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

Wed Aug 14 22:34:43 UTC 2019

Robert,

Not that it is something we could fix but really like this site:

https://eyes.nasa.gov/dsn/dsn.html

It lets you real time observe what Canberra, Madrid and Goldstone are
doing.  Fascinating to watch.

I don't recall the name of the site in North Carolina that has the
rejuvenated dishes.  But a ham friend of mine took a tour and it is pretty
cool stuff.  Unfortunately they are not much used because according to them
these old dishes are very expensive to operate.  Must be kind of like
buying a horse - the real money gets spent not when you buy the horse but
over the next twenty years as you pay to maintain the trusty steed!

John

On Wed, Aug 14, 2019 at 6:22 PM Robert MacHale via AMSAT-BB <
amsat-bb at amsat.org> wrote:

> Wow! Fun project. Very exciting.
> Any chance there are also antique antennas at the California ground
> station at Goldstone. Nasa had three primary ground stations for Apollo:
> Spain, Australia, and California.
> https://www.gdscc.nasa.gov/
>
> 73
> Robert MacHale. KE6BLR Ham Radio License.
> http://spaceCommunicator.club/aprs
> . Supporting Boy Scout Merit Badges in Radio, Robotics, and Space
> Exploration
>
>
>
>     On Wednesday, August 14, 2019, 2:54:16 PM PDT, Daniel Cussen via
> AMSAT-BB <amsat-bb at amsat.org> wrote:
>
>  I would recommend trying to find out if the motors are AC or DC or some
> weird voltage or stepper or servo type. If you can get the motors to move,
> position feedback could be added with a simple potentiometer from a belt,
> or a fancy encoder. It may be possible to use the old position feedback,
> but it may be faster and easier to mount something on the outside that
> gives the same result.
>
> In terms of frequency ranges,  rate of tracking, dish beam width, these
> will determine what it could be used for, and assuming you use the old
> motors and the reflector on the dish is designed for vhf?, then this would
> limit top frequency and maximum tracking ability aligned with beam width.
> Say vhf, UHF lower microwave, and presumably the dish could track low earth
> orbit or moon bounce.
>
> Looking at the photos it looks like the right middle connector is an n type
> coax connector for the feed. I assume the military type connectors are for
> position feedback from some sort of rotary or absolute encoder. Often there
> is an encoder mounted near or on the motor, which is AC or DC simple motor.
>
> If the manual movement cranks work you could run belts to them and mount
> new motors on the outside. Speed might be limited, but acceptable.
>
> I would recommend adding hardware limit switches no matter what you do to
> ensure the dish can never rotate too far and damage itself. It may have
> limit switches inside, but they may need replacing and external switches
> would be easier to service.
>
> It would be great if this could track low earth orbit and receive school
> contacts from the iss and cubesats on vhf and UHF.
>
> I would like to see it receive 2395MHz Hamtv from the ISS, which is
> relatively strong and easy to receive.
>
>
> On Wed, 14 Aug 2019 22:11 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-pvUXOs7vSz1
> >
> > 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
> > _______________________________________________
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> _______________________________________________
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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!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>