[amsat-bb] Amateur communication satelliteshttps://mail.aol.com/webmail-std/en-us/suite#

[Edson W. R. Pereira]

One area that I believe would welcome more experimentation is digital
transponders and digital repeaters. I think there is a vast territory for
experimentation (protocols, ground software, etc). With some careful
engineering, a digital transponder could be operated on the same frequency
using half-duplex. This would simplify the antenna system and ease the
operation.

73, Edson PY2SDR

---
- We humans have the capability to do amazing things if we work together.
- Nós seres humanos temos a capacidade de fazer coisas incríveis se
trabalharmos juntos.

On Wed, Jun 29, 2016 at 9:28 AM, rsoifer1--- via AMSAT-BB <
amsat-bb at amsat.org> wrote:

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> Paul,
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> I didn't say that AO-7, FO-29 and SO-50 are the only communication
> satellites, only that they are the most popular and useful.
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> Why is that?  As you say, some of that has to do with altitude, which is
> largely beyond our control.  Some has to do with low power output, which
> depends on satellite size.  Some, too, has to do with operating schedule:
> is it always on?
>
> 73 Ray
> -----Original Message--- do
> From: Paul Stoetzer n8hm at arrl.net is
> To: rsoifer1 <rsoifer1 at aol.com>
> Cc: amsat-bb <amsat-bb at amsat.org
> Sent: Tue, Jun 28, 2016 1:48 pm
> Subject: Re: [amsat-bb] Amateur communication satellites
>
> Ray,
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> The CW beacon on FO-29 does still function. We are definitely
> fortunate that FO-29 still works and works very well. It is clearly
> the most popular linear transponder satellite due to it's wide
> passband and high orbit.
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> I would note that we are not starved for linear transponders. There
> are 7 in orbit and active and 4 in orbit awaiting activation plus at
> least one more scheduled for launch this year (Nayif-1). As far as FM
> satellites, there are three in orbit with two of those available 24/7
> and a third with an errattic schedule. However, between now and
> January, three more FM satellites are scheduled to launch (Fox-1Cliff,
> Fox-1D, and RadFxSat/Fox-1B).
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> The issue, of course, is the orbits of these satellite don't approach
> the 1460km apogee or 1330km apogee of FO-29. We can blame debris
> mitigation rules for that! Hopefully we will find a way to get some
> higher orbiting satellites up in the future (including GEO/HEO).
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> 73,
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> Paul, N8HM
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> On Tue, Jun 28, 2016 at 4:28 PM, rsoifer1--- via AMSAT-BB
> <amsat-bb at amsat.org> wrote:
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> > This past weekend, I made three ARRL/AMSAT Field Day QSOs via FO-29
> (JAS-2). Nothing noteworthy about that, except that FO-29 will be 20 years
> old on August 17th.  We're very fortunate that its linear transponder still
> works.  The CW beacon and digital transponders are no longer functioning.
> >
> > Two more of the satellites carrying the bulk of amateur satellite
> communication are well beyond their design lifetimes.  SO-50, our main FM
> transponder satellite, will be 14 years old in December.  Then, of course,
> there is AO-7, whose linear transponders miraculously are still functioning
> some of the time.  In November it will be 42 years young.
> >
> > Educational and research satellites are well and good, but amateur
> satellite communication is still overly dependent on aging space hardware.
> To those who are building new amateur communication transponders,
> especially linear transponders in the UHF and VHF bands, best wishes for
> success.  I wish there were more of you.  Maybe there will be.
> >
> > 73 Ray W2RS
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> > _______________________________________________
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> Opinions expressed
> > are solely those of the author, and do not reflect the official views of
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> _______________________________________________
> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
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