Does anyone have suggestions on alternative surface materials to recover an old 5m C Band dish ?
The old surface, expanded AL mesh is in poor shape but replacement AL mesh is ridiculously expensive and not easy to procure is useful sizes.
Has anyone tried galvanised 'vermin mesh', 6.35mm sq holes, 0.6mm wires. Its heavier than AL mesh and probably only good to 5GHz ?
Oh, I need a surface to cover 1.2GHz thru to 10Ghz.
Surprisingly solid AL sheet, 1.00mm thick, is one of the cheapest. Might do that if anyone else doesn't have a better idea...
opinions ?
cheers,
Geoff vk2ul
Alternative Dish materials...
Re: Alternative Dish materials...
some sort of plastic and metal coat it ? , there has to be a paint surely ?
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Re: Alternative Dish materials...
Gal wire might rust out fairly quickly if it's in contact with Aluminium.
And ~6 mm holes may be too big for 10 GHz.
Bunnings sell Aluminium flywire.
Regards,
Dave
VK3HZ
And ~6 mm holes may be too big for 10 GHz.
Bunnings sell Aluminium flywire.
Regards,
Dave
VK3HZ
Re: Alternative Dish materials...
Geoff,
If you need an alternative to 1mm thick aluminium sheet, you might consider using used aluminium offset printing plates. These are available from printing companies specialising in offset printing. From memory, they measure around 745mm by 605mm and are very thin, perhaps 0.1mm or even 0.05mm. In fact, they are so thin you can cut them to shape with a pair of ordinary scissors.
I would think they could be pop rivetted together and the joins then protected with a smear of silicone to keep the weather and corrosion out.
Once they are used by offset printers, they are usually dumped into bins for metal recycling. I'm sure you could do a deal and buy them for the price that the printers get from the scrap metal companies.
Rgds es 73, de Jim VK3OX
If you need an alternative to 1mm thick aluminium sheet, you might consider using used aluminium offset printing plates. These are available from printing companies specialising in offset printing. From memory, they measure around 745mm by 605mm and are very thin, perhaps 0.1mm or even 0.05mm. In fact, they are so thin you can cut them to shape with a pair of ordinary scissors.
I would think they could be pop rivetted together and the joins then protected with a smear of silicone to keep the weather and corrosion out.
Once they are used by offset printers, they are usually dumped into bins for metal recycling. I'm sure you could do a deal and buy them for the price that the printers get from the scrap metal companies.
Rgds es 73, de Jim VK3OX
Re: Alternative Dish materials...
I live inland, 300km from the east coast, no sea air, no cities and humidity is generally lower so rust is far less of an issue. But you're right galvanic corrosion might be ? Yep, 6mm holes is only 1/5 lambda at 10Ghz, a bit too wide.VK3HZ wrote:Gal wire might rust out fairly quickly if it's in contact with Aluminium.
And ~6 mm holes may be too big for 10 GHz.
Bunnings sell Aluminium flywire.
Regards,
Dave
VK3HZ
I previously checked out Aluminium flywire and even the heaviest stuff at Bunnings is too 'floppy' for a dish this size. Not sure its tough enough over 900mm spans, would be good for a grid pack dish
thanks anyway...
VK3OX wrote:Geoff,
If you need an alternative to 1mm thick aluminium sheet, you might consider using used aluminium offset printing plates. These are available from printing companies specialising in offset printing. From memory, they measure around 745mm by 605mm and are very thin, perhaps 0.1mm or even 0.05mm. In fact, they are so thin you can cut them to shape with a pair of ordinary scissors.
I would think they could be pop rivetted together and the joins then protected with a smear of silicone to keep the weather and corrosion out.
Once they are used by offset printers, they are usually dumped into bins for metal recycling. I'm sure you could do a deal and buy them for the price that the printers get from the scrap metal companies.
Rgds es 73, de Jim VK3OX
Jim, 0.1mm might not survive a hailstorm ? Interesting idea, thanks..
cheers,
Geoff
Re: Alternative Dish materials...
All,
Found some heavier Aluminium Flyscreen at Bunnings, "Tuff Lite" by Cyclone. Its not as cheap but will do the job.
thanks all who helped...
cheers,
Geoff
Found some heavier Aluminium Flyscreen at Bunnings, "Tuff Lite" by Cyclone. Its not as cheap but will do the job.
thanks all who helped...
cheers,
Geoff
Re: Alternative Dish materials...
If your dish has the same mount as Dave VK2JDS's 5m, the Elevation hinge joint
is very poor in design, being only 90mm wide and with 1mm slop in the shaft, a bolt.
In Satellite service, everything is bolted tight.
In Ham service, it is constantly being moved, so must be loose.
Alan VK2ZIW
is very poor in design, being only 90mm wide and with 1mm slop in the shaft, a bolt.
In Satellite service, everything is bolted tight.
In Ham service, it is constantly being moved, so must be loose.
Alan VK2ZIW
Re: Alternative Dish materials...
Although this dish's elevation pivot is more substantial it does have slop. It was steered by screw-jacks in it previous life, there was some wear and round holes became ovalsVK2ZIW wrote:If your dish has the same mount as Dave VK2JDS's 5m, the Elevation hinge joint
is very poor in design, being only 90mm wide and with 1mm slop in the shaft, a bolt.
In Satellite service, everything is bolted tight.
In Ham service, it is constantly being moved, so must be loose.
Alan VK2ZIW
I've already cut the previous mount up, back to not much more than a simple support ring then, I'll weld/machine up an entirely new elevation bearing arrangement.
At the end of the day not much of this dish will be original
cheers,
Geoff
Re: Alternative Dish materials...
VK2ZIW wrote:If your dish has the same mount as Dave VK2JDS's 5m, the Elevation hinge joint
is very poor in design, being only 90mm wide and with 1mm slop in the shaft, a bolt.
In Satellite service, everything is bolted tight.
In Ham service, it is constantly being moved, so must be loose.
Alan VK2ZIW
My Idea's on fixing the sloppy bolt mounting, Might be of some interest.
http://www.vklogger.com/forum/viewtopic ... 6&start=20
Cheers .
73's
Dean VK3NFI
Dean VK3NFI