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

[Rick Hambly (W2GPS)]

Bill,

Your premise that there is no L-band is incorrect and based on fragments of
comments, not the whole story.  The Eagle satellite is still undergoing
design review but I suspect you will fine L-band to be active in the final
design.  If you want to be part of the discussions, join the Eagle project
team and contribute your time and energy to the satellite design as many
others are doing. That, and not amsat-bb is where the serious technical
discussions are taking place.

Rick
W2GPS
AMSAT LM2232
 

-----Original Message-----
From: Bill Ress [mailto:bill at hsmicrowave.com] 
Sent: Wednesday, September 20, 2006 1:15 PM
To: Rick Hambly (W2GPS); sco at sco-inc.com
Cc: amsat-bb at amsat.org
Subject: RE: [amsat-bb] Re: Why do the amsats get more and more complex?

Hi Rick,

I've been critical of the "no L-Band" decision and your recent comments
don't lessen that critique.

Your last posting said "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."

What concrete evidence is available that substantiates your claim? Perhaps
"real" data could convince me and others that the decision is based on fact
and not a paranoia about what could happen. Everything I've heard to date
from AMSAT is anecdotal, opinionated and based on what you just said - FEAR.

To the contrary, the "fact" is that Galileo's own web site states (which I
have referenced here already) the reality of having to work in an
interference environment (i.e. ground ATC radar's and harmonics from TV
transmitters just to name of few) and has already started a two year study
program to evaluate appropriate design considerations.

I have been unable to find ANY reference to any governmental agency making
plans to eliminate the L-Band Amateur allocation in view of Galileo. Do you
have evidence to the contrary?

Another "fact" is that the P3E team, rather than "abandoning" the
allocation, has an "engineering" approach to mitigate the potential for
interference by selecting a L-Band frequency which puts the signal in a
Galileo signal null (already pointed out by others here).

This debate could be put to rest if you could present us with "facts" and
not the "lets get out of the kitchen 'cause we may not be able to stand the
heat" argument I've seen so far.

Ready to be convinced...

Bill - N6GHz
AMSAT #21049

-----Original Message-----
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org]On
Behalf Of Rick Hambly (W2GPS)
Sent: Wednesday, September 20, 2006 5:55 AM
To: sco at sco-inc.com
Cc: amsat-bb at amsat.org
Subject: [amsat-bb] Re: Why do the amsats get more and more complex?


Les,

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.

Rick
W2GPS
AMSAT LM2232

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