[amsat-bb] Re: Why do the amsats get more and more complex?

Rick Hambly (W2GPS) w2gps at cnssys.com
Wed Sep 20 05:54:50 PDT 2006


Don't forget, these issues are all under review as we speak.

The answer is in two parts. First, an L-band ground antenna would be too
large to disguise as a TVRO dish. Second, there is fear that over the
lifetime of Eagle that L-band could become unavailable, particularly in
Europe, if the Galileo system is deployed.  Galileo would be a primary
service and Ham transmissions would likely interfere with low cost
commercial receivers.

I don't wish to debate these points. I'm just telling you the reasoning that
went into not choosing L-band. I assure you that every possibility was
considered. Lists were created and discussed on each alternative.


-----Original Message-----
From: sco at sco-inc.com [mailto:sco at sco-inc.com] 
Sent: Tuesday, September 19, 2006 11:29 PM
To: Rick Hambly (W2GPS)
Cc: amsat-bb at amsat.org
Subject: Re: [amsat-bb] Re: Why do the amsats get more and more complex?

Maybe someone can explain why Eagle could not use the L Band for its 
digital uplink instead of S Band? Then you would have a L/C mode and 
many users already have a L band uplink capability.


>Eagle will carry a payload that it is hoped will revolutionize Amateur
>Satellite communications and Ham Radio as a whole.  Initially called C-C
>Rider, I will call it the Advanced Communications Package (ACP) because it
>no longer uses C-band for both uplink and downlink. This package will be
>designed to bring satellites and DX to you and to many other Hams who have
>never been able to use a satellite or operate DX before.  This is because
>the ground station antenna will be small, power levels reasonable, many
>modes will be supported (from Voice and CW to Video and data
>communications), the ground station will be affordable and the signal
>quality will be superior. Much of this is accomplished through the use of
>digital techniques so it will require all new equipment on the ground.
>will design the ground station equipment and publish everything so you can
>buy it, copy it, sell it, or build it.
>The Eagle band plan has been the subject of much discussion, of late.
>is still in the design phase and the band plan is not finalized, so don't
>worry just yet.  The confusion was the result of the ACP (C-C Rider) team
>realizing that they had to find another band for the uplink. They chose
>S-band for some good reasons but that recommendation is under review by the
>whole Eagle team and is not yet final. There should be a final announcement
>at the AMSAT Symposium in a few weeks.  I encourage everyone to come to the
>Symposium and meet your AMSAT officials and learn what is really happening
>in AMSAT.

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