[eagle] Re: what is going on?, some technical content at last.

Bob McGwier rwmcgwier at gmail.com
Thu Jul 10 20:56:52 PDT 2008

We have only one way forward for Eagle or the Intelsat opportunities and
that is raise money.  The days where we had our engineering cowboy and
cowgirl friends doing engineering experiments for rocket manufacturers or
space programs and were willing to sign us up to ride on experimental
launches for "free" are gone, long gone.  We signed on to those launches
without equipment in hand, built, etc.  Those days are over. So we have a
serious chicken and egg problem.  We need to be credible to raise the money.
What was being attempted and ended in personal disaster, and I hope will be
again soon with new management (meaning my replacement and NOTHING MORE),
is a design and build out of equipment that "will prove the point".


There is an alternative to think about.  I would not wait forever for the
larger picture to come together, for the good of AMSAT and amateur radio. A
likelihood assessment needs to be made regularly about the "Vision Thing"
and the will power to change directions should be found if it needs to be
done.  We could put together a small, simple package and smaller than
desirable antennas and give our users analog transponders on an Intelsat
platform.   This would require large antennas on the ground and would serve
to make our current user base quite happy I am sure.   If we do this,  it
should be the absolute dumbest, most bullet proof, impossible to destroy,
dumber than rock, transponder without a single chance of failing in 300
years unless the rocket blows up or it is hit by a meteor.  It would be a
box with two connectors and a power plug going to the smallest possible
CREDIBLE antennas.  There has been an argument that this is very undesirable
for the long term health of AMSAT, Inc.  I made the argument in the open and
have suffered regular personal threats as a result since from one very angry
disgruntled member.  I am sure it was the manner in which I presented the
argument that caused the reaction so I am 99% to blame.

But this is clearly outside of the vision statement of AMSAT, but it would
be a way forward.  If we come in with very low mass, with little footprint
and 50-100 w peak power requirements,  and we look at the matrix of costs
Intelsat gave us,  I think we might be able to raise that amount from
"amateur radio sources".


For the bigger payload and more complex vision, ACP driven, we will need
10-20 times that much money.  I will be the first to admit that I have been
utterly daunted until about 12 months ago, trying to decide what to do, how
it might be accomplished.  Intelsat came first, and then a way we could to
try and get the attention and then respect of FEMA/DHS soon followed. All of
the personal work I did to find a way forward had absolutely nothing to do
with engineering.  It was playing bureaucratic games and finding "low
friends in high places" work.  Very unsatisfying personally but I could not
see any other way forward.  

Anyway, both are ways to go. Our new leaders will decide.  Either choice
will be maddening to others should AMSAT choose it.  The new AMSAT board in
October and the officers they choose will have a hill or two to climb to say
the least.  I think they need to be given the best possible opportunity to
make choices and that entails doing some technical work, taking the work
done by the ground station team (NAMASTE) and having a discussion on how to


The interpersonal issues are over with for me.  I have removed myself from
the path of destruction and as an element in a hypergolic mixture in the
weak motor housing called AMSAT.   Michelle has given me very good advice:
get out of management and do technical work.  We have settled the argument
and I got in the last words:  YES MAAM.  I completely agree with her so the
argument is over with for me. Other arguments will be done without me.

--- technical ---

GnuRadio, the software system, not to be confused with the USRP hardware,
has a system in it call gr-pager.  It uses a polyphase filter bank to
channelize pager bands and then simultaneously demodulate the pager bursts
when received.  I have been adding the correct filter computations (the same
ones I promised Matt and Eric some time ago ..... sigh) in my fbpoly branch.
It is a pretty simple matter to take the signal front end and turn it into
gr-acp-rx.  The bpsk, qpsk demodulators are there.  I am unsure about M-FSK,
but it is simple to write and so gr-acp-tx should also be simple to write.
With a simple prototype waveform (source coding, channel coding, packet
structure, etc.) for each, we could have a live demo very quickly.    Rick
has been setting up subversion servers for multiple purposes on his servers.
I thought I would put together a 2m-70cm subset of the ACP system, running
at slower rates on the downlink and with fewer channels but have it ready to
show at Atlanta.

Matt was kind enough to modify his 70cm RF board to do 70cm and in parallel.
I do not think this will be even a lot of work to do and we can see a
tangible result with this.  16-32 channels of uplink and map to TDM for the
downlink should be achievable.

I will put code on the AMSAT subversion server.  I would put it on GR but I
don't want to argue about having to put FSF where AMSAT, Inc will need to go
in the copyright.  I am not suggesting that we follow this path.  I am
suggesting that it is a personal choice for me to do it.  If it is useful to
AMSAT, good.  If not, I hope it will be a generator of ideas.


ARRL SDR Working Group Chair
Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats,
"Trample the slow ....  Hurdle the dead"

-----Original Message-----
From: eagle-bounces at amsat.org [mailto:eagle-bounces at amsat.org] On Behalf Of
John B. Stephensen
Sent: Wednesday, July 09, 2008 6:46 PM
To: Bill Ress; David Goncalves
Cc: eagle at amsat.org
Subject: [eagle] Re: what is going on?

I'd guess that the inter-personal issues can be resolved in a few weeks. 
Launch funding is the main issue and not just for AMSAT-NA. At Ham Radio 
2008 the P3E update included the statement that "the cost quoted by 
Arianespace for the launch of P3E is outside the budget of AMSAT-DL."



More information about the Eagle mailing list