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Article #153Re: Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve the bandwidth issue?
From: Michael A. Terrell
Date: Mon, 24 Sep 2007 18:59
Date: Mon, 24 Sep 2007 18:59
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3350 bytes
"Brian Gregory [UK]" wrote: > > "Green Xenon [Radium]" <glucegen1@excite.com> wrote in message > news:46f6d850$0$11068$4c368faf@roadrunner.com... > > Hi: > > > > One major reason the luminance signals of television are broadcasted on an > > AM-carrier instead of FM is because FM requires large amounts of > > bandwidth. Is there a way to use FM video without hogging so much > > bandwidth? > > > > Quotes from > > http://groups.google.com/group/sci.electronics.basics/msg/0c013cf5371da8dc?hl=en& : > > > > >Multiple-level quadrature modulation, > > >"constellation modulation", > > >is most common for packing > > >lots of bits per Hz of bandwidth. > > >The more you pack, > > >the better the s/n ratio has to be. > > > > >http://en.wikipedia.org/wiki/Quadrature_amplitude_modulation > > > > >http://en.wikipedia.org/wiki/Constellation_diagram > > > > Does this mean that Quadrature Modulation and Constellation Modulation > > can -- at least in theory -- be applied to FM video so that excessive > > bandwidth is not needed? If so, then what would be the minimum > > radio-frequency required to transmit the video signal? > > No. > > These are like special modified forms of AM. > > You can only use these to reduce bandwidth of an FM signal in the same way > that you can use AM to reduce the bandwidth of an FM signal. It just won't > be FM any more. radium is a troll. he tries this crap on a lot ot different newsgroups, and asks stupid questions to entertain himself. If you don't believe me. look at his posting history on Google Groups, then kill file him. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida
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X-Google-Thread: f928c,7e05cb8426dfb96 X-Google-Thread: 1133a5,7e05cb8426dfb96 X-Google-Thread: 115947,7e05cb8426dfb96 X-Google-Thread: 1118be,7e05cb8426dfb96 X-Google-Thread: ffcae,7e05cb8426dfb96 X-Google-Thread: 107cee,7e05cb8426dfb96 X-Google-Thread: f508e,7e05cb8426dfb96 X-Google-Thread: f7d8a,7e05cb8426dfb96 X-Google-Thread: fdad6,7e05cb8426dfb96 X-Google-Attributes: gidf928c,gid1133a5,gid115947,gid1118be,gidffcae,gid107cee,gidf508e,gidf7d8a,gidfdad6,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit From: "Michael A. Terrell" <mike.terrell@earthlink.net> Newsgroups: uk.tech.digital-tv,rec.video.production,uk.media.tv.misc,sci.electronics.components,uk.tech.broadcast,sci.electronics.misc,aus.radio.broadcast,ba.broadcast,alt.radio.broadcasting Subject: Re: Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve the bandwidth issue? Date: Mon, 24 Sep 2007 14:59:37 -0400 Organization: http://home.earthlink.net/~mike.terrell/ Message-ID: <46F80919.97707803@earthlink.net> Reply-To: mike.terrell@earthlink.net X-Mailer: Mozilla 4.76 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 References: <46f6d850$0$11068$4c368faf@roadrunner.com> <6cqdnUjOUPTnQWvbnZ2dneKdnZyinZ2d@pipex.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@supernews.com Lines: 52 Path: arc1-ca.pugleaf.net!g2news2.google.com!news4.google.com!proxad.net!feeder1-2.proxad.net!feed.ac-versailles.fr!uvsq.fr!freenix!sn-xt-sjc-04!sn-xt-sjc-08!sn-post-sjc-01!supernews.com!corp.supernews.com!not-for-mail