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Re: Re: Discovery Project: Which Mission Next?

"Schaik, A. van" wrote:

> > -----Oorspronkelijk bericht-----
> > Van: tlang@freeway.apana.org.au [mailto:tlang@freeway.apana.org.au]
> > Verzonden: vrijdag 1 september 2000 17:08
> > Aan: amsat-bb@AMSAT.Org
> > Onderwerp: Re: [amsat-bb] Re: Discovery Project: Which Mission Next?
> >
> >
> >
> > Hello Jon!
> >
> > Jon wrote on 31 Aug 00 at 13:47
> >
> >  JO> Enlighten me.  Why don't we have a Fast Scan ATV satellite?  That
> >  JO> would be cool!  Much more interesting than talking to
> > the same old
> >  JO> farts in one's local area.  Too much bandwidth?  Power
> > requirements
> >  JO> too severe?  Inquiring minds want to know!

Then Tone - VK3JED answered:

> > Analogue ATV?  Anyone got a satellite band 7 MHz wide and a
> > good power budget?
> > FM would need even more bandwidth. I suspect this is the main
> > problem.  Digital
> > technology should help to create useful ATV birds, by
> > allowing narrower
> > bandwidths.
> >
> > Would love to beam TV pictures around, but we may have to be
> > creative to get it
> > working within amateur constraints. :-)

Then Andre - PE1RDW said:

> We have one digital tv transponder linked to a ATV repeater in the
> netherlands.
> I think it was on hotbird with a wide beam, it might be usable on the east
> coast with a large dish.
> It's all part of a sponserschip deal (the repeater is located at a satalite
> shop) so if one repeater can do it so can others.

And now Jim (me) - K6CCC replied:

I'm assuming you are refering to taking the downlink from a commercial
satellite and repeating that downlink onto an ATV repeater.  That is commonly
done with NASA-TV off GE2 during space shuttle missions.  This is specifically
allowed in the FCC rules (normally it's illegal in the US to retransmit another
radio service).
I believe the original discussion was transmitting fast scan ATV via an amateur
satellite.  For that we don't have anywhere near enough bandwidth available on
all amateur satelllites that have ever been launched combined.  AM/VSB takes
close to 6MHz, narrow band FM is close to 17 MHz and wideband FM is about 36
MHz wide.

Jim Walls - K6CCC
626-302-8515    FAX  626-302-9999
AMSAT member 32537 / WSWSS member 395

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