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)
-thin sheet of metal
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.