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Re: Primestar dishes



Now why are we not asking Primestar that we can take these off of their
hands ..... we might even be able to give them the tax write-off (depending
on quantity)

GB
----- Original Message -----
From: Bill Jones <wejones@megalink.net>
To: <amsat-bb@AMSAT.Org>
Sent: Friday, December 10, 1999 11:50 AM
Subject: RE: [amsat-bb] Primestar dishes


>
> > Since the Primestar system used a domestic Ku band satellite in the FSS
> > service, the dish as it stands has a feed built for linear polarization
and
> > a minimum bandwidth of 11.7 Ghz to 12.2 Ghz.  My guess is that it will
> > probably work pretty good down to high end of 10 Ghz. Unfortunately, the
> > LNB and feed are probably integrated to form an LNBF, meaning that you
just
> > cant remove the LNB. It may be possible to modify the LNBF for amature
> > frequencies.
>
> There may be more than one version of the Primestar systems, but the one I
picked up in
> the dump seems to have an LNB that will come off the feedhorn part,
however it is not a
> standard lnb with rectangular flange, but instead a cylindrical one.  I
haven't taken it
> apart yet, but I did try it out on regular KU sats to make sure it worked.
Of course,
> the output  of the lnbf for the 11700-12200 is down at 950-1450, ie
LO=10750, so it isn't
> clear to me that perhaps it might work better at the low end of the band
since the
> difference frequencies are closer to that at which the IF amps are
optimized at.  Ie
> because of the LO freq I wouldn't expect it to work at all up near that
freq, but it
> might work when you got further away from the LO.
>
> > There is no reason the Primestar antennas will not work on S band,
provided
> > an appropriate feed can be worked out. Two things are going to make that
a
> > little difficult. The first is that the antenna is elliptical, so the
feed
> > needs to have an asymetric illumination pattern.
>
> Again, I think there must be two types of Primestar dishes out there.
While the one I
> have indeed has an offset feed, the dish itself seems to be circular, ie a
regular
> parabolic shape. Ie it could be used with the Primestar feed, which has an
eliptical
> opening, or with a circular feed at the prime focus.  I have seen other
Primestar dishes
> that have non-circular dishes, which also probably have a different LNBF.
>    In any event, these things are showing up in the trash all over the
country, and at a
> minimum they can be used to pick up conventional KU TVRO  since you can
pick up TVRO
> receivers very cheaply now too. Seems a shame for them to go to waste.
>
>
>
>
>
> ************************************
> *    Bill Jones   Sweden Maine     *
> * wejones@megalink.net             *
> * http://www.megalink.net/~wejones *
> ************************************
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