Building an EME station pictorial

[VK5EI]

Dean, what type of feed are you planning for your dish as that I have a similar type as well. I am slowly gathering bits and pieces and hoping to try 23cm eme one day

thanks for sharing
73
VK5EI - Joe

[VK3NFI]

Finally a long overdue update getting organised for Gippstech this year has crept up fast so that has kept
me from doing much on the dish.
As Alan VK2ZIW said the with these dish mounts the thing is designed to be fixed in one position and the locked
off never to be adjusted, and as you can see in the earlier photos all the elevation bearing consists of is a bolt
shoved through some drilled holes and then tightened up no bearing as such and this creates all sorts of wiggle and
movement not real good enough for any accuracy .
Now not being any sort of engineer the first task was to scrounge the scrap steal pile to see what I could use with out
spending more $. All I had that was really usable was some 90deg angle so the final results isn't the tidiest but its
strong with no movement.

Below is original aragment

[VK3NFI]

The bearings sourced from the local bearing supplier are a bit of overkill
but my thought is possibly for a 5m dish down the track at some point
The original mounting system didnt have enough metal to screw the bearing blocks
to, so time to polish up the welding skills.

[VK3NFI]

The photos are taken at night in the shed and the flash wasn't the best I will take some better ones soon.

[VK3NFI]

[VK3NFI]

Dean, what type of feed are you planning for your dish as that I have a similar type as well. I am slowly gathering bits and pieces and hoping to try 23cm eme one day

thanks for sharing
73
VK5EI - Joe

When I done the initial testing I was using a horizontal ring feed as to what am I going to use I simply haven't
got to that stage yet but I'm open for suggestions..

[VK2JDS]

If you are planning on EME then you will want to make up a septum. some sheet aluminium, screws, 2 N bulkheads with some copper rod or tube and the time to bend it and drill it.

have a look at http://www.ok1dfc.com/EME/Technic/septum/23-13draw.pdf

73 from Dave vk2jds

[VK3NFI]

Beginning of the H-Bridge controller with PWM drive for the motors.

[VK2OTA]

I didn't know about the the couplings with the buffer. That is a good idea.

I am still in the "Ideas" stage for making the mount. I have an ex Telstra microwave link dish built by Andrew Comminications and is a solid Aluminium that is about 4m diameter.

I am keen to see what solutions have been done, what works and traps for newbe.

One idea I have with the drive is to have 2 DC electric motors and a vehicle differential. Hooking the motors where the axels go. That way to drive slowly, you run the motors one in reverse of the other at a slightly different speed, so you have torque and a slow speed. To slew, you run both motors in the same direction and you get high speed out.

Just an idea.....




Malcolm VK2OTA

[VK2ZIW]

Conveyor belt gearboxes, I have one, 40:1 with 35mm thru shaft.
Now available on eBay, not so two years ago.
http://www.ebay.com.au/itm/Worm-Gearbox ... SwDk5Ttfha

200mm x 200mm x 100mm worm gearboxes are < $200AU from China

Zhejiang Taizhou Wangye Power Co., Ltd.
Ma’anshan, North Huangyan District,
Taizhou, Zhejiang,
318020
China
---
And with a stepper motor with 15:1 gearbox and controller to drive it, that is:
200 steps/turn x 15 x 40 => 120000 steps per turn, should be good enough resolution!!

Alan VK2ZIW