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Electronics"},"subtitle":{"type":"html","$t":""},"link":[{"rel":"http://schemas.google.com/g/2005#feed","type":"application/atom+xml","href":"https:\/\/la3za.blogspot.com\/feeds\/posts\/default"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/-\/K2?alt=json-in-script\u0026max-results=5"},{"rel":"alternate","type":"text/html","href":"https:\/\/la3za.blogspot.com\/search\/label\/K2"},{"rel":"hub","href":"http://pubsubhubbub.appspot.com/"},{"rel":"next","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/-\/K2\/-\/K2?alt=json-in-script\u0026start-index=6\u0026max-results=5"}],"author":[{"name":{"$t":"Sverre Holm"},"uri":{"$t":"http:\/\/www.blogger.com\/profile\/08306221557326542499"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"26","height":"32","src":"\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEirIUQ4__tBn8iuiGzcRlJEOroeUKkNCZ2mN2DM3rs_2pPUFGIs7a2EtYWIiOikqsFchk8w4XaHx_XyS1g_-i8Kmu46zrppNaF1Xeh-omtKQqjq9tEzjhEobips8DmSvw\/s1600\/sverreholm20.jpg"}}],"generator":{"version":"7.00","uri":"http://www.blogger.com","$t":"Blogger"},"openSearch$totalResults":{"$t":"14"},"openSearch$startIndex":{"$t":"1"},"openSearch$itemsPerPage":{"$t":"5"},"entry":[{"id":{"$t":"tag:blogger.com,1999:blog-2554001380039969960.post-7908580463595632098"},"published":{"$t":"2022-06-14T20:14:00.012+02:00"},"updated":{"$t":"2023-05-21T20:38:25.044+02:00"},"category":[{"scheme":"http://www.blogger.com/atom/ns#","term":"K2"},{"scheme":"http://www.blogger.com/atom/ns#","term":"LA3ZA abroad"}],"title":{"type":"text","$t":"SV8\/LA3ZA part 2"},"content":{"type":"html","$t":"\u003Cdiv\u003E\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEj-pPzHbdZaKUxYHjiZaz67kXWrEt0EE29HyoDpnJRIcoYNUaducLNWKuIfAJp4I3gdu-TQDpXjb07JMlRTe0Y4d3t0rhRI2e6z-X0h0St7igJ9jPMsk2R3lTT17n_K5hiPDplYQJX8N8s6i83xcDv_Y-U8GQy0SML-F1JTDpQ4UvLdAO1g-IYUO2Fa\/s4608\/2022-06-12%2020.10.40.jpg\" style=\"clear: right; float: right; margin-bottom: 1em; margin-left: 1em;\"\u003E\u003Cimg border=\"0\" data-original-height=\"4608\" data-original-width=\"3456\" height=\"320\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEj-pPzHbdZaKUxYHjiZaz67kXWrEt0EE29HyoDpnJRIcoYNUaducLNWKuIfAJp4I3gdu-TQDpXjb07JMlRTe0Y4d3t0rhRI2e6z-X0h0St7igJ9jPMsk2R3lTT17n_K5hiPDplYQJX8N8s6i83xcDv_Y-U8GQy0SML-F1JTDpQ4UvLdAO1g-IYUO2Fa\/s320\/2022-06-12%2020.10.40.jpg\" width=\"240\" \/\u003E\u003C\/a\u003E\u003C\/div\u003EBelow is a map showing contacts made from Pythagorio, Samos, early June 2022 using FT8. I tried to contact as many entities (~countries) as possible and got to a total of 55. The main band was 30 m, secondarily 20 m. 40 m and 17 m were also used.\u0026nbsp;\u003C\/div\u003E\u003Cdiv\u003E\u003Cbr \/\u003E\u003C\/div\u003E\u003Cdiv\u003EMy quarter-wave antenna @ 30m, shown to the left in the image, performed well, despite the high noise level from the adjacent high-voltage line. The image is in the direction of Turkey (South-East), which is not visible at the time of the image.\u003C\/div\u003E\u003Cdiv\u003E\u003Cbr \/\u003E\u003C\/div\u003E\u003Cdiv\u003E\u003Cspan\u003E\u003Ca name='more'\u003E\u003C\/a\u003E\u003C\/span\u003EI tried 6 m also, but despite being able to tune the antenna for 6 m and that I heard stations, I never made a contact for that band.\u003C\/div\u003E\u003Cdiv\u003E\u003Cbr \/\u003E\u003C\/div\u003E\u003Cdiv\u003EOverall, I'm very happy with the result.\u003C\/div\u003E\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\u003Cbr \/\u003E\u003C\/div\u003E\u003Cbr \/\u003E\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEj-1zPQbVZPFB-Wsy2zjWWUDAthu45HoPSVwJvplQ3P-GoCQUmXTFD-b-cL-9Mxj9FjcnUQw_sp6K8sCLuNDVkoBy8lawDTAgPnB0cxkt1CiNwswcOjZ1j_pByMftUmdSN6zY-gyVzcoVr7FRLO4jMxYEbR_M5grKvqrB9ivCLg4YZ0x-vt3or7S4Xr\/s1905\/sv8-la3za-2022-06-12-55DXCC.png\" style=\"margin-left: 1em; margin-right: 1em;\"\u003E\u003Cimg border=\"0\" data-original-height=\"877\" data-original-width=\"1905\" height=\"184\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEj-1zPQbVZPFB-Wsy2zjWWUDAthu45HoPSVwJvplQ3P-GoCQUmXTFD-b-cL-9Mxj9FjcnUQw_sp6K8sCLuNDVkoBy8lawDTAgPnB0cxkt1CiNwswcOjZ1j_pByMftUmdSN6zY-gyVzcoVr7FRLO4jMxYEbR_M5grKvqrB9ivCLg4YZ0x-vt3or7S4Xr\/w400-h184\/sv8-la3za-2022-06-12-55DXCC.png\" width=\"400\" \/\u003E\u003C\/a\u003E\u003C\/div\u003E\u003Cbr \/\u003E\u003Cp\u003EThe log mapping tool was\u0026nbsp;\u003Ca href=\"http:\/\/qsomap.adventureradio.de\/\" target=\"_blank\"\u003EAdventureradio.de\u003C\/a\u003E\u003C\/p\u003E"},"link":[{"rel":"replies","type":"application/atom+xml","href":"https:\/\/la3za.blogspot.com\/feeds\/7908580463595632098\/comments\/default","title":"Post Comments"},{"rel":"replies","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2022\/06\/sv8la3za-part-2.html#comment-form","title":"0 Comments"},{"rel":"edit","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/7908580463595632098"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/7908580463595632098"},{"rel":"alternate","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2022\/06\/sv8la3za-part-2.html","title":"SV8\/LA3ZA part 2"}],"author":[{"name":{"$t":"Sverre Holm"},"uri":{"$t":"http:\/\/www.blogger.com\/profile\/08306221557326542499"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"26","height":"32","src":"\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEirIUQ4__tBn8iuiGzcRlJEOroeUKkNCZ2mN2DM3rs_2pPUFGIs7a2EtYWIiOikqsFchk8w4XaHx_XyS1g_-i8Kmu46zrppNaF1Xeh-omtKQqjq9tEzjhEobips8DmSvw\/s1600\/sverreholm20.jpg"}}],"media$thumbnail":{"xmlns$media":"http://search.yahoo.com/mrss/","url":"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEj-pPzHbdZaKUxYHjiZaz67kXWrEt0EE29HyoDpnJRIcoYNUaducLNWKuIfAJp4I3gdu-TQDpXjb07JMlRTe0Y4d3t0rhRI2e6z-X0h0St7igJ9jPMsk2R3lTT17n_K5hiPDplYQJX8N8s6i83xcDv_Y-U8GQy0SML-F1JTDpQ4UvLdAO1g-IYUO2Fa\/s72-c\/2022-06-12%2020.10.40.jpg","height":"72","width":"72"},"thr$total":{"$t":"0"}},{"id":{"$t":"tag:blogger.com,1999:blog-2554001380039969960.post-220888966311940361"},"published":{"$t":"2022-06-03T14:20:00.019+02:00"},"updated":{"$t":"2023-05-21T20:38:33.093+02:00"},"category":[{"scheme":"http://www.blogger.com/atom/ns#","term":"K2"},{"scheme":"http://www.blogger.com/atom/ns#","term":"LA3ZA abroad"}],"title":{"type":"text","$t":"SV8\/LA3ZA"},"content":{"type":"html","$t":"\u003Cp\u003E\u003C\/p\u003E\u003Ctable cellpadding=\"0\" cellspacing=\"0\" class=\"tr-caption-container\" style=\"float: right;\"\u003E\u003Ctbody\u003E\u003Ctr\u003E\u003Ctd style=\"text-align: center;\"\u003E\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhJYDUKAYWa6BZeiNlMRhUScPYhNTw3cpVCkmtyc_PCNhpKiqDeqBeG8xvMiula5moLVxafBt3cih6x7OkKdLl7u9LZcg12oDNkjsKhHanTikZPtXdtXN_y1Uz_extG3aagIAar0BIA-KH_xQTmiSGiY9ySiGfmvVF9nJb6nmp7TacceMwZslEmk0ax\/s2048\/Pythagoras.jpg\" style=\"clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;\"\u003E\u003Cimg border=\"0\" data-original-height=\"2048\" data-original-width=\"1536\" height=\"320\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhJYDUKAYWa6BZeiNlMRhUScPYhNTw3cpVCkmtyc_PCNhpKiqDeqBeG8xvMiula5moLVxafBt3cih6x7OkKdLl7u9LZcg12oDNkjsKhHanTikZPtXdtXN_y1Uz_extG3aagIAar0BIA-KH_xQTmiSGiY9ySiGfmvVF9nJb6nmp7TacceMwZslEmk0ax\/s320\/Pythagoras.jpg\" width=\"240\" \/\u003E\u003C\/a\u003E\u003C\/td\u003E\u003C\/tr\u003E\u003Ctr\u003E\u003Ctd class=\"tr-caption\" style=\"text-align: center;\"\u003EThe polymath Pythagoras was born on\u003Cbr \/\u003ESamos and his birthplace village is now\u003Cbr \/\u003Ecalled Pythagorio.\u003C\/td\u003E\u003C\/tr\u003E\u003C\/tbody\u003E\u003C\/table\u003EFor a short while I’m operating from \u003Ca href=\"https:\/\/www.qrz.com\/db\/SV5\/LA3ZA\" target=\"_blank\"\u003ESamos, Greece\u003C\/a\u003E with my old K2 at 10 W output. Noise level here next to a high voltage line is S9+ on all bands except 6m, so only digital modes work. The K2's noise blanker does a good job of removing some of the noise.\u003Cp\u003EThe antenna is a quarter-wave vertical for 30 m which also tunes several other bands. It’s on the balcony with a 7 m Sotabeam glass fiber mast, on the left-hand side of the street in the image below.\u003C\/p\u003E\u003Cspan\u003E\u003C\/span\u003E\u003Cspan\u003E\u003Ca name='more'\u003E\u003C\/a\u003E\u003C\/span\u003E\u003Cp\u003EI seem to be able to contact stations between Samos and the Netherlands, Canary Islands, and Saudi-Arabia as the longest distance. Considering that Pythagorio on Samos is facing south with a hill in the main direction towards Northern Europe, this isn't too bad.\u003C\/p\u003E\u003Cp\u003EI’m using a 10W\u0026nbsp;\u003Ca href=\"https:\/\/transverters-store.com\/\" target=\"_blank\"\u003EUT5JCW transverter\u003C\/a\u003E\u0026nbsp;for 6 m. Sadly, that business is now closed due to the war.\u003C\/p\u003E\u003Cp\u003EBy mistake I initially took the callsign to be SV5\/LA3ZA. As is evident from the comment below that is wrong, as I am one island or so too far North for that. I will unfortunately therefore not be able to confirm any of those contacts.\u003C\/p\u003E\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEi2yyg21n-oUyl2I1kWZDpWycUDEt3qYCu9695RlQcem9EiNRmDgLUECsFXAFjU1ym2elWJY_UvQ2BvyyQJisy7xVBF-briz2ef5X-ewgNBLpQbqy82wmidXoEn6j8BWygGgktPYipsxqccJBIh78b4KcRbhJFE7NzHAEym0GbFjWyuxIsdG-3rJtQv\/s2048\/9CB29BEE-9ADA-4FA6-AB8C-A8A9782884C9.jpeg\" style=\"margin-left: 1em; margin-right: 1em;\"\u003E\u003Cimg border=\"0\" data-original-height=\"1536\" data-original-width=\"2048\" height=\"240\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEi2yyg21n-oUyl2I1kWZDpWycUDEt3qYCu9695RlQcem9EiNRmDgLUECsFXAFjU1ym2elWJY_UvQ2BvyyQJisy7xVBF-briz2ef5X-ewgNBLpQbqy82wmidXoEn6j8BWygGgktPYipsxqccJBIh78b4KcRbhJFE7NzHAEym0GbFjWyuxIsdG-3rJtQv\/s320\/9CB29BEE-9ADA-4FA6-AB8C-A8A9782884C9.jpeg\" width=\"320\" \/\u003E\u003C\/a\u003E\u003C\/div\u003E\u003Cbr \/\u003E\u003Cp\u003E\u003Cbr \/\u003E\u003C\/p\u003E\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhzOl0aDlgT2dD0RzkG_A7duiwXW5J-H73NYjaY2XcB2Ba8YxF9saVWnZIAI3jt9tVbps1KF22kpKdSXmyNuS_aLvjWxKuumuP1ms8xNRZxpSYybsxijKLUcv2uZaQMWBw9rK6oNhfRyaAP6RemqtEV1yvmOw5kK-DIAhimUIguScg-vqdAxMghdxw-\/s2048\/2D5126C5-0E1D-4C77-A515-7D1CE947E747.jpeg\" style=\"margin-left: 1em; margin-right: 1em;\"\u003E\u003Cimg border=\"0\" data-original-height=\"2048\" data-original-width=\"1536\" height=\"320\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhzOl0aDlgT2dD0RzkG_A7duiwXW5J-H73NYjaY2XcB2Ba8YxF9saVWnZIAI3jt9tVbps1KF22kpKdSXmyNuS_aLvjWxKuumuP1ms8xNRZxpSYybsxijKLUcv2uZaQMWBw9rK6oNhfRyaAP6RemqtEV1yvmOw5kK-DIAhimUIguScg-vqdAxMghdxw-\/s320\/2D5126C5-0E1D-4C77-A515-7D1CE947E747.jpeg\" width=\"240\" \/\u003E\u003C\/a\u003E\u003C\/div\u003E\u003Cbr \/\u003E\u003Cp\u003E\u003Cbr \/\u003E\u003C\/p\u003E\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\u003Cbr \/\u003E\u003C\/div\u003E\u003Cbr \/\u003E\u003Cbr \/\u003E\u003C\/div\u003E\u003Cbr \/\u003E"},"link":[{"rel":"replies","type":"application/atom+xml","href":"https:\/\/la3za.blogspot.com\/feeds\/220888966311940361\/comments\/default","title":"Post Comments"},{"rel":"replies","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2022\/06\/sv5la3za.html#comment-form","title":"2 Comments"},{"rel":"edit","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/220888966311940361"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/220888966311940361"},{"rel":"alternate","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2022\/06\/sv5la3za.html","title":"SV8\/LA3ZA"}],"author":[{"name":{"$t":"Sverre Holm"},"uri":{"$t":"http:\/\/www.blogger.com\/profile\/08306221557326542499"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"26","height":"32","src":"\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEirIUQ4__tBn8iuiGzcRlJEOroeUKkNCZ2mN2DM3rs_2pPUFGIs7a2EtYWIiOikqsFchk8w4XaHx_XyS1g_-i8Kmu46zrppNaF1Xeh-omtKQqjq9tEzjhEobips8DmSvw\/s1600\/sverreholm20.jpg"}}],"media$thumbnail":{"xmlns$media":"http://search.yahoo.com/mrss/","url":"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhJYDUKAYWa6BZeiNlMRhUScPYhNTw3cpVCkmtyc_PCNhpKiqDeqBeG8xvMiula5moLVxafBt3cih6x7OkKdLl7u9LZcg12oDNkjsKhHanTikZPtXdtXN_y1Uz_extG3aagIAar0BIA-KH_xQTmiSGiY9ySiGfmvVF9nJb6nmp7TacceMwZslEmk0ax\/s72-c\/Pythagoras.jpg","height":"72","width":"72"},"thr$total":{"$t":"2"}},{"id":{"$t":"tag:blogger.com,1999:blog-2554001380039969960.post-9057272193027975711"},"published":{"$t":"2020-07-19T22:08:00.005+02:00"},"updated":{"$t":"2020-07-20T00:32:42.766+02:00"},"category":[{"scheme":"http://www.blogger.com/atom/ns#","term":"Digital mode"},{"scheme":"http://www.blogger.com/atom/ns#","term":"Elecraft"},{"scheme":"http://www.blogger.com/atom/ns#","term":"FT8"},{"scheme":"http://www.blogger.com/atom/ns#","term":"K2"}],"title":{"type":"text","$t":"Tweaking the K2 for digital modes "},"content":{"type":"html","$t":"My \u003Ca href=\"https:\/\/elecraft.com\/products\/k2-the-classic-hf-transceiver-full-kit\" target=\"_blank\"\u003EElecraft K2\u003C\/a\u003E\u0026nbsp;which I assembled as a kit in 2001, has mainly been a CW rig, but now I wanted to use it more for digital modes like FT8 also. That required some tweaking:\u003Cbr \/\u003E\n\u003Col\u003E\n\u003Cli\u003EWider bandwidth in SSB filter, so I took it from 2.4 to 2.6 kHz (KI6WX)\u003C\/li\u003E\n\u003Cli\u003EMore sensitive VOX (G3RXQ)\u003C\/li\u003E\n\u003Cli\u003ERF-filtering on audio input (G3RXQ)\u003C\/li\u003E\n\u003C\/ol\u003E\n\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\n\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhCarM_O0ufsWMINHWP2oXhca_gvyZwISWdZ74LEqt9GxWkBKXdNc5XpGeR2yOEpvFs67dQUsA6N-2JREoOZjID1m7NuVO1aRDjN5XFUc1XdrWb-1UbM9HeyPKCQfXTQutS-AiuHfMiNcU\/s1600\/KSB2-19-07-2020.png\" style=\"margin-left: 1em; margin-right: 1em;\"\u003E\u003Cimg border=\"0\" data-original-height=\"1151\" data-original-width=\"1600\" height=\"286\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhCarM_O0ufsWMINHWP2oXhca_gvyZwISWdZ74LEqt9GxWkBKXdNc5XpGeR2yOEpvFs67dQUsA6N-2JREoOZjID1m7NuVO1aRDjN5XFUc1XdrWb-1UbM9HeyPKCQfXTQutS-AiuHfMiNcU\/s400\/KSB2-19-07-2020.png\" width=\"400\" \/\u003E\u003C\/a\u003E\u003C\/div\u003E\n\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\n\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\nAll of these are modifications to the tighly packed KSB2 board shown above so it took some patience to implement them. The bandwidth modification consists in replacing six ceramic capacitors that were sitting between the crystals. The VOX sensitivity modification is done by adding a pot which can be seen in the image as it sits outside the PCB on the left-hand side. I was lucky to find a mini 5k slider pot in my junk box which fitted in. Finally the RF-filtering was done by adding an inductor of 2.5 mH (right below the 5k pot) and a decoupling capacitor.\u003Cbr \/\u003E\n\u003Ca name='more'\u003E\u003C\/a\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\nAll of these modifications can be found in the KSB2 section of the \u003Ca href=\"http:\/\/la3za.blogspot.com\/p\/la3za-unofficial-guide-to-elecraft-k2_28.html#KSB2\" target=\"_blank\"\u003Eguide to modifications\u003C\/a\u003E.\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\nThe barebone K2 has a limitation with continuous transmission and the manual says:\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cul\u003E\n\u003Cli\u003E\u003Ci\u003ESince some RTTY\/data mode duty cycles approach 100%, you should reduce power to about 5W or avoid transmitting at 10W for longer than 1-2 minutes at a time. (Power levels above 10 W are not recommended.)\u003C\/i\u003E\u0026nbsp;\u003C\/li\u003E\n\u003Cli\u003E\u003Ci\u003EDuty cycle 5 W, 100%; 10 W, 50%\u0026nbsp;\u003C\/i\u003E\u003C\/li\u003E\n\u003C\/ul\u003E\nThis should mean that it can do FT8 with its 12.6 seconds of transmission every 15 seconds at 10 W.\u0026nbsp;\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\nThe 100 W option, the KPA100, is more restricted and the manual says:\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cul\u003E\n\u003Cli\u003E\u003Ci\u003EThe maximum recommended power for PSK31 mode is 40 W, and for higher duty cycle modes such as MFSK, 25 W.\u003C\/i\u003E\u003C\/li\u003E\n\u003Cli\u003E\u003Ci\u003EKey-down time: At full power (100 W),\n10 sec max. recommended\u003C\/i\u003E\u003C\/li\u003E\n\u003C\/ul\u003E\n\u003Cdiv\u003E\nThe KPA100 can do FT4 at near 100 W it seems since it only transmits for 4.5 seconds, but not FT8.\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\nFinally, changing the SSB bandwidth meant that the BFO frequencies had to be set up again. It was fun to do this again as I haven't done it for many years now. Using the nice \u003Ca href=\"http:\/\/udel.edu\/~mm\/ham\/elecraft\/indexOpen.html\" target=\"_blank\"\u003EJava program from AB3AP\u003C\/a\u003E, K2Params, for reading the K2 Control parameters, I was also able to read out out the new values for backup. Some of them follow here. The \"RTTY rev\" mode is the preferred one for FT4 and FT8.\u003C\/div\u003E\n\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cdiv\u003E\n\u003Cb\u003EFilter settings:\u003C\/b\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; CW:\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;FL1 1.00C\u0026nbsp; \u0026nbsp;FL2 0.70C\u0026nbsp; \u0026nbsp;FL3 0.40C\u0026nbsp; \u0026nbsp;FL4 0.10C\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; CW rev:\u0026nbsp; \u0026nbsp;FL1 1.00C\u0026nbsp; \u0026nbsp;FL2 0.70C\u0026nbsp; \u0026nbsp;FL3 0.40C\u0026nbsp; \u0026nbsp;FL4 0.10C\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; LSB:\u0026nbsp; \u0026nbsp; \u0026nbsp; FL1 OP1L\u0026nbsp; \u0026nbsp; FL2 OP1L\u0026nbsp; \u0026nbsp; FL3 1.80L\u0026nbsp; \u0026nbsp;FL4 OFFL\u0026nbsp; \u0026nbsp;\u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; USB:\u0026nbsp; \u0026nbsp; \u0026nbsp; FL1 OP1U\u0026nbsp; \u0026nbsp; FL2 OP1U\u0026nbsp; \u0026nbsp; FL3 1.80U\u0026nbsp; \u0026nbsp;FL4 OFFU\u0026nbsp; \u0026nbsp;\u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; RTTY:\u0026nbsp; \u0026nbsp; \u0026nbsp;FL1 OP1R\u0026nbsp; \u0026nbsp; FL2 2.00R\u0026nbsp; \u0026nbsp;FL3 1.80R\u0026nbsp; \u0026nbsp;FL4 1.60R\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; RTTY rev: FL1 OP1R\u0026nbsp; \u0026nbsp; FL2 2.00R\u0026nbsp; \u0026nbsp;FL3 1.80R\u0026nbsp; \u0026nbsp;FL4 1.60R\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cb\u003EBFO settings:\u003C\/b\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; CW:\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;04913.33C\u0026nbsp; \u0026nbsp;04913.31C\u0026nbsp; \u0026nbsp;04913.22C\u0026nbsp; \u0026nbsp;04913.14C\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; CW rev:\u0026nbsp; \u0026nbsp;04914.46C\u0026nbsp; \u0026nbsp;04914.44C\u0026nbsp; \u0026nbsp;04914.25C\u0026nbsp; \u0026nbsp;04914.20C\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; LSB:\u0026nbsp; \u0026nbsp; \u0026nbsp; 04913.49L\u0026nbsp; \u0026nbsp;04913.71L\u0026nbsp; \u0026nbsp;04913.45L\u0026nbsp; \u0026nbsp;04913.54L\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; USB:\u0026nbsp; \u0026nbsp; \u0026nbsp; 04916.66U\u0026nbsp; \u0026nbsp;04916.45U\u0026nbsp; \u0026nbsp;04915.62U\u0026nbsp; \u0026nbsp;04916.10U\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; RTTY:\u0026nbsp; \u0026nbsp; \u0026nbsp;04913.55R\u0026nbsp; \u0026nbsp;04913.59R\u0026nbsp; \u0026nbsp;04913.59R\u0026nbsp; \u0026nbsp;04913.59R\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"font-family: \u0026quot;courier new\u0026quot;, courier, monospace;\"\u003E\u0026nbsp; RTTY rev: 04916.64R\u0026nbsp; \u0026nbsp;04915.97R\u0026nbsp; \u0026nbsp;04915.62R\u0026nbsp; \u0026nbsp;04915.44R\u0026nbsp; \u0026nbsp;\u003C\/span\u003E\u003C\/div\u003E\n\u003C\/div\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n\u003Cspan style=\"background-color: white; color: #333333; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px;\"\u003E\u003C\/span\u003E\u003Cbr \/\u003E\n\u003Cdiv\u003E\n\u003Cspan style=\"background-color: white; color: #333333; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px;\"\u003E\u003Cspan style=\"background-color: white; color: #333333; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px;\"\u003E\u003Cbr \/\u003E\u003C\/span\u003E\u003C\/span\u003E\u003C\/div\u003E\n\u003Cspan style=\"background-color: white; color: #333333; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px;\"\u003EThis\u0026nbsp;\u003C\/span\u003E\u003Ca href=\"http:\/\/la3za.blogspot.com\/2020\/07\/tweaking-k2-for-digital-modes.html\" style=\"background-color: white; color: #6699cc; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px;\"\u003Epost first appeared\u003C\/a\u003E\u003Cspan style=\"background-color: white; color: #333333; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px;\"\u003E\u0026nbsp;on the\u0026nbsp;\u003C\/span\u003E\u003Ca href=\"http:\/\/la3za.blogspot.com\/\" style=\"background-color: white; color: #6699cc; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px; text-decoration-line: none;\"\u003ELA3ZA blog\u003C\/a\u003E\u003Cspan style=\"background-color: white; color: #333333; font-family: arial, tahoma, helvetica, freesans, sans-serif; font-size: 14.85px;\"\u003E.\u003C\/span\u003E\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n\u003Cdiv\u003E\n\u003Cbr \/\u003E\u003C\/div\u003E\n"},"link":[{"rel":"replies","type":"application/atom+xml","href":"https:\/\/la3za.blogspot.com\/feeds\/9057272193027975711\/comments\/default","title":"Post Comments"},{"rel":"replies","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2020\/07\/tweaking-k2-for-digital-modes.html#comment-form","title":"0 Comments"},{"rel":"edit","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/9057272193027975711"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/9057272193027975711"},{"rel":"alternate","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2020\/07\/tweaking-k2-for-digital-modes.html","title":"Tweaking the K2 for digital modes "}],"author":[{"name":{"$t":"Sverre Holm"},"uri":{"$t":"http:\/\/www.blogger.com\/profile\/08306221557326542499"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"26","height":"32","src":"\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEirIUQ4__tBn8iuiGzcRlJEOroeUKkNCZ2mN2DM3rs_2pPUFGIs7a2EtYWIiOikqsFchk8w4XaHx_XyS1g_-i8Kmu46zrppNaF1Xeh-omtKQqjq9tEzjhEobips8DmSvw\/s1600\/sverreholm20.jpg"}}],"media$thumbnail":{"xmlns$media":"http://search.yahoo.com/mrss/","url":"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhCarM_O0ufsWMINHWP2oXhca_gvyZwISWdZ74LEqt9GxWkBKXdNc5XpGeR2yOEpvFs67dQUsA6N-2JREoOZjID1m7NuVO1aRDjN5XFUc1XdrWb-1UbM9HeyPKCQfXTQutS-AiuHfMiNcU\/s72-c\/KSB2-19-07-2020.png","height":"72","width":"72"},"thr$total":{"$t":"0"}},{"id":{"$t":"tag:blogger.com,1999:blog-2554001380039969960.post-8952874897436876983"},"published":{"$t":"2013-06-10T22:37:00.000+02:00"},"updated":{"$t":"2013-08-18T21:42:51.456+02:00"},"category":[{"scheme":"http://www.blogger.com/atom/ns#","term":"Elecraft"},{"scheme":"http://www.blogger.com/atom/ns#","term":"K2"},{"scheme":"http://www.blogger.com/atom/ns#","term":"QRP"}],"title":{"type":"text","$t":"Cosmetic K2 Upgrade"},"content":{"type":"html","$t":"\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\n\u003C\/div\u003E\n\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\n\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEg-rV9v_Cg_NVaiG6PdSNWCwS2WNOnIxe0JAxnu85Aur7Qq2BK0jEj2Pa8MDqg_hJPCWc2V8TgDRsP5-ficmmQbBxwjslULRGpAN9VcJ43pdZd-XUT_1PIYOcxaLQ7yNwmWHbSdYkmlH08\/s1600\/K2_newTuningKnob.jpg\" imageanchor=\"1\" style=\"clear: right; float: right; margin-bottom: 1em; margin-left: 1em;\"\u003E\u003Cimg border=\"0\" height=\"320\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEg-rV9v_Cg_NVaiG6PdSNWCwS2WNOnIxe0JAxnu85Aur7Qq2BK0jEj2Pa8MDqg_hJPCWc2V8TgDRsP5-ficmmQbBxwjslULRGpAN9VcJ43pdZd-XUT_1PIYOcxaLQ7yNwmWHbSdYkmlH08\/s320\/K2_newTuningKnob.jpg\" width=\"210\" \/\u003E\u003C\/a\u003E\u003C\/div\u003E\nMy Elecraft K2 which is now more than 11 years old (serial\u0026nbsp;#2198) has served me well, even earning me \u003Ca href=\"http:\/\/www.arrl.org\/qrp-dxcc\" target=\"_blank\"\u003EQRP DXCC\u003C\/a\u003E\u0026nbsp;(100 countries with 5 Watts) some years ago. It is still cosmetically in mint condition, except for that single item which sticks out like a sore thumb: The tuning knob.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\nThis became very clear to me a couple of months ago when LA8OKA's and my K2 were displayed side by side at our stand at \u003Ca href=\"http:\/\/oslomakerfaire.no\/\" target=\"_blank\"\u003EOslo Maker Faire\u003C\/a\u003E. His is less than two years old, serial\u0026nbsp;#7224, and they were similar except for the scratches in the faceplate of my tuning knob. If I am allowed to generalize from my knob only, it seems as if the faceplate had poor quality paint and has been replaced by a better quality version over the years.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\nAnyway I ordered a new one and paid the price which at present is $30.37 plus shipping. The difference is really striking and I feel like I have a new K2 now, well worth the price! The K2 now serves as my second rig, and I think it has many years of good service still to come.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\nRelated posts:\u003Cbr \/\u003E\n\u003Cul\u003E\n\u003Cli\u003E\u003Ca href=\"http:\/\/la3za.blogspot.no\/2011\/09\/elecraft-k2-dos-and-donts.html\" target=\"_blank\"\u003EElecraft K2 do's and don'ts\u003C\/a\u003E\u003C\/li\u003E\n\u003Cli\u003E\u003Ca href=\"http:\/\/la3za.blogspot.no\/2011\/05\/five-k2-leds-in-buttons.html\" target=\"_blank\"\u003EFive LEDs in buttons for the Elecraft K2\u003C\/a\u003E\u003C\/li\u003E\n\u003Cli\u003E\u003Ca href=\"http:\/\/la3za.blogspot.no\/2009\/06\/elecraft-k2-page.html\" target=\"_blank\"\u003EMy Elecraft K2 Modifications\u003C\/a\u003E\u003C\/li\u003E\n\u003C\/ul\u003E\n"},"link":[{"rel":"replies","type":"application/atom+xml","href":"https:\/\/la3za.blogspot.com\/feeds\/8952874897436876983\/comments\/default","title":"Post Comments"},{"rel":"replies","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2013\/06\/cosmetic-k2-upgrade.html#comment-form","title":"0 Comments"},{"rel":"edit","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/8952874897436876983"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/8952874897436876983"},{"rel":"alternate","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2013\/06\/cosmetic-k2-upgrade.html","title":"Cosmetic K2 Upgrade"}],"author":[{"name":{"$t":"Sverre Holm"},"uri":{"$t":"http:\/\/www.blogger.com\/profile\/08306221557326542499"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"26","height":"32","src":"\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEirIUQ4__tBn8iuiGzcRlJEOroeUKkNCZ2mN2DM3rs_2pPUFGIs7a2EtYWIiOikqsFchk8w4XaHx_XyS1g_-i8Kmu46zrppNaF1Xeh-omtKQqjq9tEzjhEobips8DmSvw\/s1600\/sverreholm20.jpg"}}],"media$thumbnail":{"xmlns$media":"http://search.yahoo.com/mrss/","url":"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEg-rV9v_Cg_NVaiG6PdSNWCwS2WNOnIxe0JAxnu85Aur7Qq2BK0jEj2Pa8MDqg_hJPCWc2V8TgDRsP5-ficmmQbBxwjslULRGpAN9VcJ43pdZd-XUT_1PIYOcxaLQ7yNwmWHbSdYkmlH08\/s72-c\/K2_newTuningKnob.jpg","height":"72","width":"72"},"thr$total":{"$t":"0"}},{"id":{"$t":"tag:blogger.com,1999:blog-2554001380039969960.post-7981901137556157621"},"published":{"$t":"2012-05-01T00:24:00.002+02:00"},"updated":{"$t":"2015-03-15T19:27:24.777+01:00"},"category":[{"scheme":"http://www.blogger.com/atom/ns#","term":"Elecraft"},{"scheme":"http://www.blogger.com/atom/ns#","term":"K2"},{"scheme":"http://www.blogger.com/atom/ns#","term":"Morse"}],"title":{"type":"text","$t":"Reliable auto-detect for keyer for Elecraft K2"},"content":{"type":"html","$t":"\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\n\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEgWeoyLa6cR93eWcHIkUwVFF6F46SOpg5sYwBnFkDk8_86PlO6cSWNb8R4UbIIRuCKSX8VKAN2ABcX00w5e999puCMkE4lLDsMD_-mtXEVtQgLG2dF0uNxqeVGJjN0fjhaegsG8WikwhbA\/s1600\/K2-ExternalKeyerAutodetect.png\" imageanchor=\"1\" style=\"clear: right; float: right; margin-bottom: 1em; margin-left: 1em;\"\u003E\u003Cimg border=\"0\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEgWeoyLa6cR93eWcHIkUwVFF6F46SOpg5sYwBnFkDk8_86PlO6cSWNb8R4UbIIRuCKSX8VKAN2ABcX00w5e999puCMkE4lLDsMD_-mtXEVtQgLG2dF0uNxqeVGJjN0fjhaegsG8WikwhbA\/s320\/K2-ExternalKeyerAutodetect.png\" height=\"218\" width=\"320\" \/\u003E\u003C\/a\u003E\u003C\/div\u003E\nThe Elecraft K2 has an autodetect feature for the keyer input. When enabled, and when the DASH and the DOT lines are keyed at exactly the same instant in time, the K2 will detect that this is a hand key or an external keyer. I and several other K2 owners have however experienced erratic action of the autodetect with seemingly random keying. \u003Cbr \/\u003E\n\u003Cbr \/\u003E\nMy problem only occurred when keying was done from an external keyer. This could happen when keying from e.g. the WinKeyer.\u003Cbr \/\u003E\n\u003Ca name='more'\u003E\u003C\/a\u003E\u003Cbr \/\u003E\nThe recommended circuit in the K2 manual is shown in the first figure. Two diodes make sure that the DOT and DASH lines are keyed in sync.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n\u003Cdiv class=\"separator\" style=\"clear: both; text-align: center;\"\u003E\n\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhDd1VZmUZCBiM6XCIpreqGOIZ_NingANcta6pEIqTVwMrtORRsqkfRqz3yJM9xoufLcVEtNuvudJZDMzDAMqmpQ5kFwRTb8SY_CHkERwCaKcRc8rViP5ympBY0UYHZuBLwrOZlgzG8A4o\/s1600\/K2-key-padle-input.png\" imageanchor=\"1\" style=\"clear: left; float: left; margin-bottom: 1em; margin-right: 1em;\"\u003E\u003Cimg border=\"0\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEhDd1VZmUZCBiM6XCIpreqGOIZ_NingANcta6pEIqTVwMrtORRsqkfRqz3yJM9xoufLcVEtNuvudJZDMzDAMqmpQ5kFwRTb8SY_CHkERwCaKcRc8rViP5ympBY0UYHZuBLwrOZlgzG8A4o\/s1600\/K2-key-padle-input.png\" \/\u003E\u003C\/a\u003E\u003C\/div\u003E\nThe keyer input from J1, the K2 key jack, goes through a low pass filter (220 ohm, 0.001 uF) for \ndebouncing\nand then on to the \/DASH and \/DOT-PTT lines which end up as inputs for the 18C452 MCU.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\nThe datasheet for the PIC processor states: \u003Ci\u003E\"Input low voltage 0.8V for 4.5V \u0026lt; VDD \u0026lt; 5.5V\"\u003C\/i\u003E\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n\u003Ca href=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEjW2a9UD2eT8a0qp2bsRpaR0fU5-koWG7wdFxv-q-tw1Ocp1yIgVVZ8jpbZyXpzGPcdqeq5bV2Qzjgs_hnpZjlkMyPK54v3KZ9Rko9jUpUeCTUcGzQ7UEmmB8TxACkmFLv-9lcBUb45eX4\/s1600\/K2-dash-dot-MCU.png\" imageanchor=\"1\" style=\"clear: right; float: right; margin-bottom: 1em; margin-left: 1em;\"\u003E\u003Cimg border=\"0\" src=\"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEjW2a9UD2eT8a0qp2bsRpaR0fU5-koWG7wdFxv-q-tw1Ocp1yIgVVZ8jpbZyXpzGPcdqeq5bV2Qzjgs_hnpZjlkMyPK54v3KZ9Rko9jUpUeCTUcGzQ7UEmmB8TxACkmFLv-9lcBUb45eX4\/s1600\/K2-dash-dot-MCU.png\" \/\u003E\u003C\/a\u003EThis value is rather high and could be the explanation for the erratic behavior. Use of the common 1N4148 silicon diodes in the autodetect circuit will make the K2 input no longer 0, but say 0.7 Volts when keyed. When I tried to key the K2 using autodetect and the diodes from my PC via an optocoupler I got into trouble. The saturation voltage of the optocoupler was not small enough and when added to the 0.7 Volts, the total was not low enough for the K2 to reliably sense a key-down.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\nThe optocoupler (4N31) had a voltage of 0.65 to 1.8 V in saturation. I lowered it by increasing the drive current in the LED, but still had almost 1.4 V (opto 0.65 + Si diode 0.7). \u003Cbr \/\u003E\n\u003Cbr \/\u003E\nThe remedy was to replace the autodetect diodes with Shottky diodes. One of the suggested diodes in the top figure, 1N5817, is actually a Shottky diode, but the importance of choosing such a diode rather than the common 1N4148 is not spelled out there. I have several hundreds of PRLL5818 in my shack so I used one of them, but the type is not critical at all. The data for that diode says Vf \u0026lt; 0.33 V at I = 100 mA, so the forward voltage with the low current here is even smaller than that.\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n[This post is an expansion of a \u003Ca href=\"http:\/\/marc.info\/?l=elecraft\u0026amp;m=111566641304665\u0026amp;w=2\" target=\"_blank\"\u003Eposting on the Elecraft mailing list\u003C\/a\u003E some time ago. All figures are from the Elecraft K2 manual.]\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n\u003Ca href=\"http:\/\/la3za.blogspot.no\/search\/label\/K2\" target=\"_blank\"\u003EOther Elecraft K2-related posts\u003C\/a\u003E\u003Cbr \/\u003E\n\u003Cbr \/\u003E"},"link":[{"rel":"replies","type":"application/atom+xml","href":"https:\/\/la3za.blogspot.com\/feeds\/7981901137556157621\/comments\/default","title":"Post Comments"},{"rel":"replies","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2012\/05\/reliable-auto-detect-for-keyer-for.html#comment-form","title":"0 Comments"},{"rel":"edit","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/7981901137556157621"},{"rel":"self","type":"application/atom+xml","href":"https:\/\/www.blogger.com\/feeds\/2554001380039969960\/posts\/default\/7981901137556157621"},{"rel":"alternate","type":"text/html","href":"https:\/\/la3za.blogspot.com\/2012\/05\/reliable-auto-detect-for-keyer-for.html","title":"Reliable auto-detect for keyer for Elecraft K2"}],"author":[{"name":{"$t":"Sverre Holm"},"uri":{"$t":"http:\/\/www.blogger.com\/profile\/08306221557326542499"},"email":{"$t":"noreply@blogger.com"},"gd$image":{"rel":"http://schemas.google.com/g/2005#thumbnail","width":"26","height":"32","src":"\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEirIUQ4__tBn8iuiGzcRlJEOroeUKkNCZ2mN2DM3rs_2pPUFGIs7a2EtYWIiOikqsFchk8w4XaHx_XyS1g_-i8Kmu46zrppNaF1Xeh-omtKQqjq9tEzjhEobips8DmSvw\/s1600\/sverreholm20.jpg"}}],"media$thumbnail":{"xmlns$media":"http://search.yahoo.com/mrss/","url":"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEgWeoyLa6cR93eWcHIkUwVFF6F46SOpg5sYwBnFkDk8_86PlO6cSWNb8R4UbIIRuCKSX8VKAN2ABcX00w5e999puCMkE4lLDsMD_-mtXEVtQgLG2dF0uNxqeVGJjN0fjhaegsG8WikwhbA\/s72-c\/K2-ExternalKeyerAutodetect.png","height":"72","width":"72"},"thr$total":{"$t":"0"}}]}});