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Re: Eagle without mode S



Years ago there was so much written about Mode S being the downlink of the
future.  Now we'll have one future bird with it and one without?  I don't
understand the lack of coordination between satellite efforts but I admit I
missed the reasoning behind the design decision.

73,

John
N2HMM



----- Original Message ----- 
From: "Robert McGwier" <rwmcgwier@comcast.net>
To: "George Henry" <ka3hsw@earthlink.net>
Cc: "amsat bb" <amsat-bb@AMSAT.Org>
Sent: Monday, July 31, 2006 20:45 PM
Subject: Re: [amsat-bb] Eagle without mode S


> George:
>
> It is painful.  There is no doubt about that.  We struggled terribly.
> Let me give you one example.   We had a student in electrical
> engineering at the College of New Jersey design an S band amplifier in
> hopes it would be used on the spacecraft for a downlink.   He did a
> tremendous job under the guidance of Marc Franco, N2UO and Al Katz,
> K2UYH.  He entered a contest for "best power added efficiency".  It was
> judged by an amplifier "star",  Steve Cripes.   Steve and his committee
> gave our student,  Steve Hendricks,  received an honorable mention.
> This is because he submitted at 2401 MHz for us and all of the other
> participants did their amplifiers at 1.001 GHz in an attempt to win.
> His amplifier did extremely well and came very close to a "winner"
> slot.   I have to go tell this student that we cannot use the work he
> did for us for a year.
>
> When faced with the evidence we have,  it would simply be irresponsible
> of us to make another decision.
>
> Phase 3E,  which will go up before us if all goes as planned,  will have
> S band downlink as well as V band downlink.  We will get to test the
> rise in noise temperature all over the place and make actual measurements.
>
> Best 73's
> Bob
> N4HY
>
>
> George Henry wrote:
> > It's particularly disappointing when some of us have donated hundreds,
> > or even thousands of dollars to the project based, in part, on the
> > proposed frequencies for the various up- and  downlinks and the
> > corresponding equipment we have invested in.  Kinda feels like "bait
> > and switch" at this point, but I DO understand the technical reasoning
> > behind the decision. Probably only a relatively small percentage of us
> > would be able to get a usable downlink signal thanks to the various
> > 2.4 GHz QRM sources.
> >
> > George, KA3HSW
> >
> > ----- Original Message ----- From: "WILLIAMS MICHAEL"
> > <k9qho6762@sbcglobal.net>
> > To: <AMSAT-bb@AMSAT.Org>
> > Sent: Monday, July 31, 2006 5:37 PM
> > Subject: [amsat-bb] Eagle
> >
> >
> >> No Eagle "S" downlink, what a disappointment.
> >>
> >>
> >>  M. Williams
> >>  K9QHO
> >>  Amsat 33589
> > ----
> > Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> > Not an AMSAT member? Join now to support the amateur satellite program!
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
>
>
> -- 
> AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
> NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
> "An expert is a man who has made all the mistakes which can be
> made in a very narrow field."  Niels Bohr
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
----
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