{"id":981,"date":"2015-07-09T09:21:26","date_gmt":"2015-07-09T00:21:26","guid":{"rendered":"https:\/\/jg7sfr.mydns.jp\/?p=981"},"modified":"2016-04-07T12:48:44","modified_gmt":"2016-04-07T03:48:44","slug":"s%e3%83%a1%e3%83%bc%e3%82%bf%e3%83%bc%e3%81%a8dbm","status":"publish","type":"post","link":"https:\/\/jg7sfr.mydns.jp\/?p=981","title":{"rendered":"S\u30e1\u30fc\u30bf\u30fc\u3068dBm"},"content":{"rendered":"

\u5148\u305a\u306f\u30ea\u30cb\u30a2\u30c6\u30af\u30ce\u30ed\u30b8\u30fc\u69d8\u306e\u8cc7\u6599\u3088\u308a<\/a>
\n\u3053\u306e\u8cc7\u6599\u304b\u3089\u4e00\u90e8\u629c\u7c8b\u3055\u305b\u3066\u3044\u305f\u3060\u304d\u307e\u3057\u305f\u3002
\n\"dBm-dBu\"<\/a><\/p>\n

50\u03a9\u3067\u306f0dBm=223.8mV\u3002S\u30e1\u30fc\u30bf\u30fc\u306eS9\u306f50\u03bcV\u3089\u3057\u3044\u3002
\nGv=20log(223.8\/0.050)=73dBm<\/p>\n

dB\u03bc\u3068\u306e\u95a2\u4fc2\u306f
\n0dBm=113dB\u03bc(EMF),107dB\u03bc(PD)\u3068\u306e\u4e8b\u3002<\/p>\n

EMF >> Potential Difference >> \u8ca0\u8377\u30a4\u30f3\u30d4\u30fc\u30c0\u30f3\u30b9\u3067\u7d42\u7aef\u3002
\nPD >>> Electro Motive Force >> \u8ca0\u8377\u304c\u7121\u3044\u72b6\u614b\u3002\u958b\u653e\u3002
\nEMF=2*PD(\u96fb\u5727\u8868\u8a18)\u3001EMF=PD+6dB(dB\u8868\u8a18)<\/p>\n

0dB\u03bc\uff1d1\u03bcV\uff0c60dB\u03bc\uff1d1mV
\n\u3053\u3053\u307e\u3067\u6765\u308b\u3068\u96e3\u3057\u3044\u3067\u3059\u306d\u3002\u4f3c\u305f\u3088\u3046\u306a\u5358\u4f4d\u3067\u306f\u3042\u308a\u307e\u3059\u304c\u3002
\ndBm\u306f1mW\u57fa\u6e96\u3002dB\u03bc\u306f
\nGigaSt\u3067\u5e38\u6642-12dB\u3092\u8a2d\u5b9a\u3057\u3066\u3044\u305f\u3002
\n-12dB\u3092\u8003\u616e\u3057\u306a\u3044\u5834\u5408\u3001SG\u2192ATT(0dB)\u2192\u30b9\u30da\u30a2\u30ca\u3067-60dB\u3053\u308c\u3092
\nSG\u2192ATT(25dB\u304f\u3089\u3044)\u2192\u30ea\u30b0\u3068\u3059\u308b\u3068\u3001\u6982\u306dS9\u3060\u3063\u305f\u3002-60-25=-85dB
\n-12dB\u3092\u8003\u616e\u3059\u308b\u3068\u3001-73dB\u3068\u306a\u308a\u3001\u6848\u5916\u3001GigaSt\u3082\u6b63\u78ba?\u3068\u95a2\u5fc3\u3002
\n\u9060\u304b\u3089\u305a\u3068\u3082\u30fb\u30fb\u30fb\u306a\u306e\u3067\u3057\u3087\u3046\u3002
\nTS-50\u306e28MHz\u3067\u3082\u8a66\u3059\u3068\u8fd1\u3044\u7d50\u679c\u304c\u5f97\u3089\u308c\u305f\u3002
\nS\u30e1\u30fc\u30bf\u30fc\u3001\u8abf\u6574\u3057\u306a\u304f\u3066\u3082\u5927\u4e08\u592b\u304b\u3082\u3057\u308c\u306a\u3044\u3002<\/p>\n

S\u304c\u4e00\u3064\u4e0b\u304c\u308b\u3068S9\u2192S8\u306750\u03bcV\u219225\u03bcV(-73dBm\u2192-79dBm\u3068-6dBm\u4e0b\u304c\u308b)
\n0dBm(223.8mV)
\nHF
\nS9+60dB >> 50.1mV(-13dBm)
\nS9+40dB >> 5.01mV(-33dBm)
\nS9+20dB >> 501\u03bcV(-53dBm)
\nS9 >>>>>>> 50.0\u03bcV(-73dBm)
\nS8 >>>>>>> 25.0\u03bcV(-79dBm)
\nS7 >>>>>>> 12.5\u03bcV(-85dBm)
\nS6 >>>>>>> 6.25\u03bcV(-91dBm)
\nS5 >>>>>>> 3.125\u03bcV(-97dBm)
\nS4 >>>>>>> 1.562\u03bcV(-103dBm)
\nS3 >>>>>>> 0.781\u03bcV(-109dBm)
\nS2 >>>>>>> 0.390\u03bcV(-115dBm)
\nS1 >>>>>>> 0.195\u03bcV(-121dBm)
\nS0 >>>>>>> 0.097\u03bcV(-127dBm)<\/p>\n

VHF
\nS9+60dB >> 5.01mV(-33dBm)
\nS9+40dB >> 501\u03bcV(-53dBm)
\nS9+20dB >> 50.1\u03bcV(-73dBm)
\nS9 >>>>>>> 5.01\u03bcV(-93dBm)
\nS8 >>>>>>> 2.51\u03bcV(-99dBm)
\nS7 >>>>>>> 1.25\u03bcV(-105dBm)
\nS6 >>>>>>> 0.63\u03bcV(-111dBm)
\nS5 >>>>>>> 0.31\u03bcV(-117dBm)
\nS4 >>>>>>> 0.16\u03bcV(-123dBm)
\nS3 >>>>>>> 0.08\u03bcV(-129dBm)
\nS2 >>>>>>> 0.04\u03bcV(-135dBm)
\nS1 >>>>>>> 0.02\u03bcV(-141dBm)
\nS0 >>>>>>> 0.01\u03bcV(-147dBm)<\/p>\n

GigaSt\u3067\u306f\u30ce\u30a4\u30ba\u306e\u5e95\u306b\u96a0\u308c\u3066\u3001-70dB\u524d\u5f8c\u306f\u78ba\u8a8d\u3067\u304d\u306a\u3044\u3002
\n\u3051\u308c\u3069\u3082GigaSt\u306eSG\u304b\u3089\u306f\u78ba\u5b9f\u306b\u4fe1\u53f7\u306f\u30ea\u30b0\u306b\u5c4a\u3044\u3066\u3044\u305f\u4e8b\u304c\u78ba\u8a8d\u3067\u304d\u305f\u3002
\nSG\u306f\u5fc5\u8981\u306a\u3044\u304b\u306a\u3002\u3063\u3066\u8cb7\u3048\u307e\u305b\u3093\u304c\u3002
\n\u51fa\u6765\u308b\u308b\u3053\u3068\u306a\u3089\u5468\u6ce2\u6570\u306e\u9ad8\u3044\u30aa\u30b7\u30ed\u304c\u6b32\u3057\u3044\u3068\u3053\u308d\u3002
\n50MHz\u306f\u30a2\u30f3\u30c6\u30ca\u304c\u5927\u304d\u3044\u306e\u3067\u3001\u306a\u304b\u306a\u304b\u81ea\u5b85\u3067\u306f\u697d\u3057\u3081\u305a\u3002
\n\u9ad8\u3044\u5468\u6ce2\u6570\u306b\u79fb\u884c\u3059\u3079\u304d\u306a\u306e\u304b\u306a\u3068\u8003\u3048\u3066\u3044\u305f\u308a\u3057\u3066\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

\u5148\u305a\u306f\u30ea\u30cb\u30a2\u30c6\u30af\u30ce\u30ed\u30b8\u30fc\u69d8\u306e\u8cc7\u6599\u3088\u308a \u3053\u306e\u8cc7\u6599\u304b\u3089\u4e00\u90e8\u629c\u7c8b\u3055\u305b\u3066\u3044\u305f\u3060\u304d\u307e\u3057\u305f\u3002 50\u03a9\u3067\u306f0dBm=223.8mV\u3002S\u30e1\u30fc\u30bf\u30fc\u306eS9\u306f50\u03bcV\u3089\u3057\u3044\u3002 Gv=20log(223.8\/0.050)=73dBm dB\u03bc\u3068\u306e…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"image","meta":{"footnotes":""},"categories":[17],"tags":[54,53],"class_list":["post-981","post","type-post","status-publish","format-image","hentry","category-ts-770","tag-dbm","tag-s","post_format-post-format-image"],"_links":{"self":[{"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=\/wp\/v2\/posts\/981","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=981"}],"version-history":[{"count":19,"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=\/wp\/v2\/posts\/981\/revisions"}],"predecessor-version":[{"id":1025,"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=\/wp\/v2\/posts\/981\/revisions\/1025"}],"wp:attachment":[{"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=981"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=981"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jg7sfr.mydns.jp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=981"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}