA7YQ\u201d followed by a several second pause. It\u2019s showing up on the K6HX grabber between 10.140050 and 10.140060.<\/span><\/span><\/p>\n<\/p><\/div>\n<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

Kevin, AA7YQ, has made innovative use of a parachute. You are right Kevin, this must be a first: Howdy Bill, It\u2019s Kevin here in Montana, the ex-Smokejumper. I\u2019ve been meaning to write again. Thanks for the nice comment on SS #100 I got a kick out of it. Anyhow, just thought I\u2019d drop you a … Continue reading “Parachutes and QRSS”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":8751,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[286,165],"tags":[],"class_list":["post-10227","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-parachute","category-qrss"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10227","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=10227"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10227\/revisions"}],"predecessor-version":[{"id":10228,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/10227\/revisions\/10228"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/8751"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=10227"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=10227"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=10227"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}