Rusting satellite dish
No reception problems , even in heavy rain, but presumably will do some
time. If the dish completely rusts over , so no longer smooth, but not actually pitted with holes or distorted, would there bound to be received signal loss associated with rust rather than paint? What sort of paint over the front surface , when the rust is cleaned back ? If actual rust holes , from thinned metal that does not survive rust cleaning, then how to deal with that.? |
Rusting satellite dish
"N_Cook" wrote in message ... No reception problems , even in heavy rain, but presumably will do some time. If the dish completely rusts over , so no longer smooth, but not actually pitted with holes or distorted, would there bound to be received signal loss associated with rust rather than paint? What sort of paint over the front surface , when the rust is cleaned back ? If actual rust holes , from thinned metal that does not survive rust cleaning, then how to deal with that.? The dish needs to be smooth or there will be some loss. If already rusted, you should get a new dish. That is assuming you are using one of the small units for Direct tv or Dish. The very high wavelength needs a smoother surface than the older 10 foot size dishes. The paint should be of the type that does not have conductive particals in it. |
Rusting satellite dish
On Fri, 25 Mar 2016 12:35:51 +0000, N_Cook wrote:
No reception problems , even in heavy rain, but presumably will do some time. Most of the 0.6m DBS reception problems I've seen are the result of bad or unstable dish aiming. However, if you experience fades and dropouts, the easiest fix is to just buy a bigger dish. Mine is 1.0m diameter: http://802.11junk.com/jeffl/pics/DBS/slides/101b.html If the dish completely rusts over , so no longer smooth, but not actually pitted with holes or distorted, would there bound to be received signal loss associated with rust rather than paint? Yes. Ferrite (iron oxide) is an RF absorber. If you want to turn your dish into a radar invisible stealth aircraft simulation, just let it rust a little. To be fair, the layer of rust has to be fairly thick in order to have an effect, so you might be able to get away with it. What sort of paint over the front surface , when the rust is cleaned back ? Paint that contains no carbon, graphite, iron oxide, or any other additive that might be considered an RF absorber. Or, you could just let your imagination run wild: https://www.google.com/search?q=paint+satellite+dish&tbm=isch If actual rust holes , from thinned metal that does not survive rust cleaning, then how to deal with that.? I'm all for repairing things, even if they're not worthy of the effort. I would use automotive body putty to fill the hole, and a piece of aluminum foil to replace the missing part of the reflector. Getting the foil to simulate a parabolic shape will be difficult, but not impossible. I suggest a wooden form. Also, note that the color and surface finish of the dish is rather important. The common gray color is designed to both reflect and absorb a minimum amount of heat from the sun. If the dish were a mirror finish, when the sun goes behind the satellite belt twice each year, the reflected light would burn up the LNB. I've had it happen on larger dishes. If the dish were painted flat black, it would absorb enough heat to distort and temporarily loose shape. I don't know how Dish Networks gets away with black reflectors. The surface finish is a compromise between smooth for maximum gain, and matt for minimum light reflection. Whatever you do, don't paint it with glossy paint or you will cook the LNB. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Rusting satellite dish
Ralph Mowery wrote:
"N_Cook" wrote: If actual rust holes, from thinned metal that does not survive rust cleaning, then how to deal with that.? Is it a solid dish or a mesh one? I don't think I'd be bothered to repair a dish unless it's something special, buy a new one for £20-30. assuming you are using one of the small units for Direct tv or Dish. From the email address, I'd say it's more likely for Astra 28.2E satellites. |
Rusting satellite dish
On Friday, March 25, 2016 at 12:00:00 PM UTC-4, Jeff Liebermann wrote:
Also, note that the color and surface finish of the dish is rather important. The common gray color is designed to both reflect and absorb a minimum amount of heat from the sun. If the dish were a mirror finish, when the sun goes behind the satellite belt twice each year, the reflected light would burn up the LNB. I've had it happen on larger dishes. If the dish were painted flat black, it would Hmm. OT maybe, but........ a little bit ago we needed to measure a large number of throws of Frisbee golf discs. I had one of those big reflective round traffic signs, about the size of a good size satellite disc. It was a No Entry One Way (but the international symbol, not words). That thing really reflects, my little LED headlamp will light it up two blocks away. The back of it is just gray sheet metal but the front, wow, that reflective paint is great stuff. So the plan was have the kids throw from where the sign was set up, then go to where each disc lands and shoot back to the sign with my laser range finder. Surprise. The range finder won't read off a reflective sign at all, at any distance. Turned the sign around and it read fine off the unpainted back. I hadn't expected that. |
Rusting satellite dish
On Friday, March 25, 2016 at 5:35:51 AM UTC-7, N_Cook wrote:
No reception problems , even in heavy rain, but presumably will do some time. If the dish completely rusts over ... Oh, there's a solution for that, from the world of architecture. Plant ivy. Seriously, there's very little effect unless the dish changes shape; the Arecibo telescope doesn't look like a shiny-new dish, and it focuses radio just fine. And a thin layer of paint won't keep the underlying metal from blocking the passage of radio waves, so it'll still reflect if you decide to apply some finish. |
Rusting satellite dish
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Rusting satellite dish
Andy Burns wrote:
Ralph Mowery wrote: "N_Cook" wrote: If actual rust holes, from thinned metal that does not survive rust cleaning, then how to deal with that.? Is it a solid dish or a mesh one? I don't think I'd be bothered to repair a dish unless it's something special, buy a new one for £20-30. Or pick up an unwanted used one via freecycle or craigslist. |
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