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Re: AO-40 and future sats.



Would the Ammonia Arc Jets be enough for the geosync adjustments?
The other possibility is to allow the sat to start to wobble.. I
remember when I was playing with GOES satellites back when they
were still using the older sats it only was mildly annoying to
compensate for wobble..(I added a second screw jack to my dish for
a little +/- elevation off the polar axis)

Fred W0FMS


>From: "John Stephensen, KD6OZH" <kd6ozh@gte.net>
>Reply-To: "John Stephensen, KD6OZH" <kd6ozh@AMSAT.Org>
>To: "Frederick M. Spinner" <fspinner@hotmail.com>, <amsat-bb@AMSAT.Org>
>Subject: Re: [amsat-bb] AO-40 and future sats.
>Date: Mon, 18 Dec 2000 04:28:53 -0000
>
>Each satellite needs large enough solar panels to power the transmitter. 
>You
>are correct that a microwave-only satellite would be lighter and cheaper as
>the transmitter power output required would be lower. Background noise at
>2400 MHz is 250 times lower than at 144 MHz if your antenna is pointing at
>the sky. A digital downlink would also reduce power requirements.
>
>However, the need to constantly adjust the orbit to make it stay 
>synchronous
>increases the cost and complexity beyond that of AO-40. LEOs are cheap
>because they reduce the transmitter power required for the downlink by a
>factor of 100 and eliminate the need for a heavy rocket engine and fuel.
>
>73,
>
>John
>KD6OZH
>
>----- Original Message -----
>From: "Frederick M. Spinner" <fspinner@hotmail.com>
>To: <amsat-bb@AMSAT.Org>
>Sent: Monday, 18 December 2000 02:35 UTC
>Subject: [amsat-bb] AO-40 and future sats.
>
>
> > Even if AO-40 doesn't come back-- I've done enough experimenting and
> > tinkering with my station and microwave equipment to be happy.
> > I guess thats why I am not much of a DXer.. I derive my joy in ham radio
> > from building the station up.
> >
> > Anyway.. I have and probably will still disagree with the sat community
> > about geosync sats.  If there were a way to put up three small microwave
> > sats, and maybe have two or three ground stations cross link all of them
> > together, we would have the ultimate setup.. worldwide coverage-- small
> > antennas-- no rotors.  The southern hemisphere would not get shafted
>either
> > in that scenario.
> >
> > Is it possible to put three small sats in a high orbit with a propultion
> > system, and keep it light enough to be a cheap launch?
> > I dunno-- maybe one of the aerospace guys can prove that I'm an idiot.
> > But from a communications perspective it seems like a good idea.
> >
> > I'd not completely panic yet.. Remember what was done to DO-17 and
> > KO-23.. sometimes the herculean efforts of the ground stations can
> > pay off.  I seem to remember that one of the big EME arrays recovered
>DO-17
> > once.
> >
> > My only concern really is will the batteries hold out until 21 DEC or
> > 25 DEC?
> >
> > Fred W0FMS
>
>

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