{"id":44439,"date":"2017-01-10T22:03:06","date_gmt":"2017-01-10T20:03:06","guid":{"rendered":"http:\/\/www.cqdx.ru\/ham\/?p=44439"},"modified":"2023-09-24T16:10:44","modified_gmt":"2023-09-24T16:10:44","slug":"new-digital-modes-gain-traction-for-moonbounce-but","status":"publish","type":"post","link":"https:\/\/www.cqdx.ru\/ham\/ham-radio-news\/new-digital-modes-gain-traction-for-moonbounce-but\/","title":{"rendered":"New Digital Modes Gain Traction for Moonbounce, but …"},"content":{"rendered":"

New Digital Modes Gain Traction for Moonbounce, but Occasionally Show Up on HF.<\/strong><\/p>\n

In December, Joe Taylor, K1JT, released the latest version (1.7) of his WSJT-X<\/a><\/i><\/strong> software suite, designed to facilitate basic Amateur Radio communication using very weak signals (WSJT<\/i> stands for \u201cWeak Signal communication by K1JT\u201d). Version 1.7 included the new modes MSK144<\/i> and QRA64<\/i>, as well as ISCAT<\/i> (ionospheric scatter). MSK144<\/i> and QRA64<\/i> (and QRA64A<\/i>) are finding a home within the VHF Earth-Moon-Earth (EME, or moonbounce) and meteor-scatter communities, but QRA64A<\/i> signals also have turned up on 160 meters, which poses its own challenges to weak signals.<\/p>\n

\u201cQRA64A<\/i> QSOs are being made nightly on 160 meters, of all places, and QRA64<\/i> activity on 2-meter EME is becoming significant, especially on weekends,\u201d Taylor remarked in a January 9 update posted to the Moon-Net reflector, pointing out that QRA64<\/i> is decoding signals down to about \u201328 dB signal-to-noise.<\/p>\n

But Taylor does not advise a wholesale shift to the use of QRA64<\/i> on the HF bands \u2014 at least just yet. \u201cIt\u2019s okay to play with and test QRA64<\/i> at HF, if you wish,\u201d he commented recently on the WSJT Development<\/strong><\/a> discussion group. \u201cSome of our earliest tests of the mode were done on the 20-meter and 30-meter bands.\u201d He suggested, though, that HF operators stick with JT65<\/i>, \u201cnot least because, at present, we have included no \u2018multi-decode\u2019 capability for the QRA64<\/i> decoder. It\u2019s made to decode just one signal in the passband.\u201d<\/p>\n

\"\"<\/a><\/p>\n

In the WSJT-X<\/i> Version 1.7 User Guide<\/strong><\/a>, Taylor pointed out QRA64<\/i>\u2019s several advantages over JT65<\/i>, including better performance on the very weakest signals. \u201cWe imagine that, over time, it may replace JT65<\/i> for EME use,\u201d he wrote. \u201cJT9<\/i> was originally designed for the LF, MF, and lower HF bands. Its submode JT9A<\/i> is 2 dB more sensitive than JT65<\/i>, while using less than 10% of the bandwidth.\u201d<\/p>\n

Taylor told ARRL that he expects JT65<\/i> and JT9<\/i> to remain the preferred modes for making \u201cminimal QSOs\u201d at HF for some years to come. \u201cQRA64<\/i> is 1-3 dB more sensitive than JT65<\/i> or JT9<\/i>; this is important for EME, but much less so at HF, because one can usually run 20 W instead of 10 W, when the going gets rough.\u201d<\/p>\n

These modes use 1-minute timed sequences of alternating transmission and reception, so a basic contact can take up to 6 minutes \u2014 two or three transmissions by each station, one transmitting on odd UTC minutes and the other on even.<\/p>\n

Taylor said that MSK144<\/i> \u201cis quickly becoming the<\/i> mode for meteor scatter,\u201d at least in North America and Europe. \u201cUnlike FSK441<\/i> \u2014 the older standard mode for meteor scatter \u2014 MSK144<\/i> uses strong error correction and JT65<\/i>-like messages. Messages are displayed in complete form or not at all, and false decodes are rare. Last week, we introduced an \u2018SWL\u2019 feature that allows decoding of MSK144<\/i> \u2018Sh\u2019 (short) messages directed to someone other than yourself.\u201d<\/p>\n

Source: ARRL<\/p>\n","protected":false},"excerpt":{"rendered":"

New Digital Modes Gain Traction for Moonbounce, but Occasionally Show Up on HF. In December, Joe Taylor, K1JT, released the latest version (1.7) of his WSJT-X software suite, designed to facilitate basic Amateur Radio communication using very weak signals (WSJT stands for \u201cWeak Signal communication by K1JT\u201d). Version 1.7 included the new modes MSK144 and…<\/p>\n","protected":false},"author":2,"featured_media":44440,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[5],"tags":[190,195,203,234],"class_list":["post-44439","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ham-radio-news","tag-ham","tag-ham-radio","tag-hamradio","tag-info","category-5","description-off"],"_links":{"self":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/posts\/44439","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/comments?post=44439"}],"version-history":[{"count":0,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/posts\/44439\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/media\/44440"}],"wp:attachment":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/media?parent=44439"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/categories?post=44439"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/tags?post=44439"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}