Intro: Repurposed Satellite Dish Antenna Captures Wi-Fi and Cell Phone Signals
When I moved from San Antonio back to rural North Carolina, I found myself completely unable to get a wi-fi or cell phone signal where I lived. The only way for me to get a cell signal at all was to drive over a mile in either direction from where I liveed. I first thought my problem was my cell carrier. I decided to change carriers so I had several friends check out their signal strength while they were visiting me so I could better decide which carrier to go with. Of the three other major carriers we checked, not one could get a signal at my house. It was apparent that my problem was my location. I was at the bottom of a shallow valley. It was uphill in nearly any direction from there.
I had to find a solution. I checked into an external antenna for my cell phone but found they cost nearly $50.00 and there was some question about whether they actually work. I knew there had to be a better way. While working in my yard one afternoon I noticed an old satellite TV dish on top of a pole in my backyard. It had been left there by the previous residents. Suddenly a light bulb came on. I grabbed some wrenches, took down the dish and held my cell phone next to the antenna's horn and pointed the dish in various directions. I was amazed to find that I got full signal in one direction. I could not believe my eyes. I went from no signal to full signal and had not spent a dime or changed anything on my cell phone. Just to make sure I made a call using speaker phone and found that this thing truly did work.
The next test came when I took the assembly inside the house to try it. With aluminum siding on the house I have problems even getting a television signal using a rabbit ear antenna. To my surprise, I got two to three bars inside so long as I pointed the dish at a double window in my living room. I no longer missed calls and I didn't have to leave home to talk on my cell phone. Using a blue tooth headset really worked well. It isn't an ideal setup but it worked and it didn't cost me anything. It was also a great way to recycle that old satellite antenna that would have ended up in the trash otherwise.
I had a friend give me another old dish that I used for wi-fi. I mounted it on the pole the other dish came off of. After some tweaking I found several really strong wi-fi signals that I could not get without the dish thanks to some really great neighbors with unsecured networks. ; )
Step 1: Pointing the Dish Antenna at a Signal Source
You would think it would be simple to align a dish antenna with a signal source, but it isn't. Even trying to explain this without a lot of complicated math formulas is a bit difficult. The problem is that satellite dish antennas, like the one I use, are of the offset design. This means the dish doesn't "look" where it would seem to. In the graphic there is one line that shows the apparent view of the dish. That one comes right off the front of the dish. That is not where the dish is "looking" so don't try to use that to align the dish. If you do you won't get any signal. The other line shows the "actual view" of the dish. Notice this line is a bit offset from the center. This is the line you must point towards the signal source (wifi router or cell phone tower). Keep in mind that dish antennas are very directional. Even moving the dish an inch or two in either direction can make you go from no signal at all to five bars. Also, the further away the signal source is the more difficult the alignment will be. It is a lot easier to find your neighbor's wifi signal than it is to find a cell tower 3 miles away. You will need to play with the antenna alignment to find the signal and fine tune it for maximum signal. Patience is a must.
Step 2: Fine Tuning the Dish Antenna
After my initial eureka moment, I started tweeking the antenna / cell phone assembly a little. First I held the cell phone in front of the dish's horn and turned around in the yard to see which direction I got the strongest signal from. When I found that sweet spot I held the cell phone against the horn while moving it up and down, left and right in front of the horn to see which position provided the strongest signal. For my phone I got the best signal with the bottom edge of the cell phone near the bottom of the horn. I also found that the signal was even stronger if I tilted the phone a little to the side.
Step 3: Finishing Up
With that information I went in the house and made a small foam core holder for the cell phone and used duct tape to attach it to the dish's horn. I kept the front of the holder pretty short so I could still access the buttons to dial a number. I sat the whole assembly on top of an old radio cabinet and pointed the dish at the double windows in my living room. Now I never miss a phone call.
Step 4: Taking It Further
If for some reason (like you live in the mountains) and you need to mount the antenna booster outside to get a signal, it would be a simple matter to weather proof the cell phone with a plastic sandwich container. You could still use a bluetooth headset to receive your calls.
Also, I found that this setup works even better with Wi-Fi. Just use one of those little USB WiFi antennas with a USB extension cord. Place the USB antenna in front of the horn like I did with the cell phone, tweek the position, and then mount it using duct tape and some plastic to weatherproof it. Again I went from no signal to a usable signal.
Hopefully someone else can benefit from this instructable as I have. Best of luck with all of your projects.