Read about how some people have made dishes by hand out of various off the shelf products and stuff. Is there any way to do something like that to make a Primestar wider to pick up Cband better than it'll do as is?
Any way to extend a dish to make it wider?
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I don't recommend it. The angles will not come right. And the time and effort you will put into it will not outweight the cost of a new bigger dish.
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I think you'd be better off building it completely from scratch IF you want a fabrication project. The focal length of a small dish is going to be shorter than a large dish. If you simply increase the size, and out of necessity maintain the same short focal length, the efficiency of the lnb would probably decease because of the increasing curvature of the outer portion of the larger small focal length dish. And its not like you can change the focal length of the existing dish.
Simplest route has got to be finding an old C band dish.
Simplest route has got to be finding an old C band dish.
I figured that... Honestly, at the moment, we don't have the room for a CBand.
I was just was curious if it was possible since lots of folks are messing with primestars as mini-buds.
Thought it might make someone a nice side project to try fiddling with in spare time.
I here some folks (IAFIRE) have a few spare Primestars and are looking for things to do with them. If, big if, it was somehow possible, could you cut some primestars up and sort of use the parts to assemble something like wings to the left and right and top and bottom of one primestar, if for no other reason, than to get those weak cband signals that primestars can pick up in just a smidge stronger?
I was just was curious if it was possible since lots of folks are messing with primestars as mini-buds.
Thought it might make someone a nice side project to try fiddling with in spare time.
I here some folks (IAFIRE) have a few spare Primestars and are looking for things to do with them. If, big if, it was somehow possible, could you cut some primestars up and sort of use the parts to assemble something like wings to the left and right and top and bottom of one primestar, if for no other reason, than to get those weak cband signals that primestars can pick up in just a smidge stronger?
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I don't believe cutting up a primestar dish (how cruel) would help. The curvature of the pieces will be wrong for their new position. There is a freeware parabola calculator program available online. It lets you calculate and view a cross-section and focal distance of a dish. It might be possible to use it to calculate and build an extension onto an existing dish. If you have an oval or offset dish the construction might be quite complicated. I'm going to try to build a 36" dish using the program using scrap materials just for fun. I can give you a link to the software if you can't find it. Even if you don't use it to build something it is fun to see the correlations between focal length, diameter and depth.
Here is the one I use.............
http://www.satellite-calculations.com/
As mentioned above if you think of the LNBF as a flashlight there is no point making the dish bigger unless you move the LNBF further away from the dish to "light" up the whole dish reflector!
http://www.satellite-calculations.com/
As mentioned above if you think of the LNBF as a flashlight there is no point making the dish bigger unless you move the LNBF further away from the dish to "light" up the whole dish reflector!
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The idea of extending the dish sounds good in theory, but is impractical and almost impossible to acheive. Generation of a parabolic surface is a mathmatical equation that doesn't allow it to be extended in this manner. Errors in fabrication of the petals, attached to the perimiter of the dish, would cause the reflected microwaves to arrive at the focal point out of phase with similar waves reflected by the original portion of the dish. As the new reflected microwaves become 180 degrees out of phase, their energy would subtract from the properly focused microwaves. Microwaves reflected by a true and accurate parabolic surface all reach the focal point in phase with eachother, while microwaves reflected by anyother curve arrive at the focal point in varing degrees of phase. Overall effenciency of the larger dish would be reduced to the point that it would actually function as a much smaller dish than the original.
Early homebrew dishes (15 ft. x 15 Ft.) were constructed using spherical curves and had to be very large to get sparkle free reception from analog C band. The term "spherical aberration", is used to describe the out of phase condition.
Early homebrew dishes (15 ft. x 15 Ft.) were constructed using spherical curves and had to be very large to get sparkle free reception from analog C band. The term "spherical aberration", is used to describe the out of phase condition.
It all very interesting stuff. Techpuppy, that sounds like a fun project. Let us know how it goes. I had a couple of sculpture classes in college, so know a little about some stuff... Since it's all really about angles and stuff, I think someone could, in theory, find a cband dish, use it as a mold with a lot of plaster or something, and then use that to create a lost cast mold, so you could make all sorts of dishes out of plaster, or whatever other materials you wanted....
It'd be brittle if plaster was all that there was in it, but experiments like that could lead to some interesting areas down the road maybe? Coat plaster with metalic paint, hammer aluminum or other materials in to the shape needed, etc. I'm suprised dish making companies haven't tried that sort of stuff to explore what sorts of metals actually work better...
Imagine, for the super rich and stylish a satellite dish made entirely out of silver or gold... probably wouldn't work too well since it'd probably burn up the lnb with sun's reflections, but that'd be cool.... almost like something you'd see on Austin Powers Gold Member...
If I had a lot more money and room and/or a big art shed the size of a barn, I'd consider doing all that sort of stuff and setting up a sculpture show somewhere. This sort of stuff combines technology and art... really cool area to explore.
It'd be brittle if plaster was all that there was in it, but experiments like that could lead to some interesting areas down the road maybe? Coat plaster with metalic paint, hammer aluminum or other materials in to the shape needed, etc. I'm suprised dish making companies haven't tried that sort of stuff to explore what sorts of metals actually work better...
Imagine, for the super rich and stylish a satellite dish made entirely out of silver or gold... probably wouldn't work too well since it'd probably burn up the lnb with sun's reflections, but that'd be cool.... almost like something you'd see on Austin Powers Gold Member...
If I had a lot more money and room and/or a big art shed the size of a barn, I'd consider doing all that sort of stuff and setting up a sculpture show somewhere. This sort of stuff combines technology and art... really cool area to explore.
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When my father and I made a parabolic reflector for a solar oven what we did was to graph and trace onto a template the cross sectional shape of on side of the parabola. This was then duplicated onto the many petals and when they were arranged about the centre you had the parabola, minus the reflective surface. I'd Imagine you could do this with the material of your choice and cut the profile on a bandsaw.
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