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Posted by Michael A. Terrell on 09/24/07 18:59
"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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