{"id":365,"date":"2015-08-08T15:27:00","date_gmt":"2015-08-08T15:27:00","guid":{"rendered":"http:\/\/machineryequipmentonline.com\/video-equipment\/uncategorized\/video-on-magnetic-tapeazimuth-offset\/"},"modified":"2015-08-08T15:27:00","modified_gmt":"2015-08-08T15:27:00","slug":"video-on-magnetic-tapeazimuth-offset","status":"publish","type":"post","link":"http:\/\/machineryequipmentonline.com\/video-equipment\/video-on-magnetic-tapeazimuth-offset\/","title":{"rendered":"VIDEO ON MAGNETIC TAPE:AZIMUTH OFFSET."},"content":{"rendered":"<div class=\"fpigd6a0dbd959445e\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '61e5902552e2353963d8d2f1bd1f4a8f',\n\t\t'format' : 'iframe',\n\t\t'height' : 250,\n\t\t'width' : 300,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/61e5902552e2353963d8d2f1bd1f4a8f\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.fpigd6a0dbd959445e {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.fpigd6a0dbd959445e {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.fpigd6a0dbd959445e {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.fpigd6a0dbd959445e {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.fpigd6a0dbd959445e {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<h3 align=\"justify\">AZIMUTH OFFSET<\/h3>\n<p align=\"justify\">As the diagrams of Fig. 13.3 show, in all formats the video tracks are laid directly alongside each other, with no intervening guard band. When a track is being read out during playback the adjacent tracks give rise to spurious signals in the video head, even when it is correctly \u2018tracked\u2019 and exactly centred on the wanted track. These <i>c<\/i><i>rosstalk <\/i>signals can cause patterning and interference on the reproduced picture. Since adjacent tracks are scanned by different heads (i.e. the two heads\u2019 tracks are interleaved) the problem of crosstalk can be reduced by making each video head insensitive to the tracks recorded by the other. It is done by the <i>azimuth-offset <\/i>technique. <\/p><div class=\"fagpb6a0dbd9594649\" ><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-0778475562755157\"\n     crossorigin=\"anonymous\"><\/script>\n<!-- 300x600 television-and-video -->\n<ins class=\"adsbygoogle\"\n     style=\"display:inline-block;width:300px;height:600px\"\n     data-ad-client=\"ca-pub-0778475562755157\"\n     data-ad-slot=\"6549443290\"><\/ins>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.fagpb6a0dbd9594649 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.fagpb6a0dbd9594649 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.fagpb6a0dbd9594649 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.fagpb6a0dbd9594649 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.fagpb6a0dbd9594649 {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<div class=\"wbqni6a0dbd959455b\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '0c1eb4c533eaedb7b996f49a5a4983a9',\n\t\t'format' : 'iframe',\n\t\t'height' : 300,\n\t\t'width' : 160,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/0c1eb4c533eaedb7b996f49a5a4983a9\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.wbqni6a0dbd959455b {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.wbqni6a0dbd959455b {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.wbqni6a0dbd959455b {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.wbqni6a0dbd959455b {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.wbqni6a0dbd959455b {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n\n<p align=\"justify\">Conventional (i.e. audio) tape recorders use heads whose magnetic gap is at right angles to the direction of travel of the tape; this may be regarded as \u2018normal\u2019 azimuth. If a tape recorded by a normal- azimuth head is replayed in a machine whose head-gap is not at right angles to the tape\u2019s travel the signal developed in that replay head will be very de\ufb01cient in h.f. response, and the greater the azimuth offset the more will high frequencies be attenuated; indeed a high- frequency tone on a test tape is used to set up the azimuth angle of stationary audio heads in video and audio tape machines. By cutting the gaps on the two video heads on the drum at opposite angles from normal, the magnetic patterns written into adjacent tracks will have offset azimuth characteristics as shown in Fig. 13.4: azimuth angles are generally about \u00b16\u00b0. Crosstalk will still take place at low frequencies but from 1 MHz upwards a signi\ufb01cant and increasing immunity will be manifest. As we shall shortly see, the colour, and where applicable the ATF signals, occupy the vulnerable l.f. end of the tape frequency spectrum. Special circuitry eliminates the effects of crosstalk from the colour signal, while the ATF system <i>depends <\/i>on crosstalk for its operation. Each will be examined in due course.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>AZIMUTH OFFSET As the diagrams of Fig. 13.3 show, in all formats the video tracks are laid directly alongside each other, with no intervening guard band. When a track is being read out during playback the adjacent tracks give rise to spurious signals in the video head, even when it is correctly \u2018tracked\u2019 and exactly [&hellip;]<br \/><a href=\"http:\/\/machineryequipmentonline.com\/video-equipment\/video-on-magnetic-tapeazimuth-offset\/\" class=\"more-link\" >Continue reading&#8230;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"aioseo_notices":[],"views":771,"_links":{"self":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/365"}],"collection":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/comments?post=365"}],"version-history":[{"count":0,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/365\/revisions"}],"wp:attachment":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/media?parent=365"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/categories?post=365"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/tags?post=365"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}