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I had made a wifi extender out of a satellite dish quite a few years ago and it worked well. Unfortunately over time it failed and since I was given a larger satellite dish I thought it was time to build a new one. One of the reasons for the failure was because it wasn't sealed properly and the wifi unit and its connections rusted.

Edited: I added a feed horn to the unit because the internal usb wifi antenna broadcasts sideways but it's pointing forward and by adding a feed horn the signal strength has at least tripled. The pictures for the feed horn are at the end of this instructable. The third picture on this page is the way the dish is now.

I also tried to turn the dish upside down which is a good thing to do but I found I lost a lot of the signals. I was just doing something wrong and since it works pretty good anyway, I left the dish upside right.

Step 1: Materials

-A satellite dish with feed horn

-active USB cable (for extending the regular usb line)

-USB wifi dongle (I bought a high power one for extended range because the regular one could receive but didn't have enough power to transmit properly)

-3 inch plastic pipe (I used leftover black ABS from a sewer project)

-1 1/2" inch plastic pipe (from same sewer project)

-1" x 4" board

-Closed cell foam (pipe wrap and for sealing cracks)

-old flowerpot

-thin sheet of metal

-metal strip

-dessicant

-zip ties

-screws

-silicone

-paint

-drill

-jigsaw

-angle grinder

-scissors

Step 2: The Feedhorn

The original feed horn was disassembled and the plastic outer cover was kept. The tube was cut off and inserted into the 1 1/2" pipe where it was almost an exact fit. Silicone was spread inside of the black tube before insertion. Once inserted, screws were used to hold it in place and then more silicone was smeared around the joint.

The mark on the tube is where the feed horn had been placed previously in its mount.

I didn't take any measurements because it is all dependent upon the length of the USB wifi unit but the large pipe should be long enough for the unit plus some extra room and the 1 1/2" pipe should be long enough for the antenna.

Step 3: The Base Cylinder

The 3" pipe was used as a guide to draw a circle on the base of an old plastic flower pot. This was a cover for the end and I cut it out with scissors. Then holes were drilled through the cover and the ends of the pipe so screws could be inserted. Then the plastic cover was used as a template for a metal disk. The plastic cover was too thin and bent when the unit was assembled but it does make a good gasket. Thicker plastic might work better if you don't want to use metal.

Step 4: The Pipe Adapter

I took a felt pen and drew a circle around the inside of the three inch pipe on the wood (the scratched out lines were a mistake). This was to fit inside of the three inch pipe. Then finding the center of the circle I used the 1 1/2" pipe to draw another circle where the 1 1/2" pipe will sit. You could use a hole saw but I didn't have one that fit so I used a jigsaw for both the outside and the inside. To start the cut for the inside a hole large enough for a jigsaw blade was drilled.

Step 5: Assembly

The wooden adapter was placed inside of the three inch pipe and then the 1 1/2" pipe was inserted into the opening of the adapter. You'll want to do this when the adapter is in the pipe or the adapter may split. If the adapter doesn't fit you can always sand it. Once the pieces were put together holes were drilled and everything was screwed together. Then silicone was smeared on the wood and around the joints.

Step 6: Inserting the Electronics

The grey window crack foam was put around the base so the wifi dongle wouldn't be jammed against the adapter then the pipe wrap foam was cut in half and the dongle put inside. You can see where foam was cut out to make room for the active USB extender. This was put in and a slot was cut in the pipe for the cable. More window crack foam was added to seal against the cover, desiccant was added and the cover was screwed on. I had some exterior latex house paint that I dabbed on and left to dry. This was the base coat. You can paint on plastic if you dab it on and a foam brush works well for doing this but I only had a regular paintbrush. You want to get a good solid coat on. Doesn't look that pretty but it does work. I've done this with a previous mech Halloween costume on the plastic parts as well as with other Halloween costumes and the paint has stood up really well. You need a lot of coats though and using a metal primer definitely adds to the durability.

Step 7: Mounting It

The wifi unit was painted a second time (the paint is to reflect heat and I may wrap aluminum foil around the unit at some point) and then I drilled four mounting holes in an aluminum metal bar and attached it to the satellite dish. The concern was that the plastic mount would break if that was the only thing holding the wifi unit. A zip tie was run through the two holes in the end of the bar and the wifi unit was fastened down, using the original marks on the feed horn for placement because that's where the dish focus should be. The extender cable was run along underneath and zip tied on. Before the extender cable left the dish a drip bend was added to stop a lot of the water from travelling down the cable.

I've tested his thing and it works quite well. It was even tested with a small USB dongle that barely had any range and that dongle picked up a lot of signals but couldn't transmit because of its lack of power. With the high power USB dongle it can receive and transmit. As for range I'm not sure but the signal strength is really good even through trees and bounced off of buildings.

I'm sure this thing can be optimized and if you have any suggestions please feel free to mention them. Thank you.

Step 8: The Feed Horn

I made a paper template but really didn't follow any mathematical rules, I just wanted an angled feed horn. The dimensions are on the paper template and I cut out the shapes from two empty paint cans. The templates were turned inside out because there's a waterproof coating on the inside of the can and I wanted that side on the outside. The small piece and the edges of the large piece have tabs on them and to join the pieces I just basically bent the tabs over each other. To put it on though only one side with tabs was joined and the feed horn was put around the wifi unit. You can see in the picture where the dish is upside down that part of the feed horn was cut to fit around the mounting bracket.

Once the feed horn was wrapped around the wifi unit I folded the last tabs over each other and joined the feed horn together. If you look very closely you can see where a hose clamp is used to tighten the end of the feed horn around the pipe.

<p>Because of the true angle of receive and transmit, which is 15deg off from where the dish centre is pointing we ended up flipping it and WOW :-)</p>
<p>For years I have used aquarium silicone sealant to make things water proof that I needed to be so.</p><p>I suggest when you turn it to vertical that you might try this and get rid of most of the plastic which may be interferring with the signal.</p><p>Just an idea :)</p><p>I suggest aquarium sealant because it is designed to be under water so rain will never bother it :)</p><p>Hope this helps.</p><p>Great idea by the way. I use an internal one myself but with aluminum foil over bristol board for the &quot;satelite&quot; dish :)</p><p>Thanks for this :)</p>
<p>Please forgive my ignorance, but is your design directional (i.e., does it work best in the direction the dish is pointing)? If so, what is this device's primary purpose? Twenty years ago we were all eager to share our WiFi with our neighbors and were happy to let strangers use our bandwidth; today we're afraid some pervert is going to park in front of our houses and download nasty stuff using our IP address. How things have changed! Anyway, I just don't get what a sat-dish-based WiFi extender will do for you. I'm sure the answer to this must be obvious to most readers, but I'm curious and (in this case) completely clueless. Don't be too hard on me! And a sincere &quot;THANK YOU&quot; for all the time and effort you put into developing this Instructable. I'm all for re-using and re-purposing whenever we can, and surplus satellite dishes are a blight. Keep up the good work!</p>
<p>The design is directional and works best pointing at something although side signals are picked up as well. As for a use, I have it pointed at a local library that offers free wifi. Since I'm in a place where the power goes out a few times in the winter (but not at the library, different power grid), I can still access the internet with my laptop in emergencies</p>
<p>Thank you so much for your kind reply. You're extending your WiFi <strong>reception</strong> (not broadcast). Now the re-purposing of the satellite dish makes perfect sense. With increasing numbers of public WiFi hot spots, from coffee shops and colleges to municipal parks and libraries, a person could use your Instructable to get online in areas with a weak but still viable public signal. In our area, that could potentially save students and other people with limited resources as much as $50 a month for broadband internet access, all without breaking the law. Brilliant! </p>
<p>Why not just use a pipe reducer instead of fooling around with the wood, and a pipe cap instead of a flower pot??</p>
<p>I was too lazy to buy one. Besides, if I was using something else besides ABS sewer pipe, like any other kind of plastic or metal tube, I wanted to make sure this idea works for any other projects that come along.</p>
<p>Got it. Thanks great idea1</p>
<p>I don't need this , but it certainly looks cool. I respectfully suggest, if you can't get a dish try using a metal lamp reflector or a metal oil can , in the size used by restaurants, you will need to cut the thing into two triangle if you want a corner reflector, or lop off one end if you want a &quot;cantenna&quot; style. </p><p>Yeah old pringles can calls to me!, The right shaped domed pot lid also works. </p><p>Get a copy of the antenna book published by the ARRL or from Library. All await you, and study up for the test as well, new hobby. Lots of satellite guys on Ham.</p><p>Nice build, I may make one for my wife!</p>
<p>For step 3 why don't you just use a pipe cap? It will be stronger, cheaper, and it will seal itself.</p><p>Same with step 4. A 3&quot; to 1-1/2&quot; reducer fitting is cheaper and stronger than the handmade wood adapter. And, again, sealing will not be a concern. In fact, it's not clear why you even need a different size pipe. Why not make the whole thing out of a single straight 1-1/2&quot; pipe or a single 3&quot; pipe?</p><p>Also, you absolutely do not want to put desiccant inside this container. It will have the opposite effect you intend. Rather than keep the container dry it will actually draw moisture into the container. If your seals leak in the rain then a desiccant isn't going to fix that. Unless you intend to check and replace the desiccant weekly then a desiccant is just going to make failure due to moisture occur sooner than without the desiccant.</p>
<p>One of the reasons I didn't use a pipe cap on the three inch pipe was because I wanted to be able to take the cover off again to access the inside. As for making it one size pipe the wifi unit is too large for the 1 1/2&quot; pipe and the three inch pipe is too large for the original mount. You could change the design if you also change the mount. For not using a reducer I like to build with what I have on hand and I didn't have one. Of course a reducer could be used and it would be easier. This whole thing can be easily modified and made better and I'm looking forward to seeing how others have improved it.</p>
<p>waveguide for WiFi is slightly different dimensions than the end of the Ku-band head! </p><p>For the normal &quot;transmission&quot; wave to the receiver waveguide diameter for 2.4GHz should not be less than 87mm internal diameter. Or a rectangle with sides of 87mm to 43mm (abowe 86.36mm to 43.13mm).</p><p>If you want to understand about the size of &quot;input feed&quot; for a dish - take the crown C-band (3.4-4.2GGts) and Increase it twice</p>
<p>I switched satellite internet companies and had to change satellite TV companies as well. They didn't want the dishes back, just the transmitters. . There must be millions of useless dishes out there, especially in the country where you have no cable access. I'm going to forward this to my tech geek nephew who lives on a farm and see if he will try it. Thanks for the idea!</p>
<p>You can get increased range, I've done it with a cheap and underpowered USB dongle. Just make sure that you have a way of focusing the usb's rf onto the antenna, most likely with some sort of reflector. My design is just an idea, it's not optimal, but it does pull in a lot more signals.</p>
<p>Looks like an awesome project and it's something I might try in the future. I do have a question about the design though. As far as I can tell, the antenna points towards the dish, while a WIFI antenna sends and receives sideways mostly. Is there a special reason for this (was better in tests?) because maybe the signal would improve if the antenna was mounted upright.</p>
It might improve if the antenna was upright and had a reflector behind it. I just made it this way because it was easier. Go ahead and improve on the design I'm sure you can. At some point I probably will too and one of the things I might try is wrapping aluminum foil around the tubes to help focus the radio waves.
<p>1st if it works for your link budget I'd leave it alone. :) If you want to optimize it there are a few things to try. </p><p>The ABS isn't a waveguide or a feed horn. It's a radome to keep the elements out and not mess up the rf propagation. The aluminum foil will have some effect and change that but...</p><p>I'd chuck the whole feed arrangement if I was going for max distance. As the other poster mentioned that alpha antenna radiates a donut pattern. The longer antenna squashes the donut to put more rf toward the horizon. </p><p>I good design goal is a feed arrangement that directs all of the rf towards the dish. Rule of thumb 10% ish larger pattern than the dish to make sure you're using the whole dish. </p><p>Common feeds are a biquad or a &quot;cantenna&quot; You may find the cantenna good enough that you don''t need the dish. There are on line calculators for the dimensions. You'd replace the supplied antenna with a bulkhead N connector and an wire probe soldered to the center. The length of the probe and the placement from the back (closed end) of the can will be determined by the on line calculator. The size of the can will effect the placement that's what the calculator is for. Then hook the threaded part of N connector that is outside the can to the wifi module with a N to rSMA pigtail. the r is for reverse sma. That will mate to most external antenna wifi modules.</p><p> Basically 1/4 wave length from the back of the can and 3/4 wave lengths long. The probe length and distance to the closed end of the can are most critical. The calculator figures out the wave lengths in free space and inside the can which aren't the same.</p><p>A 3.25&quot; inner diameter can like B&amp;M baked bean can is a good choice for 2 gig wifi band. If you can find a cutoff from a 3&quot; copper pipe from some industrial construction site your golden. Ignore and pringles can references. The diameter is to small and it's closer to a quagi antenna then a wave guide cantenna and a crappy one at that.</p><p>The open end of the can would point towards the dish (you can cover it with plastic) The open end the same distance from the dish as the original feed horn is a good place to start. </p><p>It'll make more sense with the online calculator</p><p>|-------------------------------------------</p><p>|</p><p>|</p><p>| |</p><p>| | &lt;probe</p><p>|---------|----------------------------------</p>
<p>Yes, I know the ABS isn't a waveguide, I just wanted something to keep the elements out. I've done the cantenna idea on a previous satellite dish but since I had a bigger satellite dish I thought to do it again. You are right about mounting the antenna vertically though, I just wanted to try this out. What I was thinking of doing was putting a metal cone around the antenna to bounce the rf waves at the antenna for increased sensitivity. But I guess a better way would just be to mount the wifi unit vertically and place a reflector behind that. Would have to change the mounts though and that way I wouldn't have to worry about measurements to much.</p>
<p>instructables messed up my poor ascii art. The probe should all be vertically aligned with the bottom tick mark. :)</p>

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