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Article #122Re: Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve the bandwidth issue?
From: Green Xenon [Radium]
Date: Tue, 30 Oct 2007 01:13
Date: Tue, 30 Oct 2007 01:13
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3422 bytes
Green Xenon [Radium] wrote: > Paul Martin wrote: > >> In article <ujr6i3dolk1qjon2ij5tta8aip26tff9qa@4ax.com>, >> John Evans wrote: >> >> >>> Oh dear - what about the deviation? >> >> >> >>> The rule of thumb bandwidth required for FM (Carson's Rule) says the >>> bandwidth is given by >> >> >> >>> 2x(peak deviation x highest modulating frquency). > > > What is peak deviation measured in? Hz? > >> >>> So a system with a maximum modulating sinusoidal frequency of 15khz >>> using a deviation of 75khz needs 180khz bandwidth minimum. >> >> >> > > >>> Note a pulse would require a far greater bandwidth. > > > Require a far greater bandwidth compared to what? A sine wave of the > same frequency and amplitude? > >> >> Depends on the type of pulse. A wavelet might be about the same. >> > > Are you talking about the pulses [bauds] of QAM signals? > > Quotes from > http://www.howstuffworks.com/framed.htm?parent=modem.htm&url=http://www.physics.udel.edu/wwwusers/watson/student_projects/scen167/thosguys/index.html > : > > "The carrier signal is characterized by the number of signal intervals, > or pulses, that are transmitted per second. Each pulse is called a baud." In the original post of the "Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve the bandwidth issue?" I was describing converting the luminance signal to QAM and then broadcasting the QAM video on a ULF [300 Hz] FM carrier in which the QAM uses 1-symbol-per-second and a sufficient amounts of bits-per-symbol to represent the video. Unfortunately for me, it is not possible to do this.
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X-Google-Thread: f928c,9d8320c16fbdcf84 X-Google-Thread: 1133a5,9d8320c16fbdcf84 X-Google-Thread: 115947,9d8320c16fbdcf84 X-Google-Thread: 1118be,7e05cb8426dfb96 X-Google-Thread: ffcae,7e05cb8426dfb96 X-Google-Thread: 107cee,7e05cb8426dfb96 X-Google-Thread: f508e,9d8320c16fbdcf84 X-Google-Thread: f7d8a,9d8320c16fbdcf84 X-Google-Thread: fdad6,9d8320c16fbdcf84 X-Google-Attributes: gidf928c,gid1133a5,gid115947,gid1118be,gidffcae,gid107cee,gidf508e,gidf7d8a,gidfdad6,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news2.google.com!news2.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!nx01.iad01.newshosting.com!newshosting.com!post02.iad01!roadrunner.com!not-for-mail Date: Mon, 29 Oct 2007 17:13:46 -0800 From: "Green Xenon [Radium]" <glucegen1@excite.com> User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.8b) Gecko/20050217 MIME-Version: 1.0 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? References: <46fc71d2$0$24285$4c368faf@roadrunner.com> <u9hus4-6vi.ln1@radagast.org> <4722f832$0$25703$4c368faf@roadrunner.com> <ujr6i3dolk1qjon2ij5tta8aip26tff9qa@4ax.com> <slrnfi6tb4.n9a.pm@thinkpad.nowster.org.uk> <4723dde6$0$19659$4c368faf@roadrunner.com> In-Reply-To: <4723dde6$0$19659$4c368faf@roadrunner.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Lines: 56 Message-ID: <472682af$0$25653$4c368faf@roadrunner.com> Organization: Road Runner High Speed Online http://www.rr.com X-Complaints-To: abuse@rr.com