What you need:
- USB wifi dongle of course.
- USB extension cable. (Max length varies based on quality of cable)
- Metal bowl, about 12" diameter. Got mine from a discount store (Tedi) for $1.
- Optional plastic container with lid. Color or transparency does not matter. I used an empty Cashew nut container.
- Roll of tape. Duct tape or electrical.
- Glue. I prefer Gorilla glue or hot glue. Caulk will work well too.
- Cutting tool or scissors. Just for cutting tape.
- Needle nose pliers. You may need something better depending on the thickness of the bowl. Mine was thin and easy to punch a hole.
Step 1: Locate the center of the bowl. Using the pliers, punch a hole large enough to fit the end of the USB extension cable into it.
Step 2: Tape the hole so that there is no metal to metal contact with the USB connector.
Step 3: Insert the USB extension cable and neatly secure with tape or glue. Secure both sides. I made mine water tight.
Step 4: Cut a hole in the center of the container lid. Again large enough for the USB connector.
Step 5: Glue the lid to the dish. Ensure the lid is faced upward so the plastic container can be attached easily.
Step 6: Insert the USB wifi dongle into the extension port.
Step 7: Attach the plastic container to the cap.
Step 8: Plug it into your computer and point it toward the direction you require.
Modify the design to fit your needs. A larger bowl should produce better gain, but it is also important to ensure the dongle is positioned within the bowl in a manner that signal is reflect directly toward it. The slope of the bowl will determine where the perfect focal point is located. It's not rocket science.
I was temporarily assigned away from my normal duty station at Grafenwoehr. I could not get good signal with my 3G dongle, which I used for mobile internet. This 15 minute project solved the problem.