[amsat-bb] Space Center Abandoned Dish Rehabilitation - Outreach #1

Thu Aug 15 01:45:51 UTC 2019

EME seems most practical...

>From the shadows, it looks like it is on the north side of the building
and has SERIOUS blockage to the east and west through south maybe as high
as 40 degrees or more.  Then trees block the North and NE.  About the only
sky it can see is NW?

Since LEO's spend 70% of their time in view below about 22 degrees, My
guess is that this dish could only see about 10% of all possible pass
times?

But EME is high most of the time.  And easy to schedule around times of
high passes for a club station at a museum.  Also would be a high interest
item and things MOVE SLOWLY!

If it is rusted frozen, then the EASY way out is to point it roughly south
some how.  And then wait for the moon to pass through its field of view.
Hummh, lets say using the 2m feed the beamwidth is 5 degrees and the moon
goes 180 degrees in 12 hours.  Then its in view  (3dB) maybe 20 minutes at
a time?

Then to improve the number of days, one could add another dipole above and
below the existing one and then pick up additional passes without having
to move the dish.  Or easier, just nutate the feed up and down.  Then you
could get a moon pass every day.

You could predict and post a schedule of when people could make contacts.?

Just playing with ideas...

Zooming in with google earth in 3d you can stand ANYWHERE and almost see
the same views as the excellent ones alrady posted.  But walk around and
fine tune them.  Amazing...

Bob, WB4APR

-----Original Message-----
From: AMSAT-BB <amsat-bb-bounces at amsat.org> On Behalf Of John Kludt via
AMSAT-BB
Sent: Wednesday, August 14, 2019 9:25 PM
To: Michelle Thompson <mountain.michelle at gmail.com>
Cc: AMSAT BB <amsat-bb at amsat.org>
Subject: Re: [amsat-bb] Space Center Abandoned Dish Rehabilitation -
Outreach #1

Michelle,

So help me understand - what is the problem we are trying to solve?  Let's
play this out, we somehow get our hands on a  surplus dish and we fix it
up.  I will skip over the part of the story that deals with annual
maintenance costs and ongoing operational costs every time we fire it up
and use it.  The question is, use it for what?  A dish for the sake of
saying, "Heh, we own a dish" - who ever "we' is  - just does not make any
sense.

I suppose we could use it as part of a network of stations on 2.4 MHz for
HamTV but that works only if the dish is part of a greater US HamTV
network
that does not exist right now.   And it only works if the Az/El system
turning the dish is a fast enough to keep up with a LEO such as the ISS -
that is simple question of fact that we can discover.    Other uses that
would benefit the general amateur radio satellite  community?

While it is a cool idea at least to me it feels a bit like a solution in
search of a problem.  Not saying it is bad idea but I am saying so help us
understand why we need a 20 foot dish owned by the amateur *satellite*
community at large.  The other part of me that does EME sees lots of uses
but that is very different game - see HB9Q.  And before we get too far
down the road, I'd like to see not just acquisition and repair costs but
ongoing maintenance and operations costs.

Respectfully,

John

On Wed, Aug 14, 2019 at 5:12 PM Michelle Thompson via AMSAT-BB <
amsat-bb at amsat.org> wrote:

> A group of GNU Radio community members has permission to evaluate a
> dish installation in Huntsville, AL near the Space Center. If you've
> ever been to the Space Center (where the Saturn V is suspended from
> the ceiling) then this dish is right outside the main entrance. Anyone
> attending Symposium last year should recognize it!
>
> Here's a set of photos:
>
>
> https://drive.google.com/drive/u/0/folders/1d_Oi3hrIi49JxmaoNuUA-pvUXO
> s7vSz1
>
> We're looking for technical information, identification of what you
> recognize in the photos, recommended next steps, and what to watch out
> for, prioritize, or avoid. We already know we want to take the paint
> off all the ID plates and see what's under there.
>
> We want to see if we can get this working for *amateur radio operators
> to access over the internet*, ideally with a GNU Radio flowgraph to
> control it from an SDR. Our priority is to make this work for amateur
satellite.
>
> This type of setup is similar to what GNU Radio Foundation is working
> on with the Allen Telescope Array. We have the go-ahead from the Space
> Center curator to do this study and make recommendations.
>
> I have fully restored several basket-case British sports cars and then
> successfully raced them. My other team members have restored things
> even more challenging. We are not dumb, naive, or easily deterred. We
> know this may turn out to be something that requires way more work
> than we can do in any time frame we can manage. Documenting that is
> still of great value, and that is why we are asking for your help.
> Right now, no one knows much of anything about it. This sort of
> installation, if available for amateur radio, is well worth the effort.
>
> Some of the people involved have been driving past this installation
> for 20 years and want to see it back in service at whatever level we can
achieve.
> It will be discussed at GNU Radio Conference, and everyone at the
> conference will have the opportunity to see it up close and in person,
> since it's literally across the parking lot from the venue.
>
> Want to attend or find out more about GRCon?
> https://www.gnuradio.org/grcon/grcon19/
>
> If you know of someone off-list that might know details that will
> help, then please pass this along!
>
> -Michelle W5NYV + Corps of Operation Flashlight
> _______________________________________________
> 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!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
_______________________________________________
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!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb