Building an EME station pictorial

[VK3NFI]

Hi folks after getting an interest in eme I've decided to build a 23cm setup, and after hours upon hours of goggling and looking at others diagrams photos etc, there is plenty of information out there but it scattered all over the place so with that in mind I though it might be a good Idea to document as many stages of the build as I can and any input from other Amateurs out there would also be appreciated.
As this is my first attempt at doing anything like this I though I would document as I go. From setting up the transmitter to building the controller and mounting the antenna system with as much detail as I can with out going overboard
like bearing systems i am using etc. Now this is no engineering masterpiece and I am certainly no engineer but Ill have a go at most thing and try to solve the problems along the way. I have no real plan to this set up but just rather just
nutting it out as I go and see what gear I can scrounge along the way and attempt to make it work .hi hi

So first a list of gear for the setup so far
Icom IC-910h (locked)
GPS Oscillator (built from scratch will post pics)
VK5DJ Beam Control (under construction, will post pics)
3m Mesh dish (FREE BEE getting this started it all)
100/1 worm drive box (azimuth/brake)
18inch screw jack (elevation)
3m southern cross tower (very top section only)
4X4 Axle/hub (main support bearing)

Will add more as I get bits and pieces.
Also will add pics and updates as I go.

Thanks to the local guys that have helped with problem solving along the way and a big thanks to VK3WRE Ralf for the lathe and machining work.

[VK3NFI]

The beginning... for 20 years since I moved in I've been looking for an excuse to fix this broken slab....

So this is my starting point a 3 meter top from some tower I found up the scrap yard
5mm plate welded on the top yet to be reinforced.

[VK3NFI]

Bearing assembly to support all the top end gear is an old 4X4 axle hub and tube.

Above main support

Notice the wheel hub has been machined down (shiny part) so a tube can slide over the top

The stem tube or mounting pole the dish sits atop of consists of two sections

[VK3NFI]

The two sections are to get the hub stepped down to a usable size as to mount the dish hardware on.
the smaller tube steps down to 90mm OD

Notice the lathed step up collars, Thanks Ralf nice work.

[VK3NFI]

The small tubes are welded to line up with the wheel nut stud holes on the axle hub

[VK2KRR]

Looks like a good project Dean, cant wait to see how it progresses.

[VK3NFI]

Moved from other topic.

The initial Alpa phase of the elevation setup testing using an 18inch 36volt powerjack(brand) screw jack motor assembly.
The jack comes with its own internal reed switch for feedback sensing however I wont be using this system rather Ive opted for
the more accurate magnetic hall sensor (no pictures as yet)

I am a bit of hay-band and barbed wire constructor
so if you look really close you can see my chook poo welds..

These are the only videos I have posted so far http://www.youtube.com/watch?v=KzsFCPSyWfM



and http://www.youtube.com/watch?v=yJI2WktGfQo

[VK3NFI]

The dish was installed at a farm house behind Cypress trees so the mesh had moss and lots of rubbish that
needed cleaning off so out with the hand wire brush as the mesh is fairly soft so I wasn't going to risk trying
a drill and wire wheel.

Feed arms installed

Rear of feed

[VK3NFI]

Now that the dish was ready for testing it was time to find a sky-hook ......I didn't think about that
before I decided put it 5m in the air did I.. So sky hook was needed and as the dish is only about 25kg
with the feed mounted it didn't need a heavy lift crane so in comes the gin pole ( old Hills telescopic 2 sections).

Home brew gin pole

All ready for the lift now if only the wind would stop blowing .....

[VK3NFI]

Well after much groaning and few skun knuckles the dish is installed on the head
I will be installing a winch on the gin pole so it can become a one person job

Running the screw jack through it movement tests. There is no feed back sensor
installed at the moment so its just a static test, I will post a video of the the jack
movement soon as I can.

[VK3NFI]

The wormdrive gearbox is the next thing on the drawing board but in the meantime
nothing like......

Ye Olde Armstrong

West looking at VK5

Day is done I have a smile on my face time to go see what I can hear......

[VK3NFI]

After locking the armstrong off in a sotrta westerly direction I fired up the 910
and the last thing I expected to see, keeping in mind no pre-amp yet and 3 different
pieces of coax was this, from 1296.530 VK3RXX

Some nice aircraft doppler being the first thing I seen was kinda worth all the hard
work over the last few months..

[VK4GHZ]

Looking really good there, Dean.

Pictures and description are very appreciated.
It helps others see what's involved in getting things up and running.
Few make the effort to openly share info like this. Strange, because it all helps encourage more activity, so good on you.

We look forward to seeing/hearing what you can work.

[VK2KRR]

Hi Dean, looks great! well done!
Great that you heard VK3RXX and good to hear that its up and running still, but be nice to have 23cm beacon at 3RGL site also in my opinion.
The dish is also similar to mine. Its a shame your so far east of Melbourne as I would love to try some tests with you.
I know your doing this for EME, but you always seem to be in a good location for 2m WSPR toward VK5LA and other VK5's so it might be good for them to try testing with you when the conditions are good. You will find some VK5's with 23cm are VK5GF, VK5AKK, VK5ZK, VK5BC, VK5PJ, VK5LA. Bill VK5ACY is also in the process of getting running. If your running the GPS locked IC910 you could sucessfully run tests with JT65 or even WSPR for that matter.
No doubt you would probably have a good path to Mt Gambier also.

As Adam said, thanks for sharing the photos and build info etc.

Keep us posted.

[VK3NFI]

Thanks for the feed back guys I should have mentioned earlier that if you take a good look at the feed that I have on the dish at the moment
its not the feed i will be using for EME as the current feed (loaned from VK3WRE) is horizontal polarization not circular and a new feed is on
the agenda. Leigh I will be trying to work some of the VK5's soon as I get some motor control on the azimuth
more updates to come stay tuned...

[VK3NFI]

Ok now the time I've been dreading the installation of the worm reduction box.

How to mount the thing in the middle of the tower so its square and plumb.
After scratching my head and coming up with all sorts of complex ideas, I decided to
go down the steal yard and see what I could find..
Well after really having no idea what to do this is what I came up with..

C channel

Next will be bend it seam weld along the cuts and weld it to the tower legs.

[VK3NFI]

The coupling is from the local bearing supplies and cost about $50
much easier than tiring to make your own especially with the wind loading
forces this will come under.

[VK3NFI]

[VK3NFI]

The little nipple ion the end of the shaft is for the magnet on the 5045 encoder sensor.

[VK2ZIW]

Dave VK2JDS has the bigger dish, 5m and has problems with the, very poor elevation bearing.
"bearing", ballony, just a bolt through holes. It's meant to be adjusted, then bolted tight,
never to move again.
My 2.5m, yours and Dave's are the same mount as your picture.

You must, before going any further, fix this. Dave's flops all about, +- 2 deg.

Alan VK2ZIW