Using an FM-Carrier for the Y [Luminance] Signal -- how to relievethe bandwidth issue?

[Green Xenon [Radium]]

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/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?


Thanks,

Radium

 

[Brian Gregory [UK]]

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& :


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.

 

[Brendan Gillatt]

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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&
:


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?


Thanks,

Radium

Okay now you're actualy irritating me quite a LOT.

Please, do yourself a favour: buy an Amazon book voucher and shut up.

- --
Brendan Gillatt
brendan {at} brendangillatt {dot} co {dot} uk
http://www.brendangillatt.co.uk
PGP Key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xBACD7433
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[Michael A. Terrell]

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