{"id":355,"date":"2015-08-08T15:43:00","date_gmt":"2015-08-08T15:43:00","guid":{"rendered":"http:\/\/machineryequipmentonline.com\/video-equipment\/uncategorized\/videorecorder-signal-processingcolour-under-system\/"},"modified":"2015-08-08T15:43:00","modified_gmt":"2015-08-08T15:43:00","slug":"videorecorder-signal-processingcolour-under-system","status":"publish","type":"post","link":"http:\/\/machineryequipmentonline.com\/video-equipment\/videorecorder-signal-processingcolour-under-system\/","title":{"rendered":"VIDEORECORDER  SIGNAL  PROCESSING:COLOUR-UNDER SYSTEM"},"content":{"rendered":"<div class=\"vjdvc6a0dc840b1230\" ><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.vjdvc6a0dc840b1230 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.vjdvc6a0dc840b1230 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.vjdvc6a0dc840b1230 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.vjdvc6a0dc840b1230 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.vjdvc6a0dc840b1230 {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<h3 align=\"justify\"><em><u>COLOUR-UNDER SYSTEM<\/u><\/em><\/h3>\n<p align=\"justify\">The basic concept of colour-under video recording is a simple one: to translate the entire encoded chroma signal to a lower frequency around 700 kHz for recording by means of a heterodyne process with a local oscillator; and during replay to translate it back to its correct 4.43 MHz frequency by a second heterodyne process. If the tape were a perfect recording medium this would be all that were necessary. In practice there are three factors which prevent the use of such a simple system: the fact that at low colour-under frequencies the azimuth- offset of the recording heads does little to prevent inter-track crosstalk; an inability with conventional electronics to control replay speed within the very \ufb01ne limits required to adequately maintain colour subcarrier frequency during replay; and, allied to this, the mechanical imperfections in the deck, transport system and tape rib- bon which impart timing jitter to all video signals recorded and replayed on tape \u2013 or, indeed, on disc. Chapter 6 indicated how crucial is the timing and phase of the chroma signal, which must be held to within \u00b13 ns or so, representing a mere 5\u00b0 of phase error tolerance. Such a requirement is far beyond the ability of a mechanically driven system, so special arti\ufb01ces are necessary to maintain correct hue and saturation in the reproduced colours.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>COLOUR-UNDER SYSTEM The basic concept of colour-under video recording is a simple one: to translate the entire encoded chroma signal to a lower frequency around 700 kHz for recording by means of a heterodyne process with a local oscillator; and during replay to translate it back to its correct 4.43 MHz frequency by a second [&hellip;]<br \/><a href=\"http:\/\/machineryequipmentonline.com\/video-equipment\/videorecorder-signal-processingcolour-under-system\/\" 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":845,"_links":{"self":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/355"}],"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=355"}],"version-history":[{"count":0,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/355\/revisions"}],"wp:attachment":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/media?parent=355"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/categories?post=355"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/tags?post=355"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}