A Quick, Dirty, and Effective Reflector for the Lab Network

This week I moved the Wireless Router to the front of our property. The router of course has a rubber ducky antenna. The nature of a monopole antenna is to radiate the signal in all directions equally forming a doughnut like cloud of radiation. Because the signal of the box is omnidirectional and it is literally located on the front edge of our property this means I am radiating signal to the neighbors across the street.

The solution is to whip up a parabolic reflector to:

1. keep the signal toward my property
2. extend the signal to the back reaches so I can listen to internet radio in my fabrication shop
3. do it all in 10 minutes... ok 15min. so I can get a coke and the materials together.

You probably have these materials around the house:

1. aluminum foil
2. sheet of card stock (8.5 x 11 or so) I am not being very mathematically precise here, it is a quick dirty job
3. glue stick or some adhesive substance to adhere our foil to the shape card stock.
4. Skewers—to help you shape the parabolic form. I have seen people use wire and even string before; anything to help it pull into shape.
5. and lastly I used poster tack—that blue goo but it isn't pictured

1. Put glue on the entire face of the card. The edges are tough to get you may want to put a piece of paper down so as not to smear glue on the table.
2. Tear off a piece of foil larger than the card
3. Lay down the foil and smooth from the inside to out. I used the glue stick container because it was nice and smooth. You can use an small piece of card stock, credit card, etc.
4. After that I turn the piece so that the paper faced up and burnished it again to help it adhere.

1. trim off the foil that is over the edge of the card
2. using the skewers make 4 holes in the foiled card. make these holes equidstant to each corner such as 1/2inch from each edge. it is ok to estimate :D, quick and dirty, right?
3. insert skewer,
4. shape the card to a estimated parabolic curve
5. affix it with some adhesive to stop it from unfolding. I used blue poster tack.

You will want to place the card so that the deepest part of the curve is roughly 2.3 inches behind the monopole. For me I have a wall behind the router. You arrangement will require you to attach it in some fashion.

My results, I spent an extra 30 minutes noodling arund with the curve and I was able to get 3 to 4 dB attenuation behind the reflector (i.e. the nieghborhood) and 3 to 5 dB gain on the outer limits in front of the reflector.

your mileage may vary. good luck.


here are some links to more exacting reflector tuts:
http://www.binarywolf.com/249/signal_strength.htm
http://www.youtube.com/watch?v=YOBfxbpxosA&feature=related