May 132012


I wanted to be able to locate wifi signals, so I built a directional antenna and strapped it onto my panorama robot. The waveguide style antenna built from a used can (explains the name cantenna) looked to be the easiest to build. I bought a pigtail with an N male connector to RP-SMA male connector.  I plugged this into my Alfa Network AWUS036NH. I then fired up inSSIDer and used PuTTY to control the Arduino sketch and aim the antenna.

The signal strength was not what I expected to see at all. I assumed this antenna was directional and would be strongest when I pointed it directly at the AP. It was strongest pointing at about a 45 degree angle to the left of the access point. I’m a complete n00b when it comes to RF, so any feedback on why I’m not seeing what i expected for results would be greatly appreciated.

Note: Will update post if/when I have an answer.


I am a complete n00b when it comes to build antennas. I goobered another can on there and it works a lot better. I have to give a great thanks to several redditors for pointing me in the right direction. I’m always impressed with how helpful people are. Even better, I’ve got some reading to do now.

I’ve included links I found useful or interesting and more pictures.

Antenna Links:


Aiming Antenna Links:

Visualization Ideas:









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